Meredith Rodney McKay

"Well I've discovered you're pretty good under the threat of impending death!"

- John Sheppard

"Under the threat of impending death, you perform complete miracles."

- Cameron Mitchell

Dr. Meredith Rodney McKay, better known as Rodney McKay, due to his dislike of his real first name (he is called 'Meredith' by his sister and briefly 'Rod' by Daniel Jackson), is a brilliant Canadian astrophysicist, and one of the leading experts on, not only the Stargate and wormhole physics, but also Ancient and nanite technology in both the Milky Way and Pegasus galaxies. Although he is able to formulate many ground-breaking ideas on a broad range of subjects, his phobias and arrogance continually serve as a hindrance to people acknowledging his abilities.

McKay was initially involved with the Earth Stargate program and later as the leading scientist on the Atlantis expedition. He is a self-important scientist with a great deal of knowledge but, according to Colonel Samantha Carter, has no feel for it.

When he joined the expedition to Atlantis, he was very eager to be part of the expedition and he continues to excel in many scientific aspects. He is also a member of the First Atlantis Reconnaissance Team. Despite his mannerisms and insecurities, he does occasionally show endearing moments of vulnerability and bravery. Together with Dr. Radek Zelenka, he works miracles with the tools at hand, but he has trouble acknowledging other people's work.

Early life
"I had a not-so-comfortable childhood. My parents hated each other, blamed me. Music…was my salvation. It had this…perfect order for me."

- Rodney McKay

McKay was born in Canada sometime in 1968. He said that when he was six years old, his father read him Moby-Dick and ever since then, has recurring nightmares that he was eaten by a whale. He wanted to become a concert pianist, but when he was twelve, he was asked by his teacher to quit, since he was described as a fine clinical player, but had no sense of the art. McKay claimed to have won an award for his acting skills as a kid and could have made a career out of it, but chose not to. At some point in his childhood, he spent a few months in a scouting organization, the Fort McMurray Eager Beavers, until they asked him to leave, but he kept the manual ever since. In grade six, McKay built a non-working nuclear bomb for the science fair. This prompted a visit from the CIA.

During his education years, he earned two PhDs in Physics and Mechanical Engineering. He knew Malcolm Tunney, another genius, and a rival of McKay. Though McKay claimed that he was always smarter than Tunney, he always wanted to show off his success, especially to annoy him. He also once admitted to have "toked" Cannabis when he was in University and claimed he didn't feel any adverse affects, apart from itching and a desire to eat an entire loaf of white bread. He has a younger sister named Jeannie Miller, who is also a talented scientist, but when she decided to start a family, they had a massive argument and did not speak for four years before Rodney saw her again. He has said at times that he is [mortally] allergic to citrus. .

At some point, he began working for the Stargate program. Despite being Canadian, he worked at Area 51 for the United States Air Force and was on their payroll. He became the foremost expert on the Stargate, after Samantha Carter. For instance, he knew that when Carter got the Stargate working with three supercomputers, they ignored 220 of the 400 feedback signals the Stargate can emit during any given dialing sequence. However, despite this knowledge, he was never particularly interested in wanting to see it. Due to the secretive nature of his job, he had not published a theoretical paper to the public in an undisclosed number of years. He once claimed that one of his ideas was stolen by TV physicist Neil deGrasse Tyson.

2002
When Teal'c failed to materialize through the Stargate back to Earth, Colonel Frank Simmons hired McKay to help, but they had a 48 hour deadline before they should resume gate activity. McKay was immediately infatuated with Major Samantha Carter and tried to talk to her, but the conversation quickly turned sour when Carter realized that he was the one who suggested the 48 hour deadline because he thought Teal'c was already dead, believing that the Stargate's data storage program had already degraded Teal'c's pattern so much that the Jaffa could never be restored. This led to Carter calling him a "jerk" and told him to "suck on a lemon" which was no small remark considering McKay's fatal lemon allergy. McKay remarks, "I've always had a thing for dumb blondes". After the situation was resolved with McKay's theories about Teal'c's pattern being proven incorrect-, McKay was ordered to go to Russia to help with their Naquadah generator technology. McKay initially protested, stating that he was a civilian and didn't follow orders, until Carter pointed out that he was still part of the United States Air Force payroll.

A few months later, he returned to the States to help Major Samantha Carter with a solution to shut down the Stargate before Anubis used it to destroy the Earth with the Stargate destroyer. He suggested they use an EMP generator to shut down the Gate, but that only made things worse. In the end, the solution to the problem was to use the X-302's hyperdrive to make a "short jump" (in relative terms which means still a really long way) with the Gate strapped to the underside of the 302. This sent the Gate far enough from Earth that it wasn't effected by the Gate's explosion. Carter later kissed McKay on the cheek, which he interpreted as meaning that Carter no longer hated him.

2004
When the Ancient outpost was discovered in Antarctica, Rodney McKay was one of the scientists involved in studying the technologies of the outpost, namely the outpost's control chair. Through numerous efforts, including trying the chair himself twice, and attempting to interface it with Human computers, he was able to determine (with reluctant assistance from Carson Beckett) that it could only be used by somebody with the Ancient Technology Activation Gene. Later, he assisted in setting up the outpost's Zero Point Module to connect to Earth's Stargate, which activated the connection to Atlantis. He joined the Expedition to the Pegasus Galaxy and was one of the key members to determine the various functions of the city. Along with that, he determined that the city's last working Zero Point Module was nearly depleted.

