1900 United States presidential election in Missouri

The 1900 United States presidential election in Missouri took place on November 6, 1900. Voters chose 17 electors to represent them in the Electoral College via a popular vote, pitting incumbent Republican President William McKinley and his running mate Theodore Roosevelt against the Democratic ticket of challenger William Jennings Bryan and Adlai Stevenson.

Missouri gave Bryan a 51.48 percent of the vote versus McKinley's 45.94 percent, a margin of 5.53%. While losing Missouri, McKinley nevertheless won the national election by a 6.13 point margin.

Notably, this was one of only two occasions in the 20th century that Missouri voted for a losing presidential candidate, as the state was often considered a political bellwether in that period. Between 1904 and 2004, the state voted for the national winner in every election except for 1956 (coincidentally, Missouri voted for Stevenson's grandson in that election). However, that reputation began to fade after voting for losing Republican candidates for two elections in a row in 2008 and 2012. McKinley was the only president in American history to win two terms in office and lose Missouri twice until 2012, and is the only Republican president to ever do so.

Bryan had previously defeated McKinley in Missouri four years earlier but would later lose the state to William Howard Taft in 1908.