John Brenan may refer to: John Brenan (bishop) (died 1693), Irish Roman Catholic archbishop Ryan Brenan (John Ryan Brenan, 1798–1868), Australian politician John Brenan (physician) (1768–1830), Irish physician John Fitzgerald Brenan (1883–1953), British diplomat in China John Patrick Micklethwait Brenan (1917–1985), British botanist
See also John Brennan (disambiguation) Michael John Brenan (1780–1847), Roman Catholic priest and ecclesiastical historian