The 1st Marine Division is a Marine division of the United States Marine Corps headquartered at Marine Corps Base Camp Pendleton, California. It is the ground combat element of the I Marine Expeditionary Force.

The 1st Marine Regiment is an infantry regiment of the United States Marine Corps based at Marine Corps Base Camp Pendleton, California. The regiment is under the command of the 1st Marine Division and the I Marine Expeditionary Force. The 1st Marine Regiment is also sometimes referred to as "Regimental Combat Team 1" or "Inchon".