The 1968 United States Senate election in Arizona took place on November 5, 1968. Incumbent Democratic U.S. Senator Carl Hayden did not run for reelection to an eighth term, with his longtime staff member Roy Elson running as the Democratic Party nominee to replace him. Elson was defeated by a wide margin, however, by former U.S. Senator and 1964 Republican presidential nominee Barry Goldwater. Prior to Goldwater's election, the seat had been held for decades by the Democratic Party under Carl Hayden, and has thus far remained in Republican Party control since.