Pat O'Brien may refer to:
Politicians Pat O'Brien (Irish politician) (c. 1847–1917), Irish Nationalist MP in the United Kingdom Parliament Pat O'Brien (Canadian politician) (born 1948), member of the Canadian House of Commons Patrick Joseph O'Brien, (1835–1911) , Irish Nationalist MP in the United Kingdom Parliament
Others Benson Harrison "Pat" O'Brien (1894–1983) of Pat O'Brien's Bar, US cocktail maker Pat O'Brien (actor) (1899–1983), American film actor Maynard O'Brien (1907–1990), American football coach nicknamed Pat Pat O'Brien (radio and television personality) (born 1948), American sports commentator and television host Pat O'Brien (guitarist) (born 1965), American guitarist for Cannibal Corpse Pat O'Brien (racing driver) (born 1965), Hall of Fame modified racing driver Pat O'Brien (rugby union) (born 1989), South African rugby union player
See also Patrick O'Brien (disambiguation)