Michael O'Brien

Michael or Mike O'Brien may refer to:

• Michael O'Brien (South Australian politician) (born 1949), Australian Labor Party member of the South Australian House of Assembly, 2002–present
• Michael O'Brien (Victorian politician) (born 1971), Liberal Party of Australia member of the Victorian Legislative Assembly, 2006–present
• Mike O'Brien (British politician) (born 1954), United Kingdom Labour Party politician
• Michael H. O'Brien (born 1954), Member of the Pennsylvania House of Representatives, 2007–present
• Michael O'Brien (Ohio politician) (born 1955), member of the Ohio House of Representatives
• Mike O'Brien (Michigan politician), Michigan Congressional Candidate
• Mike O'Brien (Seattle politician) (born 1968), Seattle City Council member
• Michael O'Brien (Fianna Fáil politician), Irish former councillor and mayor of Clonmel
• Mike O'Brien (Canadian politician), mayor of Fredericton, New Brunswick
• Michael O'Brien, former Portfolio Holder for Children's Services and Councillor at Medway Council

• Michael O'Brien (Australian rules footballer) (born 1980), West Coast Eagles
• Michael O'Brien (fencer) (born 1969), Irish fencer
• Michael O'Brien (swimmer) (born 1965), American swimmer
• Michael O'Brien, first known streaker at a major sporting event
• Michael O'Brien (Irish sportsman), Irish association footballer, Gaelic footballer and cricketer in the 1920s
• Mike O'Brien (hurler) (born 1978), Irish hurler
• Michael O'Brien (hurling manager) (1922–2012), Irish Catholic priest and former hurling manager
• Micheál O'Brien (1923–2015), Irish Gaelic footballer and hurler

• Michael O'Brien (American poet) (born 1939), American poet
• Michael O'Brien (game designer), Australian game designer
• Mike O'Brien (game developer), co-founder, ArenaNet; game designer and programmer
• Michael O'Brien (photographer) (born 1950), American photographer
• Michael O'Brien (Canadian author) (born 1948), Canadian author
• Michael O'Brien (historian), American historian
• Mike O'Brien (actor), American writer and performer on Saturday Night Live
• Michael O'Brien (musician) (born 1964), American musician

• Guardsman (Michael O'Brien), a fictional character in the Iron Man comics
• Michael O'Brien, a fictional engineer character in the 1940 Christmas film Beyond Tomorrow (film)