|Notable works||Reading by Lightning, Curiosity, The Opening Sky, Five Wives|
Thomas grew up in Carberry, Manitoba and later worked as a freelance journalist and book reviewer for The Globe and Mail, the Winnipeg Free Press and Prairie Fire, and as a book editor for Turnstone Press. She won a National Magazine Award in 1996 for her journalism.
Her second novel, Curiosity, was nominated for the Scotiabank Giller Prize, the Margaret Laurence Award for Fiction, and the McNally Robinson Book of the Year Award. Both novels were longlisted for the International Dublin Literary Award.
Her third novel The Opening Sky (2014) was shortlisted for the Governor General's Award for English-language fiction, the Carol Shields Book Award, and the Margaret Laurence Award for Fiction. It won the McNally Robinson Book of the Year Award, and was named a CBC book of the year.
- Reading by Lightning, 2008 (Goose Lane Editions, ISBN 978-0-86492-512-1)
- Curiosity, 2010 (McClelland & Stewart, ISBN 978-0-7710-8417-1)
- The Opening Sky, 2014 (McClelland & Stewart, ISBN 978-0-7710-8392-1)
- Five Wives, 2019 (HarperCollins, ISBN 978-1443458542)
- "Thomas, Joan (Sandra Joan)". Manitoba Archival Information Network. Retrieved January 22, 2022.
- "Somewhere in the memory of the universe" in Prairie Fire vol. 16 no. 3. Autumn, 1995.
- "Western Canadian writers capture Commonwealth book awards". cbc.ca, March 12, 2009.
- "Thomas wins Amazon First Novel Award". The Globe and Mail, September 25, 2009.
- "Miriam Toews wins $25,000 Writers’ Trust Fiction Prize". Toronto Star, November 4, 2014.
- Jane van Koeverden, "Here are the winners of the 2019 Governor General's Literary Awards". CBC Books, October 29, 2019.