Bonsall is a census-designated place (CDP) in San Diego County, California. The population was 4,546 at the 2020 census, up from 3,982 at the 2010 census.

The Bonsall area was heavily affected by the Lilac Fire in December 2017, which burned 4,100 acres.

Name

The area known as Bonsall was originally called Mount Fairview and had a post office by that name from December 28, 1871, to December 28, 1880. It received a post office in 1881 under the name Osgood, after California Southern Railroad chief engineer Joseph O. Osgood; the renaming was supposedly an unsuccessful attempt to convince Osgood to build the railroad through the San Luis Rey River Valley (the rail line eventually followed the Santa Margarita River instead). Following a contest, the town was renamed Bonsall in 1890, after local minister James A. Bonsall.

Geography

Bonsall is just east of Oceanside and Camp Pendleton, north of Vista and northwest of Hidden Meadows.

According to the United States Census Bureau, the CDP has a total area of . The is land whereas or (1.28%) is water.

Demographics