Mariposa (ˌmærɪˈpoʊzə,_-sə; Spanish for "Butterfly") is an unincorporated community and census-designated place (CDP) in and the county seat of Mariposa County, California, United States. The population was 1,526 at the 2020 census. The community is named after the flocks of monarch butterflies seen overwintering there by early explorers.
Mariposa is located at , at in elevation. It lies in the rugged foothills of the Sierra Nevada. Mariposa Creek flows through the town. Soils in the urban area are mostly brown to reddish brown loam of the Blasingame series. A gravelly loam is mapped as the Boomer series. These soils support thick grassland plus trees such as blue oak, black oak, gray pine, and ponderosa pine. To the west-northwest of town is a large area of sparse vegetation and rockland on which is found serpentine soil of the Henneke series.
California State Routes 49 and 140 cross in Mariposa, merging for as the town's main street. H