Bibi Andersson was born as Berit Elisabeth Andersson on 11 November 1935 in Kungsholmen, Stockholm, the daughter of Karin (née Mansion), a social worker, and Josef Andersson, a businessman.
She has been married (1960, divorced) to the director Kjell Grede with whom she has a daughter, Jenny, and, secondly (1978, divorced), to the politician and writer Per Ahlmark. Since 29 May 2004, Andersson has been married to Gabriel Mora Baeza.
She studied acting at the Terserus Drama School and at the legendary Royal Dramatic Theatre School in Stockholm.
After completing school, she agreed to join the Royal Dramatic Theatre in Stockholm, which she was associated with for 30 years. Her first collaboration with Ingmar Bergman was in 1951, when she participated in his production of an advertisement for the detergent "Bris". In the 1950s, 60s and 70s, she starred in more than ten Bergman-directed pictures, including The Seventh Seal, Wild Strawberries, Brink of Life, The Magician and Persona.
In 1996, she published her autobiography Ett ögonblick (A Moment, or, literally, A Blink of the Eye).