Candidates (O)

Daniel J. C. O’Donnell

• 1942 – Pennsylvania’s 10th congressional district (D) – lost

Daniel J. O’Donnell

• 1924 – Pennsylvania’s 5th congressional district (D) – lost
• 1926 – Pennsylvania’s 5th congressional district (D) – lost

James D. O’Donnell

• 2014 – New York’s 27th congressional district (D, CON) – lost
• 2018 – New York’s 18th congressional district (R, CON, Ref.) – lost

Justin O’Donnell

• 2018 – New Hampshire’s 2nd congressional district (L) – lost
• 2020 – United States Senate (New Hampshire) (L) – lost

P. M. O’Donnell

• 1922 – Pennsylvania’s 32nd congressional district (D) – lost
• 1924 – Pennsylvania’s 32nd congressional district (D) – lost

Pierce O’Donnell

• 1980 – California’s 22nd congressional district (D) – lost

Raymond O’Donnell

• 2012 – United States Senate (Michigan) (W/I) – lost

Rick O’Donnell

• 2006 – Colorado’s 7th congressional district (R) – lost

Robert J. O’Donnell

• 1924 – Ohio’s 2nd congressional district (D) – lost
• 1926 – Ohio’s 2nd congressional district (D) – lost

Shawn M. O’Donnell

• 2006 – Virginia’s 1st congressional district (D) – lost

Steve O’Donnell

• 2008 – Pennsylvania’s 18th congressional district (D) – lost

Tony O’Donnell

• 2012 – Maryland’s 5th congressional district (R) – lost

Tom M. O’Donoghue

• 2006 – Virginia’s 8th congressional district (R) – lost

Jerome X. O’Donovan

• 1988 – New York’s 14th congressional district (D, Independent Voter) – lost

Kieran O’Dougherty

• 1962 – United States Senate (New York) (C) – lost

Peter Paul O’Dwyer

• 1948 – New York’s 21st congressional district (D, American Labor) – lost
• 1968 – United States Senate (New York) (D) – lost

Florence T. O’Grady

• 1982 – New York’s 20th congressional district (RTL) – lost
• 1984 – New York’s 20th congressional district (RTL) – lost
• 1986 – New York’s 20th congressional district (RTL) – lost
• 1988 – New York’s 20th congressional district (RTL) – lost
• 1994 – New York’s 18th congressional district (RTL) – lost
• 1996 – New York’s 18th congressional district (RTL) – lost
• 2000 – New York’s 18th congressional district (RTL) – lost

Jack J. O’Grady

• 1948 – Indiana’s 6th congressional district (D) – lost

Marilyn F. O’Grady

• 2002 – New York’s 4th congressional district (R, CON, RTL) – lost
• 2004 – United States Senate (New York) (CON) – lost

Martin J. O’Grady

• 1988 – New York’s 19th congressional district (RTL) – lost
• 1992 – New York’s 17th congressional district (RTL) – lost

Walter O’Hagen

• 1936 – New York’s 36th congressional district (S) – lost
• 1938 – New York’s 36th congressional district (S) – lost
• 1944 – New York’s 38th congressional district (American Labor) – lost

Thomas Charles O’Halleran

• 2016 – Arizona’s 1st congressional district (D) – won
• 2018 – Arizona’s 1st congressional district (D) – won
• 2020 – Arizona’s 1st congressional district (D) – won
• 2022 – Arizona’s 2nd congressional district (D) – lost

Richard J. O’Halloran

• 1930 – Illinois’ 12th congressional district (D) – lost

Barratt O’Hara

• 1948 – Illinois’ 2nd congressional district (D) – won
• 1950 – Illinois’ 2nd congressional district (D) – lost
• 1952 – Illinois’ 2nd congressional district (D) – won
• 1954 – Illinois’ 2nd congressional district (D) – won
• 1956 – Illinois’ 2nd congressional district (D) – won
• 1958 – Illinois’ 2nd congressional district (D) – won
• 1960 – Illinois’ 2nd congressional district (D) – won
• 1962 – Illinois’ 2nd congressional district (D) – won
• 1964 – Illinois’ 2nd congressional district (D) – won
• 1966 – Illinois’ 2nd congressional district (D) – won

Frederic S. O’Hara

• 1956 – Illinois’ 21st congressional district (R) – lost

James F. O’Hara

• 1950 – New York’s 13th congressional district (R) – lost

James Grant O’Hara

• 1958 – Michigan’s 7th congressional district (D) – won
• 1960 – Michigan’s 7th congressional district (D) – won
• 1962 – Michigan’s 7th congressional district (D) – won
• 1964 – Michigan’s 12th congressional district (D) – won
• 1966 – Michigan’s 12th congressional district (D) – won
• 1968 – Michigan’s 12th congressional district (D) – won
• 1970 – Michigan’s 12th congressional district (D) – won
• 1972 – Michigan’s 12th congressional district (D) – won
• 1974 – Michigan’s 12th congressional district (D) – won