Wanting to work Ancient technologies, McKay acted as the guinea pig for Carson Beckett's first human trial of the Ancient Technology Activation gene therapy. The test proved successful and McKay attached an Ancient personal shield to himself, testing it out by having Sheppard shoot him and push him off a balcony. Although he was jubilant about surviving such occurrences with the shield on, he determined that he could not eat or drink with it. However, when Weir suggested that he could "trap" the "shadow" since he would be protected by the shield, it fell off. Sheppard was assigned in his place. When the creature fed off the energy from the Stargate, McKay put the device on again, and threw a naquadah generator through the gate to M4X-337, sending the creature trapped.

When Sheppard and Teyla discovered a massive storm covering 20% of Lantea's surface that was also heading for Atlantis, McKay discovered a way to power Atlantis' shield by using lightning strikes from the same storm that seemed poised to destroy the city. When the city was temporarily evacuated, McKay, along with Weir, Sheppard and a couple of marines stayed behind to disable the grounding stations, when several Genii soldiers, led by Acastus Kolya stormed the city after the first contact with them went sour. They tried to retrieve supplies the Tau'ri promised (medical supplies and C4). However, McKay managed to have bought enough time so Sheppard could save the city and McKay managed to have activated the city shield before being wiped out by a massive tsunami.

One of his first acts of bravery during his time in Atlantis was on the Light Bugs' Planet where he stood up against a Wraith by distracting him before it killed Sheppard.

2005
When searching through the city after the Lantean storm, some of his team members inadvertently released a nanite virus, which kills its victims after terrorizing them through hallucinations. McKay was infected with the disease, after he hallucinated a ghost attacking him. However, he did not die, since he had the ATA gene. He figured that an electromagnetic pulse would stop the attacks. After the machine didn't work, Sheppard used an overloaded naquadah generator and detonated it over the planet.

When Sheppard invited Chaya Sar to Atlantis, he originally regarded her with hostility, especially when he realized Sheppard had certain intentions of her. He later discovered that Chaya Sar was actually an Ancient.

He and the team went to Dagan to search for a ZPM, after an alternate Weir gave him five addresses with a guaranteed ZPM on them. Allina, one of the Daganians took a fondness for McKay, but was, at first oblivious to it, until the team told him. After Kolya returned to also acquire the ZPM, the team planned to stop them, and did. The team had acquired a ZPM, but since he told Allina, who was a member of the new Quindosium that the Expedition weren't the Lanteans they hoped and took the ZPM until the Ancients came back to reward, despite the fact they all ascended. McKay tried his best to convince of the impending Wraith siege, but lost.

Before the siege McKay went with Dr. Grodin and Lt. Miller to the Ancient defense satellite to reactivate it and to take care of the three hive ships. One was destroyed before the satellite was. During the siege, the Daedalus arrived and beamed down the ZPM Atlantis desperately needed to protect the city. In the process, he was cornered by Wraith guards. After a spontaneous show of courage, during which he accidentally ejected the magazine of his sidearm, Teyla managed to save him and the ZPM was installed and the shield activated before the Wraith Darts made a kamikaze run on the city. He was later working with Zelenka to cloak the city to make the Wraith believe the city is destroyed.

He was on a mission on Thenora to search for any survivors during the Wraith culling there. However, there was none. He was later scooped up by a Wraith beam with Laura Cadman, before the dart was shot down. After discovering that there was only enough power to save one of them, they beamed out McKay, who fainted. After he regained consciousness, he discovered that Cadman's consciousness is inside his. He had to live with putting up after Cadman until Zelenka's team found a solution. During that time, they found it hard to co-exist. Cadman agreed to help McKay through his first date with Katie Brown, which ended up Cadman taking control of Rodney and left during it. He also found out that Beckett was quite fond of Cadman. Eventually, the strain of having two separate minds in one has caused a near fatal seizure, and Zelenka's team wouldn't find a solution in time. However, McKay worked out how to save both of them, by using the Stargate's crystals. Before they went through the procedure, Cadman took control of McKay's body one last time, and used him to kiss Beckett, in case it wouldn't work, which it did.

He was in charge of Project Arcturus found on the Doranda outpost. He convinced Weir and Sheppard that after the first attempt resulted in the death of an expedition member, they should try again. However the second attempt resulted the destruction of 5/6th of its solar system.

By the end of the year, he and the team was taken by Ford's coalition, to formulate a plan to destroy a Wraith hive ship. McKay worked on fixing the Wraith dart, but was left behind on the mission. McKay needed to escape to inform Weir of Ford's plan. However, in order to that, he had to inject a considerable amount of the Wraith enzyme to knock out two guards, and escaped. He went through withdrawal and managed to completely recover. Dr. Beckett thought that his own stubbornness helped him through. He later found out where Sheppard and the team were and took part in the Battle of Edowin, where two hive ships destroyed each other.

