Jerry Demings, the mayor of Orange County, Fla., has filed to run for governor next year as a Democrat, expanding the field of candidates seeking to replace Gov. Ron DeSantis, a term-limited Republican.

Mr. Demings has led the county, home to Orlando and one of the few places in the state that still lean left, since 2018. Three years ago, his wife, former Representative Val Demings, ran unsuccessfully against Senator Marco Rubio, who later became President Trump’s secretary of state. Mr. Demings is a former Orange County sheriff and a former police chief in Orlando, Florida’s fourth-largest city.

Mr. Demings could prove a strong primary challenger for David Jolly, a former Republican congressman who has been campaigning for governor as a Democrat since June.

“In terms of my political philosophy, I’m more of a centrist,” Mr. Demings told The New York Times in an interview last month, as chatter about his potential candidacy grew. The county mayor position is nonpartisan, he noted, though he won three elections for sheriff as a Democrat.

The leading Republican candidate so far in the 2026 governor’s race is Representative Byron Donalds of Naples, whom Mr. Trump has endorsed. Paul Renner, a former speaker of the Florida House, is also running. Mr. DeSantis has not yet backed any Republican in the race; both his wife, Casey DeSantis, and his lieutenant governor, Jay Collins, have been considering runs.