The 1964 United States Senate election in Arizona took place on November 3, 1964. Incumbent Republican U.S. Senator Barry Goldwater decided not to run for reelection to a third term, instead running for President of the United States as the Republican Party nominee against Lyndon B. Johnson. Governor of Arizona Paul Fannin ran unopposed in the Republican primary, and defeated Democratic nominee Roy Elson, who was a staff member for U.S. Senator Carl Hayden until Hayden's retirement in 1969.
Despite a landslide loss throughout the country, and Goldwater only able to obtain 50.45% of the vote in his home state of Arizona, Fannin managed to prevail in the state's Senate election.