2006
He was test flying a newly-repaired Jumper 6 after it was shot down on Olesia when one of its engines failed, causing it crash land into the Lantean Ocean. While trying to find a way out of the sinking craft, he had a hallucination of Samantha Carter, who told Rodney to use whatever power left for survival, because Zelenka and Shepperd were working on a way to rescue him. However, McKay ignored "Carter's" advice and attempted a different means to get out of the ocean. The hallucinatory "Carter" tried to delay McKay by being one of his fantasies, which in the end, didn't work. McKay then used up most of the Jumper's remaining power trying to raise it out of the water. However, the weak distress signal he was transmitting attracted the attention of a Flagisallus. The fish was the reason Zelenka and Shepperd managed to have found McKay and rescued him.

McKay once cited Atlantis' chain of command, stating that in the event that Weir and Sheppard are unavailable, McKay would be in charge. However, since Weir and Sheppard were taken over by the consciousnesses of Phoebus and Thalan, and trying to kill each other, Colonel Steven Caldwell stepped in, as it was a military operation. McKay regarded that with hostility and did not agree with some of Caldwell's action. Despite this, after the end of the crisis, he had said that he did a good job, though McKay never said it to him directly.

After a Wraith named Michael Kenmore escaped and made aware of the Iratus bug retrovirus, a hive ship proposed an alliance to use the retrovirus against rival Wraith, so they would turn human and become an alternate food source. McKay managed to have acquired vast amounts of Wraith technology to help against the war with the Wraith. After one of the first trials failed, McKay looked at the damage the hive sustained and agreed to stay there with Ronon. However, by the time the Expedition realized they were double crossed, McKay and Ronon were taken prisoner. As the two hives went on its way to Earth, Ronon and McKay escaped and tried to overload several systems, resulting in the destruction of the ship. However, they were found and rescued in the Battle of the Void.

When SG-1 came to Atlantis to implement a plan by using a Stargate next to a Pegasus black hole to dial to the Supergate in the Milky Way, to prevent more Ori motherships from getting through, McKay initially thought the plan would not work, since it is very unlikely to jump a wormhole from a regular Stargate to an even bigger one. However, he helped Lt. Colonel Samantha Carter with the calculations on board the Odyssey to calibrate a nuclear warhead to jump the wormhole from the other end of the Stargate in the Milky Way, which was right next to the Supergate, to the Supergate. Through trial and error (using two warheads rather than one, and destroying a pursuing Wraith Hive Ship, the mission was successful. Also, McKay recited Carter her "help" she gave him whilst he was trapped in the back of the sinking Puddle Jumper, where he was forced to confess she was "partially" naked.

McKay's problems of attempting to resurrect Project Arcturus, eventually caused him to seek the help of his sister, Jeannie Miller, a fellow scientist whose intelligence matches his, but lacks the worst of his most aggravating personal qualities. She first thought of a way to bridge two universes, which would cause a benefit for the succession of the project. This ultimately failed as the other universe was threatened to be wiped out from existence, and in order to shut it down, meant the depletion of their ZPM. Although there is obvious friction in the relationship with Jeannie, McKay manages to reconcile his differences with her.

In the space of just a few months, he was shot twice. The first time was when one of Keturah's people fired an arrow into his Gluteus Maximus, and the second time was when Sheppard mistook him for a Taliban soldier and barely missed his chest. He has seemed to have recovered from the two events, but it is said that he is prone to Sciatica since being hit in the arrow. Despite his embarrassing injury, McKay insisted on joining the mission to save Ronon saying Ronon was like a brother to him, something which Beckett didn't really believe him about. McKay attempted to go help his friends against the Wraith despite barley being able to walk, but fought with Beckett over a gun for so long, it no longer became necessary. When Ronon's life was in danger, McKay and Beckett saved him by McKay flying a Puddle Jumper down in front of him and Beckett killing the Wraith he was fighting with a drone weapon. McKay admitted that it was his idea, but balked when it was revealed that Ronon was gonna kill anyone who killed that particular Wraith before him. However, after Ronon simply hugged Beckett McKay got indignant about not being thanked for his part in the rescue but was mollified when Ronon thanked him. McKay was the one who flew the team and Ronon back to the Daedalus after the successful rescue.

He, along with Carter had figured out a way to go back and forth to Earth and Atlantis without the use of a ZPM and waiting three weeks while sitting in the Daedalus, by building the McKay-Carter Intergalactic Gate Bridge. The first trial worked, but found an Ancient ship named the Tria with Ancients, who later took back the city and told the Expedition to leave. McKay was transferred back to Area 51 for an undisclosed amount of time, until he learned the Asurans took control of Atlantis. McKay worked with Beckett, Sheppard and Weir, as well as Teyla and Ronon to help take back control of the city.

2007
After the successful take back, he complained that two of the three ZPMs were taken away for use of the Antarctic outpost and the Odyssey to defend against the Ori crusade in the Milky Way. He later discovered that a Flagisallus, presumably the same one who gave away Rodney's position under the ocean, visited Atlantis. McKay took a look through the binoculars, and called him Sam, after Samantha Carter. However, at the same time people started to hallucinate several worried Ancient scientists. He eventually learned that the Flagisallus used this to warn them of an impending coronal mass ejection. McKay reluctantly used Sheppard's plan to use a ZPM to strengthen the Daedalus' shield, to deflect the ejection, which worked.

