Meredith Rodney McKay's father was a male Tau'ri, the husband of Meredith Rodney McKay's mother, the father of Dr. Rodney McKay and Jean Miller, and the maternal grandfather of Madison Miller.
Biography
Background information
He and his wife constantly argued during their son's childhood and blamed Rodney for it. They eventually divorced. (SG1: "Redemption, Part 2")
2004
In 2004, Rodney told Dr. Carson Beckett and Lt. Aiden Ford that his sister was the only family that he really had, implying that both of his parents had died by then. (SGA: "Hot Zone")
When Rodney was young, he refused to pay for a license for Rodney's dog, so the animal shelter could not track it when it ran away. (SGA: "Letters from Pegasus")
2006
In 2006, Rodney mentions to Jeannie that their father would've wanted them to be working together. (SGA: "McKay and Mrs. Miller")
2007
In 2007, Rodney told Dr. Radek Zelenka that his sister was afraid of the dark and used to leave lights in every room of their house, which drove their father crazy. She would blame Rodney for leaving the lights on and he would believe her. He never sided with him. (SGA: "Tao of Rodney")