This is a list of notable performances of third party and independent candidates in elections to the United States Senate.

It is rare for candidates, other than those of the six parties which have succeeded as major parties (Federalist Party, Democratic-Republican Party, National Republican Party, Democratic Party, Whig Party, Republican Party), to take large shares of the vote in elections.

In some of the listed cases a faction or factions of a state's major party ran against each other, often making it difficult to ascertain which was the mainline candidate and which was the bolter; in such cases, those candidates which are not listed on a standard major party line are still listed, but are not considered traditional third party victories as often these candidates sat in Congress as affiliated party members (barring cases like Joe Lieberman who, upon winning re-election in 2006 as a third-party candidate, sat as an Independent Democrat).

Listed below are Senate elections in which a third party or independent candidate won at least 5.0% of the vote. Winners are shown in bold and marked "elected" or "re-elected".

Indirect elections (before 1918) Prior to the passage of the 17th Amendment, most states did not hold direct elections to the Senate, with senators instead being elected by the state legislatures. The results listed below are cases in which a third-party candidate won at least 5.0% of the legislative vote.

+ Notable third-party senatorial performances (1820s–1917)YearStatePartyNominee# Votes% VotesPlaceNotes1829New York (special)Anti-MasonicAmbrose Spencer223rd1830PennsylvaniaAnti-MasonicHarmar Denny104th1831New YorkAnti-MasonicSamuel Works322ndPennsylvania – Class I (special)Anti-MasonicRichard Rush303rd1832PennsylvaniaAnti-MasonicWilliam Clark282nd1833New York (special)Anti-MasonicJohn C. Spencer112nd1834Pennsylvania – Class III (special)Anti-MasonicAmos Ellmaker312nd1845New York – Class I (special)Native AmericanJonathan Thompson173rdNew York – Class III (special)Native AmericanHarmon B. Cropsey173rdNew YorkNative AmericanRobert Taylor153rd1849New YorkFree SoilJohn Adams Dix212nd1851MassachusettsFree SoilCharles Sumner?Elected1855Massachusetts (special)AmericanHenry Wilson255ElectedAmericanNahum F. Bryant852nd1857New YorkAmericanJoel T. Headley153rd1879PennsylvaniaGreenback PartyDaniel Agnew163rd1894NebraskaIndependentTechnically designation is UnknownW. A. Jones182nd1898NebraskaPeople'sWilliam V. Allen582nd1901NebraskaPeople'sWilliam V. Allen582nd

Direct elections (after 1905)

