John Barnhill may refer to:
John Barnhill (American football) (1903–1973), American football coach, college athletics administrator John Barnhill (basketball) (1938–2013), NBA and ABA player John Barnhill (politician) (1905–1971), assassinated Ulster Unionist Party member of the Senate of Northern Ireland
See also John Barnhill Dickie (1829–1886), Canadian farmer, teacher and politician