|1st Marine Division|
|Founded||1st February 1941|
|Country||United States of America|
|Branch||United States Marine Corps|
|Type||Ground combat element|
|Size||Marine Division (approximately 22,000)|
|Part of||I Marine Expeditionary Force|
|Garrison/HQ||Marine Corps Base Camp Pendleton|
|Nickname(s)||The Old Breed|
|Motto(s)||No Better Friend, No Worse Enemy|
|Commander||MajGen Benjamin T. Watson|
The 1st Marine Division (1st MARDIV) 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 (I MEF).
It is the oldest and largest active duty division in the United States Marine Corps, representing a combat-ready force of 22,000 personnel. It is one of three active duty divisions in the Marine Corps today and is a multi-role, expeditionary ground combat force. It is nicknamed "The Old Breed".