The 9th Marine Regiment was an infantry regiment of the United States Marine Corps. Formed during World War II, it served until 1994, when it was deactivated during the post Cold War drawdown. Battalions of the Ninth Marine Regiment, but not the regiment itself, were reactivated from 2007 to 2014 as part of the Marine Corps' growth during the wars in Iraq and Afghanistan. The battalions have subsequently been deactivated again.