Two Rock is an unincorporated community in Sonoma County, California, United States. It is located on Stemple Creek in a rural area west of Petaluma. A hill named Dos Piedras overlooks the community from the north. The community is named for the two rocks, between which the Mexican trail from San Rafael to Bodega passed. Two Rock had a post office located at the intersection of Bloomfield and Tomales Road, as well as a school 1.3 miles west of the former post office, on Tomales Road.