Five years later, the battalion was reactivated on 20 June 1951 at Camp Pendleton, California and was assigned to the 3rd Marine Division.

They participated in the Vietnam War from April 1965 to September 1969, operating from Phu Bai, Danang, Cam Lộ, Khe Sanh and Camp Carroll.

The battalion deployed in June 1971 to Kaneohe Bay, Hawaii and was later reassigned to the 1st Marine Brigade.

From July 2004 through April 2005, Charlie Battery, 1st Battalion, 12th Marines, deployed in support of Operation Iraqi Freedom.

They were attached to 1st Battalion, 3rd Marines and deployed to Fallujah, Iraq participating in Operation Phantom Fury.

From March 2007 through October 2007 and September 2008 through April 2009, 1st Battalion 12th Marines conducted the provisional mission of Task Force MP operating in the Al Anbar province of Iraq.

In April 2011, Charlie, Alpha and Headquarters and Service Battery of 1/12 deployed to Helmand Province, with Echo Battery of 2/12 deployed to Outpost Shrine in Kajaki, Afghanistan to replace 1st Battalion, 10th Marines as the main artillery unit in the area.