Keysville is an unincorporated community in southeastern Hillsborough County, Florida, United States, adjacent to Lithia.

In 1880, Keysville reached a population of over 500, making it the second largest community in the county, after Tampa.

In the late nineteenth century it was served by passenger trains, but after the depletion of the timber resources, it declined.

In the early 1900s the town experienced a small revival with the opening of numerous phosphate mines in the area.

[4] The community of Keysville is served by Hillsborough County Schools.