Patrick O'Brien
Patrick O'Brien may refer to:
- Patrick Cotter O'Brien, the tallest person alive in his lifetime
- Patrick O'Brien (Australian politician), politician in Victoria, Australia
- Sir Patrick O'Brien, 2nd Baronet, Irish politician
- Patrick Joseph O'Brien, Member of Parliament for North Tipperary, 1885–1906
- Pat O'Brien (Irish politician), Irish Nationalist MP in the United Kingdom Parliament
- Patrick O'Brien (footballer, born 1875), Scottish footballer
- Patrick O'Brien (footballer, born 1884), Scottish footballer and surgeon
- Patrick O'Brian, English novelist and translator
- Patrick K. O'Brien, British academic and historian
- Patrick O'Brien (political scientist), politics professor, University of Western Australia
- Patrick O'Brien (musician), American musician and lutenist
- Patrick Thomas O'Brien, American actor
- Patrick O'Brien (artist), illustrator and author of children's books