Keith Sinclair (born 26 June 1945) is a British field hockey player who competed at the 1968 Summer Olympics and the 1972 Summer Olympics.
Sinclair studied at the University of Manchester and played club hockey for Tulse Hill and represented Cheshire at county level.
While with Tulse Hill he represented the England U23 team, Great Britain at the 1968 Olympic Games in Mexico City and the Great Britain team again at the 1972 Olympic Games in Munich.