Groveland-Big Oak Flat is an unincorporated community and former census-designated place (CDP) in Tuolumne County, California, United States. The population was 3,388 at the 2000 census. This CDP included the communities of Groveland, Big Oak Flat and Pine Mountain Lake (PML).
The CDP was abolished prior to the 2010 census, and Groveland and Pine Mountain Lake were made into separate CDPs.
The town hosts an annual 49er Festival on the 3rd Saturday of September, hosted by the Yosemite Chamber of Commerce, . Groveland is the location of the Groveland Ranger District office of the Stanislaus National Forest. The Groveland Community Services District provides services, including fire protection, to the community . The Department of Forestry and Fire Protection, Tuolumne-Calaveras Ranger Unit, Battalion 16, has a Forest Fire Station west of Groveland on State Route 120.
Groveland-Big Oak Flat is located at 37°50′45″N 120°12′28″W. Elevation is 867 m (2,846 ft).
According to the United States Census Bureau, the CDP has a total area of 28.8 square miles (75 km2), of which, 28.5 square miles (74 km2) of it is land and 0.3 square miles (0.78 km2) of it (0.90%) is water.