American-born Canadian author known for her autobiographical novels, short stories, and radio plays.

Thomas graduated from Smith College, Northampton, Massachusetts, in 1957 and settled in Canada in 1959. After receiving an M.A. from the University of British Columbia in 1963, she lived in Ghana from 1964 to 1966 and then returned to British Columbia, where she divided her time between Vancouver and Galiano Island.

Thomas wrote about domestic life, women's search for independence, and conflicts between men and women. She often threw her characters' inner conflicts into relief by transplanting them to foreign lands. Thomas's experimental style involved incorporating into her works wordplay and fragments of popular culture, including cartoons, nursery rhymes, and advertisements.

The stories of Ten Green Bottles (1967) are told by an unhappy female narrator of varying circumstances but consistent character. Thomas's alter ego Isobel Cleary narrates the novels Mrs. Blood (1970), Songs My Mother Taught Me (1973), based on Thomas's childhood memories, and Blown Figures (1974), set in Ghana and using Africa as a metaphor for the unconscious. The novels Latakia (1979) and Intertidal Life (1984) both concern a woman writer adjusting to the end of a romantic relationship. Her later works include the story collections Goodbye Harold, Good Luck (1986) and The Wild Blue Yonder (1990) and the novels Graven Images (1993) and Coming Down from Wa (1995), about a young art history student's spiritual journey to West Africa.