Macclenny is a city in Baker County, Florida, United States. The population was 4,459 at the 2000 census. It is the county seat of Baker County. As of 2010, the population recorded by the U.S. Census Bureau is 6,374.
Macclenny is located at 30°17′N 82°7′W / 30.283°N 82.117°W / 30.283; -82.117.
According to the United States Census Bureau, the city has a total area of 3.3 square miles (8.5 km²), all of it land.