1900–1930 + Notable third-party senatorial performances (1900s–1930)YearStatePartyNominee# Votes% VotesPlace1905Oregon (special)SocialistJ. D. Stevens12,4852ndProhibitionHiram Gould8,2243rd1906OregonSocialistA. G. Simola5,6083rd1910NevadaSocialistJud Harris1,9593rd1912Arizona (special) – Class ISocialistE. Johnson1,2343rdArizona (special) – Class IIISocialistE. B. Simonton1,2213rdColoradoProgressiveFrank D. Catlin58,6493rdKansasSocialistAllan W. Ricker25,6103rdMontanaProgressiveJoseph M. Dixon22,1612ndNevada (special)SocialistG. A. Steele2,7403rdProgressiveSardis Summerfield1,4284thOklahomaSocialistJohn G. Wills40,8603rdOregonIndependentListed on ballot as "Popular Government Candidate"Jonathan Bourne Jr.25,9293rdSocialistBenjamin Franklin Ramp11,0934thProgressiveA. E. Clark11,0835thProhibitionB. Lee Paget6,8486th1914ArizonaProhibitionEugene W. Chafin7,2933rdSocialistBert Davis3,5824thProgressiveJ. Bernard Nelson2,6085thCaliforniaProgressiveFrancis J. Heney255,2322ndSocialistErnest Untermann3,5824thColoradoProgressiveBenjamin Griffith27,0723rdSocialistJ. C. Griffiths13,9434thIdahoProgressivePaul Clagstone10,3213rdSocialistCalistus W. Cooper7,8884thIllinoisProgressiveRaymond Robins203,0273rdIndianaProgressiveAlbert J. Beveridge108,5813rdIowaIndependentOtis Spurgeon24,4903rdKansasProgressiveVictor Murdock116,7553rdNevadaSocialistAshley Grant Miller5,4513rdNorth DakotaSocialistW. H. Brown6,2313rdOhioProgressiveArthur Lovett Garford67,5093rdOklahomaSocialistPatrick S. Nagle52,2593rdOregonProgressiveWilliam Hanley26,2203rdPennsylvaniaProgressiveGifford Pinchot269,2652ndWashingtonProgressiveOle Hanson83,2823rdSocialistAdam H. Barth30,2344th1916ArizonaSocialistW. S. Bradford2,8273rdCaliforniaSocialistWalter Thomas Mills49,3413rdMinnesotaProhibitionWillis Greenleaf Calderwood78,4253rdMontanaSocialistHenry La Beau9,2923rdNevadaSocialistAshley Grant Miller9,5073rdNorth DakotaSocialistE. R. Fry8,4723rdWashingtonSocialistBruce Rogers21,7093rdWisconsinSocialistRichard Elsner28,9083rd1918MassachusettsIndependentThomas W. Lawson21,9853rdMinnesotaNationalistWillis Greenleaf Calderwood137,3342ndMontanaNationalistJeannette Rankin26,0133rdNevada (special)IndependentAnne Henrietta Martin4,6033rdOregon (special)SocialistMartha Bean19,0142ndSouth DakotaIndependentOrville V. Rafferty5,5603rd1920CaliforniaProhibitionJames S. Edwards57,7683rdGeorgiaIndependentListed on ballot as "Pro-League Independent Party"Harry S. Edwards6,7002ndMarylandIndependentGeorge D. Iverson Jr.21,3453rdNevadaIndependentAnne Henrietta Martin4,9813rdNew YorkSocialistJacob Panken208,1553rdProhibitionElla A. Boole159,6234thPennsylvaniaProhibitionLeah C. Marion132,6103rdSouth DakotaNonpartisan LeagueTom Ayres44,3092ndIndependentRichard Olsen Richards10,0324thWashingtonFarmer–LaborC. L. France99,3092ndWisconsinProgressive RepublicanListed on ballot as "La Follette Progressive Republican National Platform"James Thompson235,0292ndSocialistFrank J. Weber66,1724th1922CaliforniaIndependentH. Clay Needham70,7483rdSocialistUpton Sinclair56,9824thFloridaIndependent RepublicanW. C. Lawson6,0742ndMinnesotaFarmer–LaborHenrik Shipstead325,372ElectedPennsylvania (special)ProhibitionRachel C. Robinson60,3902ndSocialistWilliam J. Van Essen55,7033rdPennsylvaniaProgressiveWilliam J. Burke127,1803rdWashingtonFarmer–LaborJames A. Duncan35,3263rd1923Minnesota (special)Farmer–LaborMagnus Johnson290,1651924ColoradoFarmer–LaborMorton Alexander16,0393rdColorado (special)Farmer–LaborCharles T. Phelps17,5423rdMinnesotaFarmer–LaborMagnus Johnson380,6462ndOregonProgressiveF. E. Coulter20,3793rdSouth DakotaFarmer–LaborTom Ayres23,9623rdIndependentGeorge W. Egan14,3904th1926IdahoProgressiveH. F. Samuels37,0472ndIllinoisIndependent RepublicanHugh S. Magill156,2453rdNew YorkIndependent RepublicanFranklin W. Cristman231,9063rdNorth Dakota (special)Nonpartisan LeagueGerald Nye79,709Re-electedIndependent RepublicanC. P. Stone19,5863rdNorth DakotaIndependent RepublicanListed on ballot as "Agricultural Relief Republican"Norris H. Nelson18,9512ndIndependent RepublicanListed on ballot as "Republican for Beer and Wine"C. P. Stone9,7384thOregonIndependentRobert N. Stanfield50,2463rdSouth DakotaFarmer–LaborHoward Platt12,7973rdWisconsinIndependent Progressive RepublicanCharles D. Rosa111,1222ndSocialistLeo Krzycki31,3174th1928CaliforniaProhibitionCharles Hiram Randall92,1063rdMinnesotaFarmer–LaborHenrik Shipstead665,169Re-electedWisconsinIndependent RepublicanWilliam H. Markham81,3022nd1930AlabamaIndependentJames Thomas Heflin100,9522ndMinnesotaFarmer–LaborErnest Lundeen178,6713rdOregonIndependentLlewellyn A. Banks17,4883rdVirginiaIndependentJ. Cloyd Byars26,0912ndSocialistJoe C. Morgan7,9443rd

