Macclenny is a city and the county seat of Baker County, Florida. Located just west of Jacksonville, it is one of the principal municipalities comprising Greater Jacksonville. The population was 7,304 at the 2020 census, up from 6,374 in 2010.

Baker County is a county in the U.S. state of Florida. As of the 2020 census, the population was 28,259. Its county seat is Macclenny. The county was founded in 1861 and is named for James McNair Baker, a judge and Confederate Senator.