The 2006 United States Senate election in Wyoming was held on November 7, 2006. The primaries were on August 22, 2006, in which both candidates were unopposed. Incumbent Republican U.S. Senator Craig Thomas won re-election to a third term. Thomas died 5 months into his term on June 4, 2007 after battling leukemia.
Thomas was a very popular two term incumbent, having a 68% approval rating. Despite doing very well in the polls, Thomas agreed to a debate. An October debate was sponsored by the Casper Star-Tribune and KCWY in Casper. Thomas said the nation has made progress in its energy policy, while Groutage said the nation's energy policy has failed because Congress has done more for special interests than the people.