Marcus Haddock (born 19 June 1957) is an American opera singer and voice teacher who in the course of his 25-year stage career sang leading tenor roles throughout the United States and Europe.
Born in Fort Worth, Texas and trained at the Boston University College of Fine Arts under Phyllis Curtin, Haddock began his career in the United States after winning the Metropolitan Opera National Council Auditions in 1984.
Haddock made his European debut in 1986 as Ford in Salieri's Falstaff with Opéra National de Bordeaux and returned there the following year as Nemorino in L'elisir d'amore.
His Metropolitan Opera house debut came in 2003 when he sang the title role in Gounod's Faust and appeared there later that season as Alfredo in La traviata.
He was preparing to leave for a series of opera engagements in Europe in March of that year when he suffered two massive strokes in 24 hours at his home in Skaneateles, New York where he and wife Kathleen had settled in the late 1990s.