The 2000 United States Senate election in Delaware was held on November 7, 2000, in conjunction with the 2000 U.S. presidential election, other elections to the United States Senate in other states, as well as elections to the United States House of Representatives, and various state and local elections. Incumbent Republican U.S. Senator William Roth ran for re-election to a sixth term, but was defeated by Governor Tom Carper.