He came across an ascension lab, which has augmented his body to a point, where he was eventually capable to ascend. He had developed several new-found powers including Telekinesis, Telepathy, Healing powers, improved hearing and increased intelligence. However, the mind altering made him more accessible to ascension, and if he didn't figure a way how to reverse the process, or ascend, he would've died. McKay used Sheppard's help to meditate, since he spent time with the People of the Cloister. When he wasn't trying hard enough, he decided to better use his time working out a new form of advanced mathematics, improving the Daedalus' shields and even plans on having a hyperdrive engine on a Puddle Jumper, which they used later on. McKay later found out that he can choose to de-ascend again; however, upon further meditation, he finds still can't reach the requirements for a human to ascend, and suffers a near fatal seizure. He eventually figured out a way to save him through using his telepathy to Beckett.

He managed to have found time to see more of Katie Brown since their encounter with Cadman the last time. He also discovered that the civilization of M4D-058 was a real-life representation of an Ancient "computer game" McKay competed with Sheppard with. He also learned that the conflicts between Hallona and Geldar are real-life too. However, McKay found a way to fool them all to avert a war.

McKay was deeply affected by the death of Beckett, who was killed in an explosion. He felt somewhat responsible when he didn't go fishing with him. When he was hallucinating Beckett, Rodney tells him that he considers him a best friend. McKay was one of his pallbearers and was the one to tell Beckett's mother that her son had died.

Following the team's success in stopping the Asurans, they planned on building a fleet of warships to either attack Earth or Atlantis. Colonel Abraham Ellis tasked McKay with finishing the Horizon weapons system, intending to wipe out the Asurans in a preemptive strike. After the delivery proved a success, the Asurans retaliated by sending a Stargate satellite to destroy Atlantis. McKay submerges the city, but that only buys them a little time. In the end, he and Sheppard work together to ensure that the city would take off to evacuate into another planet. However, within minutes off entering hyperspace, it shuts down, with only 24 hours before power would fail, and the occupants would be exposed to space. While working to patch up damaged power conduits, McKay collapses the city's shield to cover only the central tower to conserve power. He also participated in an operation where they are to clear a path for Atlantis while crossing an asteroid belt, and reactive the nanites in Weir to save her life, against Sheppard's wishes. When it is discovered that power levels have dropped below the requirements to jump, he worked on finalizing a Puddle Jumper with a hyperdrive, and take Weir along to recover a ZPM in Asuras to restore Atlantis's power. The mission is a success, but at the cost of Weir, who assisted in implementing a Wraith attack code in the Asuran central data core.

While exploring a planet McKay believed could house some technology, they inadvertently brought back entity, which infects their hosts with nightmares, until it could have the capacity to kill hosts in their sleep. After killing Kate Heightmeyer, the entity finds its way into McKay. He suffered a nightmare where a killer whale was after him while rowing back to Atlantis. Fortunately, Sheppard, using virtual reality, saved him, only to have the entity passed on to Sheppard. McKay was able to get into Sheppard's mind and helped defeat the entity.

The expedition later fell victim to a mutated strain of Kirsan fever, causing them to lose their memories until they die. McKay attempted to work on altering the air conditioning system to spread the sap of the enchuri plant. Unfortunately, McKay started losing his memories also. Fortunately, though Teyla's help he was able to finalize the program (turns out that before losing his memories, all he needed to do was to enter the program).

Towards the end of the year, his sister was kidnapped by Henry Wallace, to perfect nanite coding. His efforts to rescue her has got him captured as well. However, he chose to escape, but that caused Jeannie to be infected by nanites. He was rescued by Sheppard, and had to shut down the nanites before curing her epilepsy, which would kill her in the process. He enlisted the help of "Todd" to shut them down.

2008
After learning that there are over thirty Asuran ships in Pegasus, he and "Todd" continued working on recalling the Asurans back into their homeworld, without. Even after Daedalus and Apollo were retrofitted with Asgard plasma beam weapons, he asked for a few hours to finish. However, it took him another week, and seven destroyed Asuran ships until he could finally admit that progress halted. He later had another idea; since all the Asuran ships were recalled to their homeworld to gather strength, he planned to construct a Replicator block capable of attracting all the nanites to a massive dense blob. He eventually constructed FRAN (Friendly Replicator Android) to send down to the planet, attract all the nanites and hopefully, they would overload the ZPMs to destroy it. During the Battle of Asuras, McKay beamed down to the planet to overload the ZPMs while FRAN did her work. However, the mass destroyed the planet's power grid. In response, he dailed up the attraction, sinking the mass into the core, which caused the entire planet to be destroyed. After the events, he gladly deleted the planet from their database.

He planned to marry Katie Brown, since they had been together for two years. However, just as he was about to propose, the city went into a quarantine lockdown, since the tweaking from the events of the Kirsan fever the year before. Later, he realized that he still wasn't ready, after Katie found out about his plans. She misconstrued this as a means of breaking up with her, and was transferred at her request back to Earth.

Several weeks later, he, Carter and Keller went to M5V-801 to talk some locals into moving out of their settlement, which was prone to several tremors daily, and had unclean air. However, en route, they fell into a Genii mining facility. Knowing they were trapped, he and the other two made several attempts to escape, though in the process, their combined weights seriously compromised the structural integrity of the building. Eventually, they managed to escape by roping down to a tunnel leading out of the mine, with moments to spare before the facility fell into the bottom of a deep underground pit.

