Gentleman John, Gentleman Johnny, or Gentleman Jonathan may refer to:
Gentleman John:
- Johnny Enzmann (1890–1984), American Major League Baseball pitcher
- John Harris (footballer) (1917–1988), Scottish footballer
- John Jackson (English boxer) (1769–1845), English boxer
- John Palmer (actor) (1742?–1798), English actor
- John L. Rotz (1934–2021), American jockey
- John Sattler (born 1942), Australian rugby league footballer of the 1960s and 1970s
Gentleman Johnny:
- John Burgoyne (1722–1792), British Army general in the American Revolutionary War
- Johnny Ramensky (1905–1972), Scottish career criminal and Second World War British Army commando
Gentleman Jonathan
- "Gentleman" Jonathan Sayers, a professional wrestling manager from All- Star Wrestling
Fictional characters:
- "Gentleman" Johnny Marcone; see List of The Dresden Files characters