Denny Doherty was born and reared in Halifax, Nova Scotia, Canada and began his musical career there in a local rock band, The Hepsters, while working in a pawn shop. He had started singing in public at age 15 on a dare by performing in a skating rink-turned-dance-hall. In 1959 he formed his first folk trio, The Colonials, and after changing their name to The Halifax Three, signed a recording contract in New York. After recording two albums, the trio broke up, and Denny linked with Cass Elliot as a member of her group, The Big Three, which later became The Mugwumps, the first folk-rock group. Cass and Denny later joined John and Michelle Phillips of The New Journeymen to become The Mamas and The Papas. In 1965 the group relocated to Los Angeles where, over the next four years, they turned out a score of top-selling albums and singles featuring Doherty and Elliot's lead vocals. Upon the collapse of the group, Denny recorded two solo albums, and material for an unreleased third. Denny was inducted into the Canadian Music Hall of Fame in 1996; The Mamas and The Papas were inducted into the Rock and Roll Hall of Fame in 1998, and the Vocal Group Hall of Fame in 2001.
Doherty was married briefly to Linda Woodward in the early seventies with whom he had a daughter, Jessica. He lived outside Toronto with his other two children, Emberly and John, to whose mother Jeannette, Doherty was married for twenty years until her death in 1998. He died on January 19, 2007, following kidney problems.