Dorval was born in Noranda, Quebec, the daughter of Madeleine (Larouche) and Gaetan Dorval. She received her education at Cégep de Trois-Rivières and the Drama Conservatory of Montreal, beginning her career on the stage in 1984.
2010
In 2010, at the Palm Springs International Film Festival, she won the FIPRESCI Award for Best Actress for her performance in I Killed My Mother (J'ai tué ma mère) directed by Xavier Dolan.