John Sinklo (also Sinclo, Sincklo, Sincler, Sinkler, Sinclair) was an English Renaissance theatre actor, known to be active between 1592 and 1604. He was a member of several playing companies, including Lord Strange's Men, Pembroke's Men, Lord Chamberlain's Men and the King's Men. It is likely that Sinklo also performed with Sussex's Men, following the text of Titus Andronicus which Sussex's inherited from Pembroke's.