Kentfield is a census-designated place (CDP) in Marin County, California, United States, just north of San Francisco. Kentfield is located 2 miles (3 km) southwest of downtown San Rafael, at an elevation of 115 feet. The population was 6,808 at the 2020 census. The ZIP codes are 94904 for street addresses, and 94914 for PO boxes, and are shared with the neighboring community of Greenbrae.

Marin County is located in the northwestern part of the San Francisco Bay Area of the U.S. state of California. As of the 2020 census, the population was 262,231. Its county seat and largest city is San Rafael. Marin County is across the Golden Gate Bridge from San Francisco, and is included in the San Francisco–Oakland–Berkeley, CA Metropolitan Statistical Area.