Candidates (O)

Edward J. O’Beirne

• 1922 – Illinois’ 11th congressional district (D) – lost
• 1926 – Illinois’ 11th congressional district (D) – lost

John Lord O’Brian

• 1938 – United States Senate (New York) (R, Ind. Prog.) – lost

Benjamin E. O’Brien

• 1944 – Colorado’s 2nd congressional district (I) – lost
• 1946 – Colorado’s 2nd congressional district (I) – lost

Buck O’Brien

• 1986 – Montana’s 2nd congressional district (D) – lost
• 1988 – Montana’s 2nd congressional district (D) – lost

Charles Francis Xavier O’Brien

• 1920 – New Jersey’s 12th congressional district (D) – won
• 1922 – New Jersey’s 12th congressional district (D) – won

Cornelius O’Brien

• 1944 – United States Senate (Indiana) (Special) (D) – lost

Dave O’Brien

• 1988 – Iowa’s 6th congressional district (D) – lost

David V. O’Brien

• 1968 – New York’s 34th congressional district (R) – lost

Donald Eugene O’Brien

• 1958 – Iowa’s 8th congressional district (D) – lost
• 1960 – Iowa’s 8th congressional district (D) – lost

Dorothy G. O’Brien

• 1958 – Illinois’ 15th congressional district (D) – lost
• 1960 – Illinois’ 15th congressional district (D) – lost

E. Thomas O’Brien

• 1942 – Minnesota’s 6th congressional district (D) – lost

Edward J. O’Brien

• 2000 – Pennsylvania’s 15th congressional district (D) – lost
• 2002 – Pennsylvania’s 15th congressional district (D) – lost

Frank M. O’Brien

• 1932 – Pennsylvania’s 3rd congressional district (D) – lost

Frank O’Brien

• 1942 – Minnesota’s 6th congressional district (I) – lost

Frank T. O’Brien

• 1946 – Texas’ 18th congressional district (R) – lost

George Donoghue O’Brien

• 1936 – Michigan’s 13th congressional district (D) – won
• 1938 – Michigan’s 13th congressional district (D) – lost
• 1940 – Michigan’s 13th congressional district (D) – won
• 1942 – Michigan’s 13th congressional district (D) – won
• 1944 – Michigan’s 13th congressional district (D) – won
• 1946 – Michigan’s 13th congressional district (D) – lost
• 1948 – Michigan’s 13th congressional district (D) – won
• 1950 – Michigan’s 13th congressional district (D) – won
• 1952 – Michigan’s 13th congressional district (D) – won

George L. O’Brien

• 1992 – California’s 12th congressional district (L) – lost

George Miller O’Brien

• 1972 – Illinois’ 17th congressional district (R) – won
• 1974 – Illinois’ 17th congressional district (R) – won
• 1976 – Illinois’ 17th congressional district (R) – won
• 1978 – Illinois’ 17th congressional district (R) – won
• 1980 – Illinois’ 17th congressional district (R) – won
• 1982 – Illinois’ 4th congressional district (R) – won
• 1984 – Illinois’ 4th congressional district (R) – won

Harry J. O’Brien

• 1942 – Minnesota’s 6th congressional district (I) – lost
• 1944 – Minnesota’s 6th congressional district (DFL) – lost

Harry O’Brien

• 1950 – United States Senate (North Dakota) (D) – lost

J. W. ‘Billy’ O’Brien

• 1976 – Virginia’s 4th congressional district (D) – lost

James P. O’Brien

• 1958 – Pennsylvania’s 24th congressional district (D) – lost

John A. O’Brien

• 1964 – Pennsylvania’s 9th congressional district (D) – lost

John H. O’Brien

• 1976 – New Hampshire’s 1st congressional district (L) – lost

Joseph John O’Brien

• 1938 – New York’s 38th congressional district (R) – won
• 1940 – New York’s 38th congressional district (R) – won
• 1942 – New York’s 38th congressional district (R) – won
• 1944 – New York’s 40th congressional district (R) – lost