After Teyla was kidnapped by "Michael", he and his team worked hard in trying to find her. This included unwittingly rescuing Beckett, who turned out to be a clone. He was with cloned Beckett until his cells deteriorated and had to be put into stasis until a cure was found for it. He often talked to him about events that had happened, in secret. Eventually, Teyla was rescued, and McKay was responsible for delivering her baby, albeit very reluctantly.

When an alternate version of the Daedalus mysteriously appeared in orbit over M35-117, McKay and the team investigated. After the ship transported itself to an alternate reality, McKay found the source, as well as an alternate version of their team, dead. He also noticed that another version of himself designed the alternate reality drive. He was eventually able to return the ship to their own reality by reversing the drive. He also brought back sublight engines to aid in winning a fight against an alien ship (that and a fleet of F-302s from the alternate Atlantis). Eventually, he and the team return to their own reality, where McKay began to work on ironing out the bugs and make his own alternate reality drive, though Sheppard does not wish that to happen. He was later allowed to hold Torren, despite an earlier incident where he was injured during their last encounter.

During a mission on M44-5YN, he was infected with an ailment known as Second Childhood, a disease that was quick at reverting McKay into a child-like state. He decided to do a recording every day, to see how things progress. He starts with his name, his position, where he is and saying Pi in 12 decimal places. On the first day, he was able to do so. However, by day 6, he started to forget everything. By day 10, he could only remember his name and barely remember Atlantis. By day 15, he calls himself "mister" Rodney McKay. And by day 18, he couldn't remember anything. He only had a few days left until he dies. Ronon came up with a solution; the shrine of Talus. However, Keller was able to cure him, since the radiation shrunk the parasite enough to be removed. He fully recovered. It was also revealed that he loved Keller.

However, he learned that he needed to fight for Keller's affection, when he found out Ronon also wished to be with Keller. When he assisted Keller in vaccinating the people of M33-985, Keller was abducted by Kiryk. McKay assisted Ronon in finding her, and helped work out a way to escape, namely by repairing the damaged teleportation device, which Kiryk used to buy the others time to escape the planet from a Wraith army. After the events, McKay and Ronon decided that instead of fighting for Keller's affection, they should let her decide.

When Dr. Daniel Jackson came to Atlantis, McKay reluctantly helped in finding Janus's secret lab. However, while researching the lab, an Ancient device activated, alerting the Vanir (rogue Asgard) to their location. They kidnapped McKay and Jackson, and forced them to activate the Attero device, a device capable of destroying Wraith ships entering hyperspace, but also destroyed active Stargates. They eventually managed to stun their captors and manually deactivated the device. They were later retrieved by the Atlantis Expedition.

After Keller told Ronon she was interested in someone else, McKay started getting close to her, and eventually asked her to join him on Earth to attend a scientific presentation hosted by his nemesis, Malcolm Tunney. It was later revealed that Tunney had indirectly stolen Jeannie's research on matter bridges through alternate realities, and use it to channel heat through to another Universe, thus solving global warming. However, while testing the bridge, it refused to close, causing the Kramer Innovations building, which was protected by a shield, to freeze, with everyone inside. While McKay and the other scientists tried to work out a solution, Keller attempted to call Stargate Command. However, she became trapped. After McKay was able to shut down the bridge, he ran to Keller's rescue, and revived her. Keller confessed her feeling towards him, and they have since started a romantic relationship together.

2009
When "Todd" alerted Atlantis that the Wraith constructed a super hive ship, McKay and the team attempted to stop it before it became fully powered. However, the ship already proved to be too powerful, and disabled the Puddle Jumper. While Sheppard went to Earth to stop the ship when it arrived in the Solar system, McKay stayed in Atlantis, which flew to the outskirts of the Milky Way. When they attempted to dial Earth, they connected to the Stargate in the ship, which superseded Earth's Gate, McKay and a team went onboard to destroy the ship. However, he witnessed Ronon die (though he was later brought back to life). After he stopped Sheppard from detonating a nuclear warhead from his F-302 inside the ship. They later Gate to the Alpha Site to remote detonate the weapon, which succeeded. He later returned to Atlantis, which by then, landed on the Pacific Ocean outside San Francisco.

Alternate realities

 * An alternate reality Dr. Rodney "Rod" McKay came to our reality to prevent his from being destroyed by a power generating experiment. The project was shutdown, but the exotic particles were still being created in his reality. Rod, our McKay, and his sister found a way to disconnect their realities, stopping the creation of any more particles. The plan was successful and Rod was sent back to his reality, however this depleted the ZPM.
 * In an alternate reality the McKay wears glasses and is, according to Major Evan Lorne a "dotcom millionaire smart-ass". He was a wealthy high-tech industrialist and was once married to Major Samantha Carter, until they got a divorce. When Carter from our reality accidentally transported herself to that reality, partly due to their Carter, she asked McKay for help bridge his universe with Carter's, something he has done with his sister back in her own reality. Initially, he was reluctant, but when the US Government forced him to work for Stargate Command, he helped build the bridge, since the government from that Universe thought Carter would be more trouble than she's worth. 
 * In one alternate reality, McKay designed and built the Alternate reality drive and fitted it on an alternate Daedalus. The drive later turned out to be flawed, as it went out of control and shifted to other universes with no way to stop it.
 * In an alternate reality, Sheppard's team went onboard the alternate Daedalus and starved to death onboard the runaway ship.
 * In an alternate reality, McKay was a part of an Atlantis Expedition and an Atlantis Recon team that did not include John Sheppard. He was also seen wearing a wedding ring, but never discussed having a wife. At some point he opened an inter-dimensional rift to an unknown reality more similar to ours in which John Sheppard had joined the Atlantis Expedition and led AR-1. With the help of one Detective John Sheppard that McKay later met in his own reality, he was able to stop a Wraith from transmitting the coordinates of Earth to the others in the Pegasus galaxy. Unfortunately, the transmission bled into our reality, signaling "Todd's" newly advanced hive to the location of Earth.

