Judith Doris Forst, OC, OBC (born November 7, 1943) is a Canadian mezzo-soprano.
Born in New Westminster, British Columbia, she received a Bachelor of Music from the University of British Columbia in 1964. She is the sister-in-law of long time Vancouver radio personality Brian (Frosty) Forst. In 1968 she won the Metropolitan Opera National Council Auditions.
Forst made her debut at the Metropolitan Opera on September 19, 1968 at the age of 24 in the small role of the Page in Rigoletto. Other Met roles include (in chronological order) Tebaldo in Verdi's Don Carlo, Stéphano in Gounod's Roméo et Juliette, Mercédès in Bizet's Carmen, Teresa in Bellini's La sonnambula, Siebel in Gounod's Faust, Kate Pinkerton in Puccini's Madama Butterfly, Lola in Mascagni's Cavalleria rusticana, Bersi in Umberto Giordano's Andrea Chénier, Estrella in Offenbach's La Périchole, Preziosilla in La forza del destino, Hänsel in Hänsel und Gretel, Flora in La traviata, Giulietta in Les contes d'Hoffman, Donna Elvira in Don Giovanni, Mère Marie in Poulenc's Dialogues of the Carmelites, Kabanicha in Janáček's Káťa Kabanová, Adelaide in Arabella, The Witch in Hänsel und Gretel, and Kostelnicka in Jenůfa.
In 1991, she was made an Officer of the Order of Canada. In 2001, she was awarded the Order of British Columbia.
In 2011, she will create the role of Pauline Johnson in the first chamber opera written by Margaret Atwood, with music by Christos Hatzis, Pauline. It is set in Vancouver in March 1913, in the last week in the life of the celebrated and eponymous Canadian literary figure. Pauline will be produced by City Opera Vancouver, with a generous commissioning grant from the Canada Council, and assistance from Tom Lee Music and Steinway & Sons.