1964 United States presidential election in Mississippi

The 1964 United States presidential election in Mississippi was held on November 3, 1964, as part of the 1964 United States presidential election, which was held on that day throughout all fifty states and the District of Columbia. Voters chose seven electors, or representatives to the Electoral College, who voted for president and vice president.

Less than 10% of Mississippi's black population were registered voters. Governor Paul B. Johnson Jr. told Mississippians to disobey the Civil Rights Act of 1964.

Over ninety percent of Mississippi's electorate viewed President Johnson as having done a bad job and 96.4 percent opposed the Civil Rights Act, compared to only 54 percent in the antebellum slave states and Oklahoma. 87 percent of Mississippi voters, vis-à-vis 48 percent in the South as a whole, believed that President Johnson was failing at countering domestic Communism. This reflected the widespread belief among Mississippi whites that civil rights activists were funded by communists.

Campaign
Neither Governor Johnson nor any other major state or federal politician offered President Johnson any support in his statewide campaign, which was left to inexperienced Greenville lawyer Douglas Wynn. Governor Johnson and four of the state's five Congressmen were silent about supporting Goldwater, though Congressman John Bell Williams supported him openly.

In July, polling suggested Goldwater would receive ninety percent of Mississippi's vote, but this fell to seventy in August and to between sixty and sixty-five in October due to fears that he would abolish the Rural Electrification Administration. By the weekend before election day, University of California political scientist Peter H. Odegard believed that Goldwater would win only Alabama and Mississippi.

Ultimately, Goldwater won Mississippi with a 74.28 point margin of victory over Johnson, making Mississippi 97% more Republican than the nation and Goldwater the first Republican to win the state since Reconstruction. While Goldwater would suffer a landslide defeat to Johnson in both the national popular vote and Electoral College, his performance in Mississippi was the largest statewide percentage victory by any Republican presidential nominee. Goldwater defeated Johnson by a margin comparable to what had been predicted in the earliest polls, and much greater than predicted immediately before the election. Over-representation of urban areas in polling was blamed for this discrepancy. As of the 2020 presidential election, this is the last time that Claiborne, Holmes and Jefferson counties voted for a Republican presidential candidate. Goldwater received 90% of the white vote in the state.