Harker was an unincorporated community located in Collier County, Florida, United States, about 40 kilometres (25 mi) East of the city of Bonita Springs and 8 kilometres (5.0 mi) Southeast of the town of Immokalee. Most maps indicate that Harker is located on State Road 29 between West Main Street to the North and Oil Well Road to the South. West of Harker is , and to the East is the Okaloacoochee Slough. State Road 29 and the railroad were both built through Harker in the 1920s.