The 1934 United States Senate elections in Arizona took place on November 3, 1934. Incumbent Democratic U.S. Senator Henry F. Ashurst ran for reelection to a fifth term, defeating Republican nominee Joseph Edward Thompson in the general election by a wide margin.

1934 United States Senate election in Arizona

← 1928 November 3, 1934 1940 →

Nominee Henry F. Ashurst Joseph Edward Thompson Party Democratic Republican Popular vote 67,648 24,075 Percentage 72.03% 25.63%

County results Ashurst:      60–70%      70–80%      80–90%

United States Senator before election Henry F. Ashurst Democratic Elected United States Senator Henry F. Ashurst Democratic

Thompson's candidacy came at an inopportune time, as President Franklin D. Roosevelt had just begun his first term, and with the country in the midst of the Great Depression, the Democrats were far more popular than the Republicans at the time. Additionally, Ashurst, who had served continuously as U.S. Senator since Arizona joined the union in 1912, presented an even greater challenge to anyone who would have hoped to defeat him for reelection, due to his seniority, and Thompson was fairly unknown in state politics, having never served in government prior to running for U.S. Senate.

Ashurst notably faced opposition in the Democratic primary, however, from former Secretary of State Sidney P. Osborn, who later became Governor of Arizona for several terms. This would be Ashurst's final electoral success, as he would lose the Democratic primary in 1940 to Ernest McFarland.