Alternate timelines

 * In an alternate timeline, Dr. Rodney McKay was the lead astrophysicist working at Cheyenne Mountain. Unlike the McKay in the proper timeline, he was not allergic to lemon and, in fact, considered Lemon chicken his favorite food. However, like the McKay in the proper timeline, he was infatuated with Samantha Carter and wished to name the Puddle Jumper a "Gateship."
 * In an alternate timeline, McKay stayed behind on the newly discovered Atlantis to attempt to open the bay doors of the Puddle Jumper bay. He drowned as the control room of Atlantis became submerged. The alternate-timeline Weir called him "heroic" for giving his life on the chance that the city and the expedition might be saved.
 * In an alternate timeline when Sheppard traveled to 48,000 years in the future and Michael successfully took over the Galaxy, McKay eventually resigned when the IOA and the Earth military abandoned helping the humans of Pegasus. On the way back to Earth, he became romantically involved with Keller, until she died due to complications with the Hoffan drug. He then spent 25 years trying to figure out a way to leave a message for Sheppard in the future that would allow him to work out a way to return to the past and undo those events.

Behavior
"I'm Dr. Rodney McKay, alright? Difficult takes a few seconds; impossible, a few minutes."

- McKay

Contrary to the 'Polite Canadian' stereotype, McKay is often one of the most arrogant and condescending people known to both the Stargate Program and the Atlantis expedition. He often verbally abuses his peers, particularly Radek Zelenka, for their perceived "lack of intellect" or imagination. His attitude is one of exasperation, wondering that they can hold down a job, and yet, he is occasionally forced to admit that his colleagues are useful. However, despite his irritating demeanor, almost everyone on the Atlantis Expedition is either a friend, or on friendly terms with him.

Despite his shortcomings, McKay has performed extraordinary acts of heroism and bravery as early as the first few weeks on the expedition, ranging from taking the initiative to hand-carry, and then throw, a naquadah generator through the Stargate in order to lure a shadow creature out of the city, and evacuating entire populations from planets about to be culled by the Wraith. In one mission, he was torn between staying with a dying Brendan Gall, or going to help the outmatched Sheppard. The badly wounded Dr. Gall told McKay to aid Sheppard. He refused to leave until Gall, who was already near death, killed himself. McKay saved Sheppard from the Wraith and the combined efforts of the two were enough to save both of them and their ship.

Another example of this was when, despite hurt, he joined a rescue mission for Ronon, claiming to be close friends with him, which Beckett was skeptical of. During the rescue, he at least tried to go out of his way to help Ronon, fighting Beckett over a gun to go out and fight. He and Beckett then formed a plan that saved Ronon's life and allowed Beckett to kill the Wraith Ronon is fighting. After being assured Ronon won't hurt him for his part in that, McKay was and mollified by Ronon's reactions. He even pilots the Puddle Jumper home, even though he was not a good pilot, but that seemed to have improved over time.

John Sheppard and other members of the Expedition has usually shown full trust in him. An alternate McKay, who went by "Rod" has admitted that he likes McKay for the simple fact that he is able to speak his mind so freely and simply. McKay however, didn't seem to realize that people didn't like him too much because of his arrogance because when Rod said he didn't care if people liked him or not. In one instance, Elizabeth Weir stated that she and the members of Rodney's team love him, which Sheppard, in his own way, seems to confirm, by saying "In a way a friend feels about another friend."

He often provides comic relief in addition to his considerable technological expertise, and his ability to find solutions in situations of imminent death have been used against him several times to motivate him, which always works.

He is also known for repeatedly snapping his fingers several times at once. He often does this when he gets a sudden bright idea, is attempting to remember something or to attract someone's attention.

When McKay had a brush with near-Ascension, his behavior changed somewhat. He spent what time he thought he had left as best he could. He used his knowledge to try to create technologies to help the Expedition, did things to help others personally, such as writing a book about Weir from his perspective, asked Ronon about his scars and healed them, saved Zelenka's life when he was dying, and served the remembrance tea for Teyla's father's death so she wouldn't have to do it alone.

Sometimes Dr. Mckay seems to hallucinate under stress.

Intelligence
"You're smarter than me." "I know."

