Born in Kirkcaldy, Scotland, the daughter of Archibald Wernham and Christina Noble, she received a Master of Arts degree in philosophy from University of Aberdeen in 1944. In 1949, Wilson emigrated to Canada with her husband, the Reverend John Wilson, whom she had married in 1945. They settled in Renfrew, Ontario where her husband became the United Church minister. Three years later, in 1952, her husband became a naval chaplain during the Korean War and she worked as a dental receptionist in Ottawa. In 1954, her husband was posted to Halifax, Nova Scotia and they both moved.
From 1991 to 1996, she was a Commissioner of the Royal Commission on Aboriginal Peoples. Bertha Wilson gave a controversial and much-discussed speech about the role and influence of women in legal professions and the judiciary titled “Will Women Judges Really Make a Difference?”