The 2008 United States Senate election in Iowa was held on November 4, 2008. Incumbent Democratic U.S. Senator Tom Harkin sought re-election to a fifth term in office. Unlike Harkin's three previous reelection bids, he was not challenged by a sitting United States Congressman but instead faced small businessman Christopher Reed, who won the Republican primary by just a few hundred votes. Harkin defeated Reed in a landslide, winning 94 of Iowa's 99 counties. As of 2021, this is the most recent election in which a Democrat won a U.S. Senate election in Iowa.