Marine Aviation and Training Support Group 33 (MATSG-33) is a United States Marine Corps aviation training group that was originally established during World War II as Marine Aircraft Group 33 (MAG-33). Fighter squadrons from MAG-33 fought most notably during the Battle of Okinawa and also as the first Marine aviation units to support the Korean War when they arrived as part of the 1st Provisional Marine Brigade. They helped stabilize the United Nations positions during the Battle of Pusan Perimeter and fought in Korea for the remainder of the war. At some point in the 1960s, the group was deactivated and was not reactivated until 2000, when Marine Aviation Training Support Group at Naval Air Station Oceana, Virginia was renamed MATSG-33.