Phil O'Brien may refer to:
Sportsmen Phil O'Brien (footballer) (1930–2020), Australian rules forward Phil O'Brien (motorcyclist), Australian racer in 1969 Grand Prix motorcycle racing season, 500cc race Phil O'Brien (athlete), English runner in 1983 IAAF World Cross Country Championships – Senior men's race
Writers Phil O'Brien, pen name, since 1970s, of Irish dramaturge Philomena Muinzer Phil O'Brien, American journalist, 1993–94 president of New York Press Club Phil O'Brien, Australian writer, musician and filmmaker who directed 2022 film in Nhulunbuy, Northern Territory
Others Phil O'Brien, New Zealand presenter on TVNZ and Radio New Zealand since 1970s Phil O'Brien (entrepreneur), British photographer, founder of EMPICS in 1985