1920 United States Senate election in Arizona

The 1920 United States Senate election in Arizona took place on November 2, 1920. Incumbent Democratic U.S. Senator Marcus A. Smith ran for reelection to a third term, but was defeated by former Delegate to the U.S. House of Representatives from the Arizona Territory Ralph H. Cameron in the general election. Cameron would become the first Republican elected to the office of U.S. Senator from Arizona since the state joined the union in 1912. The same year, Republican Governor Thomas Edward Campbell was reelected to a second term.

Democratic primary
The Democratic primary took place on September 8, 1920. Incumbent U.S. Senator Marcus A. Smith was the recipient of a significant challenge in the Democratic primary, notably by Maricopa County Superior Court judge Rawghlie Clement Stanford, who would go on to become Arizona's fifth Governor in 1937. Fellow lawyer Albinus A. Worsley, as well as John W. Norton also ran in the primary. Smith narrowly staved off his primary challengers and went on to compete in the general election in November.

Candidates

 * Marcus A. Smith, incumbent U.S. Senator
 * Rawghlie Clement Stanford, Maricopa County Superior Court
 * Albinus A. Worsley, lawyer
 * John W. Norton

Candidates

 * Ralph H. Cameron, Delegate to the U.S. House of Representatives from the Arizona Territory
 * Elias S. Clark, Arizona Territorial Attorney General
 * Thomas Maddock, Arizona State Highway Engineer
 * Edward Robinson