John O'Brien may refer to: Public officials. American. John O'Brien (Ohio politician) (1932–1985), former member of the Ohio House of Representatives. John D. O'Brien, state senator in the 1997–1998 Massachusetts legislature. John F. O'Brien (secretary of state) (c. 1850–1927), Secretary of State of New York, 1903–1906. John F. O'Brien (judge) (1874–1939), New York Court of Appeals judge. John H. O'Brien, 4th Fire Commissioner of the City of New York. John J. O'Brien (civil servant) (1919–2001), investigated the assassination of President John F. Kennedy. John J.
https://en.wikipedia.org/wiki/John_O%27Brien