William H. Sylk
- 1942 – Pennsylvania’s 6th congressional district (R) – lost
Fred H. Sylvester
- 1920 – New York’s 43rd congressional district (D) – lost
Michael J. Sylvia III
- 2006 – New York’s 24th congressional district (L) – lost
James Wadsworth Symington
- 1968 – Missouri’s 2nd congressional district (D) – won
- 1970 – Missouri’s 2nd congressional district (D) – won
- 1972 – Missouri’s 2nd congressional district (D) – won
- 1974 – Missouri’s 2nd congressional district (D) – won
John Fife Symington, Jr.
- 1958 – Maryland’s 2nd congressional district (R) – lost
- 1960 – Maryland’s 2nd congressional district (R) – lost
- 1962 – Maryland’s 2nd congressional district (R) – lost
William Stuart Symington
- 1952 – United States Senate (Missouri) (D) – won
- 1958 – United States Senate (Missouri) (D) – won
- 1964 – United States Senate (Missouri) (D) – won
- 1970 – United States Senate (Missouri) (D) – won
Frank S. Symmonds
- 1934 – Wisconsin’s 1st congressional district (S) – lost
Steven Douglas Symms
- 1972 – Idaho’s 1st congressional district (R) – won
- 1974 – Idaho’s 1st congressional district (R) – won
- 1976 – Idaho’s 1st congressional district (R) – won
- 1978 – Idaho’s 1st congressional district (R) – won
- 1980 – United States Senate (Idaho) (R) – won
- 1986 – United States Senate (Idaho) (R) – won
T. W. Symons, Jr.
- 1930 – Washington’s 5th congressional district (R) – lost
Michael Lynn Synar
- 1978 – Oklahoma’s 2nd congressional district (D) – won
- 1980 – Oklahoma’s 2nd congressional district (D) – won
- 1982 – Oklahoma’s 2nd congressional district (D) – won
- 1984 – Oklahoma’s 2nd congressional district (D) – won
- 1986 – Oklahoma’s 2nd congressional district (D) – won
- 1988 – Oklahoma’s 2nd congressional district (D) – won
- 1990 – Oklahoma’s 2nd congressional district (D) – won
- 1992 – Oklahoma’s 2nd congressional district (D) – won
John T. Synnestvedt
- 1958 – Pennsylvania’s 13th congressional district (D) – lost
Frank W. Szabo
- 1994 – Pennsylvania’s 13th congressional district (Citizens with Szabo) – lost
John J. Szczepaniak
- 1936 – New York’s 42nd congressional district (I) – lost
Stanley Szelazek
- 1934 – New Jersey’s 13th congressional district (Comm.) – lost
Kathy Szeliga
- 2016 – United States Senate (Maryland) (R) – lost
Joseph Brian Szwaja
- 2000 – Washington’s 7th congressional district (G) – lost
William H. Szych
- 2006 – Massachusetts’ 1st congressional district (I) – lost