James J. O’Hara

• 1934 – Michigan’s 11th congressional district (R) – lost

James O’Hara

• 1920 – Nebraska’s 2nd congressional district (D) – lost

John Grady O’Hara

• 1958 – Tennessee’s 2nd congressional district (D) – lost

Joseph Patrick O’Hara

• 1938 – Minnesota’s 2nd congressional district (R) – lost
• 1940 – Minnesota’s 2nd congressional district (R) – won
• 1942 – Minnesota’s 2nd congressional district (R) – won
• 1944 – Minnesota’s 2nd congressional district (R) – won
• 1946 – Minnesota’s 2nd congressional district (R) – won
• 1948 – Minnesota’s 2nd congressional district (R) – won
• 1950 – Minnesota’s 2nd congressional district (R) – won
• 1952 – Minnesota’s 2nd congressional district (R) – won
• 1954 – Minnesota’s 2nd congressional district (R) – won
• 1956 – Minnesota’s 2nd congressional district (R) – won

Louis Dona G. O’Hara

• 1968 – Rhode Island’s 1st congressional district (I) – lost
• 1970 – Rhode Island’s 2nd congressional district (O’Hara Bill) – lost

Peter J. O’Hara

• 1990 – New York’s 1st congressional district (RTL) – lost

Shawn O’Hara

• 1992 – Mississippi’s 5th congressional district (I) – lost
• 2000 – United States Senate (Mississippi) (Ref.) – lost
• 2002 – United States Senate (Mississippi) (Ref.) – lost
• 2004 – Mississippi’s 2nd congressional district (Ref.) – lost
• 2012 – United States Senate (Mississippi) (Ref.) – lost
• 2014 – United States Senate (Mississippi) (Ref.) – lost
• 2016 – Mississippi’s 4th congressional district (Ref.) – lost
• 2018 – United States Senate (Mississippi) (Ref.) – lost

Thomas A. O’Hara

• 1924 – Pennsylvania’s 7th congressional district (D) – lost
• 1928 – Pennsylvania’s 7th congressional district (D) – lost

Bernard V. O’Hare

• 1928 – Pennsylvania’s 13th congressional district (D) – lost

Taylor Walters O’Hearn

• 1962 – United States Senate (Louisiana) (R) – lost

Dan O’Keefe

• 1978 – California’s 13th congressional district (R) – lost

Maurice P. O’Keefe

• 1928 – Kansas’ 1st congressional district (D) – lost

Raymond T. O’Keefe

• 1926 – United States Senate (Illinois) (Light Wines and Beer) – lost

Richard B. O’Keefe

• 1946 – Massachusetts’ 6th congressional district (D) – lost

Esther K. O’Keeffe

• 1922 – Indiana’s 13th congressional district (D) – lost

Joseph F. O’Kicki

• 1970 – Pennsylvania’s 22nd congressional district (D) – lost

Alvin Edward O’Konski

• 1942 – Wisconsin’s 10th congressional district (R) – won
• 1944 – Wisconsin’s 10th congressional district (R) – won
• 1946 – Wisconsin’s 10th congressional district (R) – won
• 1948 – Wisconsin’s 10th congressional district (R) – won
• 1950 – Wisconsin’s 10th congressional district (R) – won
• 1952 – Wisconsin’s 10th congressional district (R) – won
• 1954 – Wisconsin’s 10th congressional district (R) – won
• 1956 – Wisconsin’s 10th congressional district (R) – won
• 1958 – Wisconsin’s 10th congressional district (R) – won
• 1960 – Wisconsin’s 10th congressional district (R) – won
• 1962 – Wisconsin’s 10th congressional district (R) – won
• 1964 – Wisconsin’s 10th congressional district (R) – won
• 1966 – Wisconsin’s 10th congressional district (R) – won
• 1968 – Wisconsin’s 10th congressional district (R) – won
• 1970 – Wisconsin’s 10th congressional district (R) – won
• 1972 – Wisconsin’s 7th congressional district (R) – lost

Bernard J. O’Laughlin

• 1944 – United States Senate (North Dakota) (I) – lost

Arthur F. O’Leary

• 1926 – Connecticut’s 5th congressional district (D) – lost

J. A. O’Leary

• 1920 – New York’s 18th congressional district (FL) – lost

James Aloysius O’Leary

• 1934 – New York’s 11th congressional district (D) – won
• 1936 – New York’s 11th congressional district (D) – won
• 1938 – New York’s 11th congressional district (D) – won
• 1940 – New York’s 11th congressional district (D) – won
• 1942 – New York’s 11th congressional district (D, American Labor) – won

Richard A. O’Leary

• 1952 – New York’s 3rd congressional district (D) – lost

Thomas C. O’Leary

• 1938 – New York’s 22nd congressional district (American Labor) – lost