The 9th Marine Expeditionary Brigade (9th MEB) was a United States Marine Corps unit activated in the early 1960s as part of the U.S. military buildup during the Vietnam War. Initially formed as a rapid-response force in Okinawa, the 9th MEB was deployed to Da Nang, South Vietnam, in March 1965, marking the first major commitment of U.S. combat troops to the conflict. The brigade played a key role in securing airbases and conducting operations against Viet Cong forces in the I Corps tactical zone. The 9th MEB was later expanded and redesignated as the 3rd Marine Division as the U.S. commitment in Vietnam grew.
