Face coverings will be required inside all Hillsborough County facilities beginning Monday, August 2.
The new safety guidelines come as COVID-19 cases continue to surge in Florida.
According to the county, face coverings will be required not only for county employees but also visitors, despite their vaccination status.
"The measure is being taken as a precaution for the health and safety of County employees as well as residents," the county said in a press release.
County facilities, which the guidelines apply to, include libraries, parks and the Frederick B. Karl County Center.
The safety guidelines will also affect in-person public comments at the Board of County Commissioners (BOCC) meetings, beginning Aug. 4.