Marathon is located in Monroe County, FL. The population is 8,389, making Marathon the 3rd largest city in Monroe County.
There are 2 public schools in Marathon with an average Homefacts rating of B-. The total crime rate for Marathon is very low , and there are 18 registered sex offenders residing in the city. Unemployment in Marathon is low and the median home sales price is $0. Detailed and up-to-date Marathon property reports are available for any property address.
Cities near Marathon include Key Colony Beach, Duck Key and Layton.