The 2004 United States Senate election in Florida took place on November 2, 2004 alongside 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
Democratic U.S. Senator
Bob Graham decided to retire instead of seeking a fourth term. Graham made an unsuccessful bid for the Democratic presidential nomination. The primary elections were held on August 31, 2004. Republican
Mel Martínez won the open seat with 49.4% of the vote to Democratic nominee
Betty Castor's 48.3%. With a margin of 1.1%, this election was the closest race of the
2004 Senate election cycle. This was the first open-seat United States Senate election in Florida for this seat since
1974.