The youngest of five children, Gail Fisher was born in Orange, New Jersey. Her father died when she was two years old and she was raised by her mother, Ona Fisher, who raised her family with a home operated hair styling business while living in the Potter’s Crossing neighborhood of Edison, New Jersey. She graduated from Metuchen High School in Metuchen, New Jersey. During her teenage years she was a cheerleader and entered several beauty contests, winning the titles of Miss Transit, Miss Black New Jersey, and Miss Press Photographer. In a contest sponsored by Coca-Cola, Gail Fisher won the opportunity to spend two years studying acting at the American Academy of Dramatic Arts. As a student of acting in New York City, she worked with Lee Strasberg  and became a member of the Repertory Theater at Lincoln Center, where she worked with Elia Kazan and Herbert Blau. As a young woman, she also worked as a model. Fisher made her first television appearance in 1960 at age 25, appearing in the syndicated program Play of the Week. Also during the early 1960s, she appeared in a television commercial for All laundry detergent, which she said made her “the first black female — no, make that black, period — to make a national TV commercial, on camera, with lines.” In 1965 Herbert Blau cast her in a theatrical production of Danton’s Death. She first appeared in Mannix during the second season, when Mannix left the detective firm Intertect and set up shop as a private investigator. In 1968, she made guest appearances on the TV series My Three Sons, Love, American Style, and Room 222. In 1970, her work on Mannix was honored when she received the Emmy Award for outstanding performance by an actress in a dramatic supporting role. In winning the Emmy, she beat out Susan Saint James in The Name of the Game and Barbara Anderson in Ironside becoming the first black woman to win an Emmy Award. After Mannix was canceled in 1975 she rarely appeared on television. She guest-starred in a 1980 episode of The White Shadow.

Gail Fisher was married and divorced twice. She had two daughters, Samara and Jole, from her 1964 first marriage to John Levy. Her previous marriage to Wali Muhammad (Walter Youngblood), famed cornerman to Sugar Ray Robinson and Muhammad Ali, ended in divorce when he changed religions. Wali was also an assistant minister to Malcolm X at Nation of Islam Mosque No. 7. She died in Los Angeles in 2000, aged 65, reportedly from renal failure. Twelve hours after Gail Fisher died, her brother Clifton died from heart failure. Gail Fisher was cremated.