Coreopsis stillmanii is a species of flowering plant in the daisy family known by the common name Stillman's tickseed. It is endemic to California, where it grows in the Central Valley and most of the adjacent coastal and inland mountain ranges in California chaparral and woodlands habitats. It is found east of San Francisco Bay (Contra Costa, Alameda, Santa Clara, Stanislaus Counties) and on the eastern side of the Central Valley (from Placer County to Fresno County).