Senators 17 / 21
Robert A. Hurley (1895)
Robert Burren Morgan (1925)
Robert G. Jones (1939)
Robert Morris (1734)
Robert N. Stanfield (1877)
Robert Rantoul Jr. (1805)
Robert Rice Reynolds (1884)
Robert Sheran (1916)
Robert Taft (1889)
Robert Taft Jr. (1917)
Robert Torricelli (1951)
Robert W. Upton (1884)
Robert Wilson (1803)
Robert Y. Hayne (1791)
Roel Degamo (1966)
Roger Sherman (1721)
Roger Wicker (1951)
Roland Burris (1937)
Roman Hruska (1904)
Ron Wyden (1949)
Roscoe Conkling (1829)
Rose McConnell Long (1892)
Roseller T. Lim (1915)
Ross Bass (1918)
Roxana Latorre (1952)
Royal S. Copeland (1868)
Rudy Boschwitz (1930)
Rufus C. Holman (1877)
Rufus Choate (1799)
Rufus King (1755)
Russ Feingold (1953)
S. I. Hayakawa (1906)
Sam Ervin (1896)
Sam G. Bratton (1888)
Sam Hanson (1939)
Sam Nunn (1938)
Samuel C. Crafts (1768)
Samuel C. Pomeroy (1816)
Samuel Cabanchik (1958)
Samuel G. Arnold (1821)