The 1990 United States Senate election in Minnesota was held on November 6, 1990. Incumbent Republican U.S. Senator Rudy Boschwitz was defeated by Democratic challenger Paul Wellstone in a tight race. Widely considered an underdog and outspent by a 7-to-1 margin, Wellstone was the only candidate to defeat an incumbent senator as well as the only candidate to flip a seat in the 1990 election cycle and gained national attention after his upset victory.