John Ephraim Sibbit (Jack Sibbit) (4 March 1895 – 5 August 1950) was a British track cyclist who won a silver medal at the 1928 Summer Olympics. By age 41 he had held twelve national titles including tandem sprints, with Dennis Horn. Sibbit built, rode and sold his own 'Jack E Sibbit' bicycles from premises at 475 Stockport Road, Manchester.