John Leighton Brecknock (29 November 1937 – 30 May 2017) was an English operatic tenor. He was born at Long Eaton, Derbyshire, joined the chorus of Sadler's Wells Opera in 1967 and graduated to small solo roles. He made his Covent Garden debut in 1974 as Fenton in Verdi's Falstaff with Tito Gobbi. In 1977 he co-starred at the Paris Opéra with Teresa Berganza in Rossini's La Cenerentola, and in 1978 sang Don Ottavio in Mozart's Don Giovanni at the Metropolitan Opera, New York, to the Donna Anna of Joan Sutherland, who wrote of his "beautiful glossy voice and easy technique". In London he performed at English National Opera, the Royal Opera and the Proms.