(born August 15, 1956) is a French-Canadian jazz pianist and composer.

She studied with Armas Maiste at McGill University in 1978 and 1979, and later took lessons from Kenny Barron in New York.

Desmarais has recorded ten albums as a solo performer and musical director, including several with well-known artists such as Michel Cusson and Michel Donato (Vision), Tiger Okoshi (Lorraine Desmarais), Don Alias (Andiamo), André Moisan, Jean Gaudreault and Ted Baskin from the Montreal Symphony Orchestra and Michel Bettez from the Orchestre Métropolitain (Bleu Silence), in addition to her long-standing team of Frédéric Alarie (double bass) and Camil Bélisle (drums).

She has composed a number of pieces for herself and for other performers, including Oliver Jones and Angèle Dubeau.

[1] She has been teaching in colleges and universities since 1985, and is a jazz piano professor at the Cégep Saint-Laurent in Montreal.