Mireille Messier

Mireille Messier (born March 19, 1971) is a Canadian writer of children's literature, who has published work in both English and French. She is most noted for her 2016 book The Branch, which was a shortlisted Governor General's Literary Award finalist for English language children's illustration at the 2016 Governor General's Awards, and her 2023 book The Magic Cap (Le bonnet magique), which won the Trillium Book Award for French children's literature in 2025.

Born in Montreal, Quebec, and raised in Ottawa, Ontario, she worked in radio in her early career, including stints as director of French programming at CHUO-FM in Ottawa, and as a radio host on CHOD-FM in Cornwall. She moved to Toronto in 1995, working for TFO as a researcher and reporter for programs such as Panorama and Méga TFO, before publishing her first children's book in 1999.

She has written and published both illustrated picture books for young children and a series of short novels for middle grade readers which centre on Viviane and Simon, young amateur detectives who travel around Ontario solving local mysteries.