Bonsall is a census-designated place (CDP) in San Diego County, California. The population was 3,982 at the 2010 census, up from 3,401 at the 2000 census.
Bonsall is located just east of Oceanside and Camp Pendleton.
According to the United States Census Bureau, the CDP has a total area of 13.6 square miles (35.1 km²). 13.4 square miles (34.7 km²) of it is land and 0.2 square miles (0.4 km²) of it (1.28%) is water.