The House seat currently held by Democrat Stephanie Murphy will be in Republican hands when the 118th Congress convenes in January 2023.
Republican candidate Cory Mills, a US Army veteran turned defence contractor, defeated Democratic challenger Karen Green to flip the seat representing Florida’s Seventh Congressional District. It had been in Democratic hands since 2016 when Ms Murphy first won election to Congress.
The seat is the first of just five seats Republicans need to change hands in order to control the House of Representatives next year.
Ms Murphy, a moderate member of the bipartisan House Problem Solvers Caucus, is one of the seven Democrats who have been investigating the facts and circumstances of the worst attack on the Capitol since 1814 as part of the House January 6 select committee.
She announced her retirement from Congress after three terms this year rather than run in a redrawn district that heavily favoured the Republican candidate.
Republicans expect to pick up several of the five House seats they need thanks to Florida Governor Ron DeSantis, who personally intervened draw a map that was far more slanted towards the GOP than the Republican-controlled legislature had submitted for approval.