Macha Grenon is a Canadian film and television actress.
Her credits include roles in the television series Urban Angel, Scoop, Le cœur a ses raisons, Emily of New Moon and H₂O, as well as the films The Pianist, Stardom, Familia, Windsor Protocol, You Can Thank Me Later, L'Âge des ténèbres, Barney's Version and The Year Dolly Parton Was My Mom. She garnered a Best Actress nomination at the 26th Genie Awards for her performance in Familia.
She is the partner of film director Denis Villeneuve. Her father, Michel Grenon, was a history professor at the Université du Québec à Montréal, and her grandfather, Hector Grenon, was a historian who wrote several books on the history of Montreal.