1931–1960 + Notable third-party senatorial performances (1931–1960)YearStatePartyNominee# Votes% VotesPlaceNotes1932Arkansas (special)IndependentRex Floyd1,7522ndCaliforniaProhibitionRobert P. Shuler560,0883rdKansasIndependentGeorge A. Brown65,5833rdWisconsinSocialistEmil Seidel65,8073rd1934CaliforniaSocialistGeorge Ross Kirkpatrick108,7482ndMinnesotaFarmer–LaborHenrik Shipstead503,379Re-electedNew YorkSocialistNorman Thomas194,9523rdTennessee (special)IndependentListed on ballot as "Good Government and Clean Elections"John Randolph Neal Jr.49,7732ndWisconsinProgressiveRobert M. La Follette Jr.440,513Re-elected1936DelawareIndependent RepublicanRobert G. Houston6,8973rdMassachusettsUnionThomas C. O'Brien134,2453rdMinnesota (special)IndependentNathaniel John Holmburg210,3642ndIndependent ProgressiveAndrew Olaf Devold147,8583rdMinnesotaFarmer–LaborErnest Lundeen663,363ElectedMontanaIndependentJoseph P. Monaghan39,6553rdNebraskaIndependentGeorge W. Norris258,700Re-electedRhode IslandUnionLudger LaPointe21,4953rd1937Arkansas (special)IndependentJohn E. Miller65,802Elected1938ConnecticutSocialistBellani Trombley99,2823rdNorth DakotaIndependentListed as "Nonpartisan, Progressive, Old Age Pension"William Langer112,0072ndWisconsinProgressiveHerman Ekern249,2092nd1940CaliforniaProhibitionFred Dyster366,0442ndMinnesotaFarmer–LaborElmer Austin Benson310,8752ndNorth DakotaProgressive RepublicanListed as "Progressive Republican for Clean Government"William Lemke92,5932ndWisconsinProgressiveRobert M. La Follette Jr.605,609Re-elected1942Minnesota (special)Farmer–LaborAl Hansen177,0082ndMinnesotaFarmer–LaborElmer Austin Benson213,9652ndIndependent ProgressiveMartin A. Nelson109,2263rdNebraskaIndependentGeorge W. Norris108,8992ndVirginiaSocialistLawrence S. Wilkes5,6902nd1944North DakotaIndependentLynn U. Stambaugh44,5963rdWisconsinProgressiveHarry Sauthoff73,0893rd1946North DakotaIndependentArthur E. Thompson38,8042ndNorth Dakota (special)IndependentGerald Nye20,8483rdTennesseeIndependentJohn Randolph Neal Jr.11,5163rd1948ArkansasIndependentArthur E. Thompson15,8212nd1950AlabamaIndependentJohn G. Crommelin38,4772ndNew HampshireIndependent (write-in)Wesley Powell11,9582nd1952CaliforniaProgressiveReuben W. Borough542,2702ndMaineIndependent DemocratEarl S. Grant15,2943rdNew YorkLiberalGeorge Counts489,7753rdNorth DakotaIndependent (write-in)Fred G. Aandahl24,7413rdVirginiaIndependent DemocratH.M. Vise Sr.69,1332ndSocial DemocraticClarke T. Robb67,2813rd1954South CarolinaIndependent Democrat (write-in)Strom Thurmond143,444ElectedVirginiaIndependent DemocratCharles W. Lewis Jr.32,6812ndSocial DemocraticClarke T. Robb28,9223rd1958UtahIndependentJ. Bracken Lee77,0133rdVirginiaIndependentLouise Wensel120,2242nd1960VirginiaIndependent DemocratStuart D. Baker88,7182nd

1961–1990 + Notable third-party senatorial performances (1961–1990)YearStatePartyNominee# Votes% VotesPlaceNotes1964VirginiaIndependentJames W. Respess95,5263rd1966MississippiIndependentClifton R. Whitley30,5023rdVirginia (special)IndependentJohn W. Carter57,6923rdVirginiaIndependentF. Lee Hawthorne58,2513rd1968AlabamaNational DemocraticRobert Schwenn72,6993rdAlaskaDemocratic (write-in)Ernest Gruening14,1183rdMarylandAmerican IndependentGeorge P. Mahoney148,4673rdNew YorkConservativeJames L. Buckley1,139,4023rd1970ConnecticutIndependentThomas J. Dodd266,4973rdMississippiIndependentWilliam R. Thompson37,5932ndNew YorkConservativeJames L. Buckley2,288,190ElectedVirginiaIndependentHarry F. Byrd Jr.506,237Re-elected1972LouisianaIndependentJohn McKeithen250,1612nd1974FloridaAmerican IndependentJohn Grady282,6593rdHawaiiPeople'sJames D. Kimmel42,7672ndNew YorkConservativeBarbara A. Keating822,5843rdUtahAmericanBruce Bangerter24,9663rd1976MinnesotaAmerican IndependentPaul Helm125,6123rdVirginiaIndependentHarry F. Byrd Jr.890,778Re-elected1978AlabamaProhibitionJerome B. Couch34,9512ndArkansasIndependentJohn J. Black37,4883rdMaineIndependentHayes E. Gahagan27,8243rdMississippiIndependentCharles Evers133,6463rd1980New YorkLiberalJacob Javits664,5443rd1982WashingtonIndependentKing Lysen72,2973rd1984TennesseeIndependentEd McAteer87,2343rd1990VirginiaIndependentNancy B. Spannaus196,7552nd

1991–2020