- Malcolm Tunney and McKay

He often claims on being the smartest person in Atlantis and has identified himself as a Mensa member, and implied an unofficial chapter in Atlantis, thus making him unique among his peers. He cannot stop himself from putting everyone "right" when they are "clearly wrong", usually on the spot, whoever they are and in whatever situation; including bosses, colleagues, and even invading alien captors.

McKay originally turned to science after studying the piano, intending to be a musician, until he was told by his piano teacher that he was a "great clinical player" but had no sense of the art. After turning to science, he discovered that it, too, is an art. Since both Carter and McKay often argue about solutions, she often wins. However, he once told a hallucination of her that while he considers himself as smart as Carter, he believes she is wiser.

McKay also occasionally displayed some acting skills; he successfully fooled Richard Woolsey, but not Jack O'Neill, mostly due to his recognizing something McKay was doing as being faked after years of working with Carter.

Hypochondria
"I'm no Ronon – I'm not gonna be on the cover of “Shape” magazine any time soon... but I can handle myself in combat; stand my ground when I need to."

- Rodney Mckay

McKay is a renowned hypochondriac, claiming at various times to suffer from hypoglycemia, restless leg syndrome, allergies to bee stings and citrus fruit, among other things. He once said that he had studied medical science at one time, but stopped, because the amount of information on the human body made him start to diagnose himself with many phantom diseases. He has an obsession with protecting his skin, which lead him to invent SPF 100 factor sun block while on a mission to P3M-736, a planet with no ozone layer.

Because of his hypoglycemia, he eats regularly. After three years, the rest of the team notices that eats too much. However, McKay claimed that he weighed exactly the same as he had three years earlier. He also enjoys eating Meals ready to eat, hospital food, and airline food (though his only complaint being that he can't get seconds). While he and Sheppard were playing what they thought was an Ancient game, McKay inadvertently forced the people of Geldar to despise anything citrus and made them believe that "even the sunlight is dangerous".

Relationships and friendships
"Nope, that's pretty much it—petty, arrogant, bad with people."

- Samantha Carter

McKay is very awkward when it comes to relationships with women. However, he still claimed to have dated several women at least twice during his education years, in particular, someone named Teresa Geldar on two occasions and Jocelyn Rutger once. He also had a fondness for his neighbor, who hates him, but likes his cat, and claimed to have seen Kate Heightmeyer temporarily. He also has a predilection for women with short blonde hair, particularly Col. Carter. He named the people of Geldar after a blonde girl he once dated; and went so far as advising their women to wear their hair in a manner similar to Col. Carter's.

During his time with the SGC and the Expedition, he had three major relationships with women over recent years, as well as friendships within his team.

Samantha Carter
"This is why I could never have a relationship with you, Rodney. You don't listen to people—you don't trust them." "I have every reason not to. <…> You want something done right, do it yourself."

- Samantha Carter and McKay

Since McKay has a fondness for women with short blonde hair, he had fallen for Samantha Carter, and wasn't afraid to show it. However, Carter did not requite his feelings, due to his arrogance. However, since his attitude has improved over the years, but they only went as far as to become friends. In 2007, McKay learned that Carter would become the new Atlantis leader after Weir's MIA. McKay confronted her and warns her of "the unrequited lust that's been hanging over our heads for what seems like forever."

Katie Brown
"You have a date, Rodney? With a woman?"

- Carson Beckett

One of his first solid relationships during his time in the Atlantis Expedition was Katie Brown, a botanist who came to Atlantis in the Expedition's second year of operation. Things started awkward between the two of them, particularly when Laura Cadman's mind went into McKay's body. After the situation where Cadman made McKay kiss her, he started to avoid her for the following year. However, McKay later found time to see her, and their relationship went into full swing. In 2008, he planned to marry her, but after a quarantine lockdown, he discovered that he was not ready for that. However, Brown took that as a sign of breaking up, and left for Earth.

Jennifer Keller
"I've loved you for some time now."

- Rodney McKay, later repeated by Keller

After learning that Brown broke up with him, he later revealed to have feelings for Jennifer Keller. She once invited him for a drink after he was stuck with Carter in an underground Genii mine on M5V-801. Later, six days since he was infected with Second Childhood, he told Keller that he loved her. Later, McKay discovered that Ronon had also fallen for Keller. He told Ronon that he wouldn't fight for her, but wouldn't back down either. Instead, they both agreed on letting the best man win. After Ronon's repeated attempts and apparent success at winning over Keller told Ronon that she was interested in someone else, which turned out to be McKay, after she went on a date with him on their visit back to Earth. McKay and Keller shared a romantic moment when Rodney saved her after she was trapped in a freezing, wet room, where he confessed that he wouldn't know what to do if she died. They spent their time flying back to Stargate Command kissing in a private jet. The two were shown holding each other as Atlantis floated outside San Francisco Bay, both happy to have their health and each other.

Atlantis Team
"Because Colonel Sheppard would have already had hours to try to make it back through the portal in the time I wasted explaining the situation to Conan and Xena!"

- Rodney McKay

Despite his abrasive attitude, McKay has, on many occasions, demonstrated a close bond with his fellow teammates on AR-1. Although he admitted that he never really bonded with Lieutenant Aiden Ford during his first year in Atlantis, he and John Sheppard have shown on many occasions that they have a great esteem for the others' abilities. His relationships with Teyla Emmagan and Ronon Dex were not as close as his friendship with Sheppard, but McKay nevertheless clearly values his relationships with them.

