Marine Corps Base Camp Pendleton is the major West Coast base of the United States Marine Corps and is one of the largest Marine Corps bases in the United States. It is on the Southern California coast in San Diego County and is bordered by Oceanside to the south, San Clemente and Orange County to the north, Riverside County to the northeast, and Fallbrook to the east.

The base was established in 1942 to train U.S. Marines for service in World War II. By October 1944, Camp Pendleton was declared a "permanent installation," and by 1946 it became the home of the 1st Marine Division. It was named after Major General Joseph Henry Pendleton (1860–1942), who had long advocated setting up a training base for the Marine Corps on the West Coast. Today it is home to myriad Operating Force units, including the I Marine Expeditionary Force and various training commands.