About Marion County Marion County is the 5th largest county in the State of Florida encompassing 1,652 square miles or 1.03 million acres. It is ranked as the 19th fastest growing area in the nation with a current population of 258,916.
Employment is primarily industrial, medical, and service related.
It is centrally located with easy access to I-75, US 27, US 441, SR 40, and SR 200.