1820 United States presidential election in Illinois

The 1820 United States presidential election in Illinois took place between 1 November and 6 December 1820, as part of the 1820 United States presidential election. Voters chose three representatives, or electors to the Electoral College, who voted for President and Vice President. It was the first Presidential election that Illinois participated in since being admitted to the Union on 3	December 1818.

Illinois cast three electoral votes for the Democratic-Republican candidate and incumbent President James Monroe, as he ran effectively unopposed. The electoral votes for Vice president were cast for Monroe's running mate Daniel D. Tompkins from New York. The state was divided into electoral districts with one elector each, whereupon each district's voters chose the electors.