John Leslie Mitchinson (31 March 1932 – 17 December 2021) was an English operatic tenor.
He made his début singing the role of Jupiter in Handel's Semele.
In 1978 he joined the Welsh National Opera, with whom he worked for four years.
Able to sing a variety of roles, he portrayed Peter Grimes and Tristan during this period, among others.
He sang the title role of Wagner's Rienzi in a 1976 BBC broadcast of one of the rare performances in recent history of the complete opera; a recording of this broadcast survives and has circulated.