Born in Weyburn in April 1934, Douglas is the daughter of Irma and T.C. Douglas, former Saskatchewan Premier. She attended the Banff School of Fine Arts, then studied at the Royal Academy of Dramatic Art in London, and acted in British television and theatre. She returned to Canada in 1957, married, and had her first child. She remarried, to actor Donald Sutherland, and had twins. Douglas has had a lifelong commitment to social activism. Having moved with her family to California in the late 1960s, she became involved in protest movements, first opposing the Vietnam War and then focusing upon the oppression of immigrants and women. She was later refused a work permit because of protest activities, so after her divorce from Sutherland she returned to Canada in 1977. Douglas continued to develop her acting career after her return to Canada. She is also a national spokesperson for the Canadian Health Coalition, an organization dedicated to preserving public health care. She has received numerous awards, including membership in the Order of Canada (2003).