Lois Patrice Griffin (née Pewterschmidt) is the wife of Peter Griffin and mother of Meg, Chris and Stewie Griffin. Lois lives at 31 Spooner Street with her family and also Brian, the anthropomorphic family dog.Lois is voiced by Alex Borstein. At the time series creator Seth MacFarlane approached her for a role on the show, she was doing a live stage show in Los Angeles, playing a redhead mother in a sketch. The voice style was modeled after one of her cousins' voice.

Born Lois Pewterschmidt, she was brought up in an extremely wealthy household with her sister, Carol. They also have a long-lost older brother, Patrick, who was sent to a mental asylum after he became a serial killer. She met Peter when he was employed as a towel boy by her aunt. Her rich father, Carter Pewterschmidt, cannot stand Peter and makes rude comments at every chance he gets. Peter seems to unintentionally do his absolute best to be a thorn in her side. Lois is currently a full-time-mom who, in the early years, also taught piano on the side.