2018 United States Senate election in Missouri

The 2018 United States Senate election in Missouri took place on November 6, 2018, to elect a member of the United States Senate to represent the State of Missouri, concurrently with other elections to the United States Senate, elections to the United States House of Representatives, and various state and local elections, including Missouri's quadrennial State Auditor election.

This was one of ten Democratic-held Senate seats up for election in a state Donald Trump won in the 2016 presidential election. Incumbent Democratic Senator Claire McCaskill ran for re-election to a third term. McCaskill easily won her party's nomination, defeating several minor candidates in the primary, while Missouri Attorney General Josh Hawley comfortably won the Republican primary.

The candidate filing deadline was March 27, 2018, and the primary election was held on August 7, 2018. Pollsters predicted a tight race; however, Hawley defeated McCaskill on election day by 5.8%, taking 51.4% of the vote to McCaskill's 45.6%, a somewhat larger margin than expected. This resulted in Republicans holding both Senate seats in Missouri for the first time since McCaskill took office in 2007. Hawley was also the youngest incumbent senator at that time, and continued to be until the inauguration of Jon Ossoff in 2021. Despite her loss, McCaskill outperformed Hillary Clinton's performance in the state in the 2016 presidential race. This is the last U.S. Senate race in Missouri where the incumbent was defeated.

• Claire McCaskill, incumbent U.S. Senator

• Angelica Earl, former insurance verification specialist

• David Faust

• Travis Gonzalez, perennial candidate

• John Hogan, perennial candidate

• Leonard Steinman, perennial candidate

• Carla (Coffee) Wright

Results by county: .mw-parser-output .legend{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .legend-color{display:inline-block;min-width:1.25em;height:1.25em;line-height:1.25;margin:1px 0;text-align:center;border:1px solid black;background-color:transparent;color:black}.mw-parser-output .legend-text{}  McCaskill   80–90%   70–80%   60–70%   50–60%

• Josh Hawley, Missouri Attorney General

• Brian Hagg

• Bradley Krembs

• Tony Monetti, retired bomber pilot and assistant dean of aviation at University of Central Missouri

• Kristi Nichols, activist and candidate for the U.S. Senate in 2010 and 2016

• Ken Patterson, candidate for St. Louis County Executive in 2010

• Austin Petersen, businessman and Libertarian candidate for presidential nomination in 2016

• Peter Pfeifer

• Fred Ryman, Constitution nominee for the U.S. Senate in 2016

• Christina Smith

• Courtland Sykes, veteran and former congressional aide

• Camille Lombardi-Olive, Democratic candidate for MO-07 in 2016

• Paul Curtman, state representative

• Eric Greitens, former Governor of Missouri

• Marsha Haefner, state representative

• Vicky Hartzler, U.S. representative

• Aaron Hedlund, economics professor

• Ed Martin, former chairman of the Missouri Republican Party, nominee for MO-03 in 2010 and nominee for attorney general in 2012

• Todd Richardson, Speaker of the Missouri House of Representatives

• Eric Schmitt, state treasurer

• Ann Wagner, U.S. representative and former U.S. Ambassador to Luxembourg

• David Wasinger, attorney

Results by county:   Hawley   60–70%   50–60%   40–50%   Monetti   40–50%

• Japheth Campbell, entrepreneur

• Don Donald

• Dennis Lagares

• Alicia Dearn, attorney and candidate for vice president of the United States in 2016

• Austin Petersen, Libertarian candidate for president of the United States in 2016 (running as a Republican)

Results by county: Campbell   100% No votes   No votes

• Jo Crain

• Jerome Bauer

Results by county:   Crain   100%   80–90%   70–80%   60–70%   50–60%   Crain/Bauer tie   50%   Bauer   50–60%   60–70%   70–80%   80–90%   100% No votes   No votes

• Craig O'Dear, attorney

• Complete video of debate, October 18, 2018

State Senate districts results

State House districts results

Senator McCaskill conceded a few hours after the polls closed on election day. Despite performing strongly in the St. Louis suburbs, she ran well behind her 2012 vote in Southeast Missouri, especially in the Lead Belt and the Missouri Bootheel. She also ran poorly in the northern part of the state.

• Audrain (largest city: Mexico)
• Bates (largest city: Butler)
• Chariton (largest city: Salisbury)
• Clark (largest city: Kahoka)
• Clinton (largest city: Cameron)
• Daviess (largest city: Gallatin)
• Dunklin (largest city: Kennett)
• Franklin (largest city: Washington)
• Gentry (largest city: Albany)
• Grundy (largest city: Trenton)
• Henry (largest city: Clinton)
• Hickory (largest city: Hermitage)
• Howard (largest city: Fayette)
• Iron (largest city: Ironton)
• Knox (largest city: Edina)
• Lafayette (largest city: Odessa)
• Lewis (largest city: Canton)
• Linn (largest city: Brookfield)
• Livingston (largest city: Chillicothe)
• Madison (largest city: Fredericktown)
• Nodaway (largest city: Maryville)
• Pike (largest city: Bowling Green)
• Reynolds (largest city: Ellington)
• Schuyler (largest city: Lancaster)
• Scotland (largest city: Memphis)
• Scott (largest city: Sikeston)
• Shannon (largest city: Winona)
• St. Francois (largest city: Farmington)
• Sullivan (largest city: Milan)
• Wayne (largest city: Piedmont)
• Worth (largest city: Grant City)
• Buchanan (largest city: St. Joseph)
• Jefferson (largest city: Arnold)
• Mississippi (largest city: Charleston)
• New Madrid (largest city: New Madrid)
• Pemiscot (largest city: Caruthersville)
• Platte (largest city: Kansas City)
• Ray (largest city: Richmond)
• Saline (largest city: Marshall)
• Washington (largest city: Potosi)
• Sainte Genevieve (largest city: Ste. Genevieve)
• St. Charles (largest city: O'Fallon)
• Pettis (largest city: Sedalia)
• Pulaski (largest city: Fort Leonard Wood)
• Adair (largest city: Kirksville)
• Andrew (largest city: Savannah)
• Cass (largest city: Harrisonville)
• Greene (largest city: Springfield)
• Johnson (largest city: Warrensburg)

Hawley won five of eight congressional districts, with the remaining three going to McCaskill, including one that elected a Republican.

• Candidates at Vote Smart
• Candidates at Ballotpedia
• Campaign finance at FEC
• Campaign finance at OpenSecrets

Official campaign websites

• Japheth Campbell (L) for Senate
• Jo Crain (G) for Senate
• Josh Hawley (R) for Senate
• Claire McCaskill (D) for Senate Archived October 5, 2012, at the Wayback Machine
• Craig O'Dear (I) for Senate