Fallbrook is a census-designated place in northern San Diego County, California. Fallbrook had a population of 32,267 at the 2020 census. Fallbrook is immediately east of the U.S. Marine Corps’ Camp Pendleton. Fallbrook is known for its avocado groves and calls itself the “Avocado Capital of the World.

The Fallbrook Community Planning Area is approximately 44 square miles (110 km²). According to the United States Census Bureau, the CDP has a total area of 17.6 square miles (46 km²). 17.5 square miles (45 km²) of it is land and 0.03 square miles (0.078 km²) of it (0.19%) is water.