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. Major attractions include Saint Marys Church and Baker Free Public Library .Among the biggest companies in MacClenny are Wells Fargo & Company and South Financial Group Inc. The biggest schools here are Baker County Middle School and university of Florida. One of the best places to visit when you are in MacClenny is Baker Free Public Library. Famous persons from MacClenny include Gary Dopson.