The battalion deployed to Kuwait in 2003 to become part of the invasion force that ousted Saddam Hussein. The Marines of 1/5 were the first to enter the country beginning combat operations the day prior to the war beginning. The battalion continued north in the coming weeks before ultimately participating in the battle for Baghdad. They returned again to Iraq as part of Operation Iraqi Freedom in early 2004 for security and stabilization operations in Al Anbar Province. In March 2004, the battalion, this time attached to the 1st Marine Regiment along with several other units, participated in Operation Vigilant Resolve in the restive city of Fallujah. They were deployed a third time in support of Operation Iraqi Freedom, one of only two Marine Corps infantry battalions to do so at the time, in the city of Ar Ramadi, capital of Al Anbar Province between March and October 2005.