The 1928 United States Senate special election in Illinois took place on November 6, 1928.[1] The election was held due to the U.S. Senate's refusal to seat 1926 election winner, RepublicanFrank L. Smith, due to allegations of election fraud.[2][3][4] The election saw the election of Republican Otis F. Glenn.
The primaries and general election coincided with those for federal elections (president and House) and those for state elections.[1] Primaries were held April 10, 1928.[1]
Chicago mayor William Hale Thompson backed Smith for Senate, while Charles S. Deneen, who held Illinois' other U.S. Senate seat, backed Glenn. Thompson and Deneen controlled rival factions of the state's Republican Party.[6][7] Thompson's faction was vastly dominant at the time.[8]