John Sheppard
"You're a good friend, Arthur."

- Rodney McKay

McKay commonly attempted to help John when he suffered from personal problems despite his own poor abilities with relationships, such as when he attempted to express his sympathies following the death of Sheppard's father. The two have also been shown to spend a surprising amount of their leisure time together; both of them playing what they initially believed to be a Sims-like game before learning that it was an Ancient experiment with real people, and racing RC cars in the lower halls of Atlantis. After a game of virtual golf, John was the first person McKay notified of his intention to marry Katie Brown. In an alternate future, McKay spent 25 years working on a way to get Sheppard home from the future and succeeds.

Ronon Dex
"...he saved my life. He's like a brother to me."

- Rodney McKay

When Ronon was briefly recaptured by the Wraith, McKay defended his strong desire to find Ronon by stating that they had a very close bond despite the lack of social time they spent together, claiming that he sees Ronon as a brother (Albeit a brother who got all the genes that he didn't). After McKay was dying after using the Ascension machine, he used his powers to remove all the scars from Ronon's back. Although less demonstrative about it, Ronon has indicated that he reciprocates this bond, stating that he was willing to take the risk of taking McKay to the Shrine of Talus when McKay suffered from Second Childhood just to give McKay one more day as himself. During the alliance with Michael's hive one of the Wraith attendants made an innocent act of leading McKay by the shoulder to which Ronon violently defended McKay and nearly killed the Wraith on the spot stating "Touch him again and you die!" He and Ronon also agreed to simply let the best man win when they both learned that the other was attracted to Jennifer Keller.

Teyla Emmagan
"No-no-no-no-no. I know exactly what to do. You are the one who's lost a loved one. I will serve you."

- Rodney McKay

While he has been less vocal about his relationship with Teyla, McKay was the only person present when Teyla gave birth to her son, creating a particular bond between them (Although he was somewhat disappointed when she didn't name her son after him). She does however, on occasion, allow him to hold Torren for a while. After using the ascension machine, he took time in learning the Athosian tradition where they have ceremonial tea for the anniversary of the death of her father. She, along with the rest of the team, risked their lives to go to the shrine of Talus, in order to give McKay one last day as himself after he became infected with the Second Childhood.

Carson Beckett
"You were the closest thing to a best friend I ever had."

- Rodney McKay

At first he had a somewhat antagonistic relationship with Beckett, but the two became friends over time, with McKay admitting at one point that Beckett was the closest thing he had to a best friend. The two planned to go fishing at one point, but McKay ditched Beckett. This was something he came to greatly regret as Beckett was killed later that day. He was extremely upset by his death and was later comforted by a vision of him. McKay was one of his pallbearers returning his coffin to Earth, and later told Beckett's mother of her son's death himself. When Beckett returned as a clone, McKay was willing to trust him immediately and was the one to inform him of the events. When he was placed into stasis, it was hard on him, and apparently spent a lot of time keeping Beckett's frozen figure updated on current events, although he always denied it. McKay and Beckett worked together to escape a Wraith hive ship and McKay was at first a bit hurt that Beckett couldn't spend a little time catching up with him, but Beckett ultimately made time for him despite having a busy schedule.

Jeannie Miller
"I really do wish you the best, you know, and I'm sorry we weren't closer."

- Rodney McKay

McKay had a bad relationship with his sister for many years. After she left college to start a family, he dropped out of contact with her for four years until he was brought in to try to convince her to help. Before that, however, when everyone thought they would die from a Wraith invasion, McKay recorded a personal message to her, saying he regretted how their relationship was and hoped that if he survived, they could be closer in the future. For some reason, Jeannie never got the message until she visited Atlantis in 2006. When the two finally worked together, McKay seemed to mostly ignore her. When an alternate version of himself showed up, McKay feared she liked him better and realized how bad of a brother he'd been to her with the help of Sheppard. Sheppard showed her the recording, which seemed to affect her opinion of him for the better, making her comment that now she'd seen three sides of McKay. The two seemed to semi-reconcile afterward with McKay promising to visit whenever he could.

In 2007, he sent her messages, trying to get her help with nanite coding. After she was injected with nanites that would ultimately kill her if not shut down, McKay used everything he could to convince "Todd" to help, and was even willing to sacrifice himself to feed to "Todd" to save her. He later bought her a Prius as part of a guilt-trip present. When he was infected with the Second Childhood, Jeannie was brought in and was clearly moved by his condition. It was very hard for her to see him in the condition he was in and actually had to leave the room as she didn't want him to see her crying. Despite having lost a lot of memories and being regressed to a childlike state, McKay recognized her. Jeannie ended up risking her life along with the rest of his team to give him one more day as himself so he could die with honor.

Behind the scenes

 * McKay was originally going to be replaced by a scientist named Dr. Ingram, until the Stargate Atlantis production team contacted David Hewlett to reprise his role as McKay.
 * Contrary to popular belief, according to an interview on the Second season DVD box set, Hewlett is not allergic to citrus; he demonstrated by eating a lemon.
 * Rodney McKay and John Sheppard are the only two Stargate Atlantis characters to appear in every episode of the series.
 * The actress who plays his sister is actually David Hewlett's real life sister.