Joseph O’Brien

• 1968 – Rhode Island’s 1st congressional district (I) – lost

Leo William O’Brien

• 1952 – New York’s 30th congressional district (D, Liberal) – won
• 1954 – New York’s 30th congressional district (D, Liberal) – won
• 1956 – New York’s 30th congressional district (D, Liberal) – won
• 1958 – New York’s 30th congressional district (D, Liberal) – won
• 1960 – New York’s 30th congressional district (D) – won
• 1962 – New York’s 29th congressional district (D, Liberal) – won
• 1964 – New York’s 29th congressional district (D, Liberal) – won

Loren N. O’Brien

• 1930 – Michigan’s 9th congressional district (D) – lost

Michael P. O’Brien

• 2005 – California’s 5th congressional district (Special) (R) – lost

Michael P. O’Brien

• 1952 – Ohio’s 23rd congressional district (D) – lost

Mike O’Brien

• 2012 – Michigan’s 6th congressional district (D) – lost

N. W. O’Brien

• 2004 – Florida’s 6th congressional district (W/I) – lost

Newell O’Brien

• 1996 – Florida’s 6th congressional district (D) – lost

Patrick H. O’Brien

• 1930 – Michigan’s 6th congressional district (D) – lost

Richard A. O’Brien

• 1920 – Maryland’s 2nd congressional district (Labor) – lost
• 1922 – Maryland’s 2nd congressional district (Labor) – lost

Thomas C. O’Brien

• 1936 – United States Senate (Massachusetts) (I) – lost

Thomas Joseph O’Brien

• 1932 – Illinois’ 6th congressional district (D) – won
• 1934 – Illinois’ 6th congressional district (D) – won
• 1936 – Illinois’ 6th congressional district (D) – won
• 1942 – Illinois’ 6th congressional district (D) – won
• 1944 – Illinois’ 6th congressional district (D) – won
• 1946 – Illinois’ 6th congressional district (D) – won
• 1948 – Illinois’ 6th congressional district (D) – won
• 1950 – Illinois’ 6th congressional district (D) – won
• 1952 – Illinois’ 6th congressional district (D) – won
• 1954 – Illinois’ 6th congressional district (D) – won
• 1956 – Illinois’ 6th congressional district (D) – won
• 1958 – Illinois’ 6th congressional district (D) – won
• 1960 – Illinois’ 6th congressional district (D) – won
• 1962 – Illinois’ 6th congressional district (D) – won

Timothy J. O’Brien (Michigan)

• 1984 – Michigan’s 18th congressional district (L) – lost
• 1988 – Michigan’s 18th congressional district (L) – lost

W. A. O’Brien

• 1922 – New Jersey’s 12th congressional district (R) – lost

Walter A. O’Brien, Jr.

• 1948 – Massachusetts’ 10th congressional district (D) – lost

William H. O’Brien

• 1920 – Massachusetts’ 12th congressional district (‘The People’s Candidate’) – lost

William J. O’Brien

• 1988 – Pennsylvania’s 1st congressional district (R) – lost

William S. O’Brien

• 1926 – West Virginia’s 3rd congressional district (D) – won
• 1928 – West Virginia’s 3rd congressional district (D) – lost

E. Thomas O’Brien

• 1940 – Minnesota’s 6th congressional district (D) – lost

Joseph J. O’Brocta

• 1936 – New York’s 43rd congressional district (S) – lost

Henri O’Bryant, Jr.

• 1966 – California’s 30th congressional district (R) – lost

Jeremiah J. O’Callaghan

• 1954 – New Jersey’s 13th congressional district (I) – lost
• 1968 – New Jersey’s 13th congressional district (Voice of Independence) – lost

Jerry A. O’Callaghan

• 1956 – Wyoming’s at large congressional district (D) – lost

L. J. (Jim) O’Callaghan

• 1962 – Georgia’s 5th congressional district (R) – lost
• 1964 – Georgia’s 5th congressional district (R) – lost

Thomas P. O’Callaghan

• 1960 – New York’s 19th congressional district (R) – lost