Elections for Wisconsin's 8 seats in the United States House of Representatives were held on November 2, 2004. All of the incumbents won reelection except for Jerry Kleczka, who chose to retire.
Paul Ryan was first elected in 1998, and received 67% of the vote in 2002. Jeffrey Chapman Thomas was the Democratic nominee in 2000 and 2002.
Steve Gutschick initially sought the Democratic nomination, but withdrew citing poor fundraising. Chet Bell, the son of the mayor of West Allis, Wisconsin, announced his campaign for the Democratic nomination on June 4, 2004. In July 2004, Ryan had over $1 million in campaign funds compared to $4,212 held by Bell and $5.13 held by Thomas.