Linda was born in Salisbury, Maryland in 1956. Her father was a doctor, and he was killed in a car accident. She has an identical twin sister Leslie Hamilton Gearren, and another sister Laura and a brother, John.
After attending Wicomico High School, Linda studied for two years at Washington College in Chestertown, Maryland, before moving on to acting studies in New York. Here, she attended acting workshops given by Lee Strasberg. She started working in TV, with a role in Beauty and the Beast, but she became internationally famous for her performance as Sarah Connor in Terminator and Terminator 2: Judgement Day.
Linda was married to Bruce Abbott from December 19, 1982 to 1989; they have one son, Dalton Bruce (b. October 4, 1989). Her second husband was the director James Cameron from July 26, 1997 to 1999; they have one daughter, Josephine Archer (b. February 15, 1993).