The 1912 United States Senate elections in Arizona took place in the Arizona State Legislature on March 27, 1912, confirming the selection of Marcus A. Smith and Henry F. Ashurst as the state's first U.S. Senators. Their results were pre-determined on the basis on the results of a popular vote taken on December 12, 1911.

Henry Fountain Ashurst was an American Democratic politician and one of the first two senators from Arizona. Largely self-educated, he served as a district attorney and member of the Arizona Territorial legislature before fulfilling his childhood ambition of joining the United States Senate. During his time in the Senate, Ashurst was chairman of the Committee on Indian Affairs and the Judiciary Committee.