2012 United States Senate election in Missouri

The 2012 United States Senate election in Missouri was held on November 6, 2012, concurrently with the 2012 presidential election, elections to the United States Senate in other states, elections to the United States House of Representatives, and various state and local elections.

Incumbent senator Claire McCaskill was unopposed in the Democratic primary, and U.S. Representative Todd Akin won the Republican nomination with a plurality in a close three-way race. McCaskill's campaign purposely elevated Akin's chances in the primary, under the belief he would be the easiest candidate to defeat in the general election, due to his extreme views on social issues and strong religious views.

Years prior, many forecasters had considered McCaskill to be the most vulnerable Democratic senator seeking re-election in 2012, due to her low approval ratings and the state's rightward trend, with most analysts expecting a Republican pick-up. However, this election received considerable media coverage, due to controversial comments made by the eventual Republican nominee, Akin, most notably his claim that women could not get pregnant from rape. This led most analysts to reclassify the race as a "toss-up", and caused many major Republican Party figures to take back their endorsements, demand Akin withdraw from the election, and cut off fundraising.

Throughout most of the fall, the race continued to trend in McCaskill's favor and was reclassified as a likely Democratic hold.

McCaskill handily won a second term, with backlash against Akin from women, particularly suburban white women, being cited as the main reason. As of 2025, this was the last time the Democrats won a U.S. Senate election in Missouri.