Operation Double Eagle was a US Marine Corps and Army of the Republic of Vietnam (ARVN) operation that took place in southern Quảng Ngãi Province, lasting from 28 January to 17 February 1966, during the Vietnam War. The operation was mounted in conjunction with Operation Masher in northern Bình Định Province. The operation was inconclusive as the People's Army of Vietnam (PAVN) and the Vietcong (VC) had largely slipped away.

Operation Masher, also known as Operation White Wing, was the largest search and destroy mission that had been carried out in the Vietnam War up until that time. It was a combined mission of the United States Army, Army of the Republic of Vietnam (ARVN), and Republic of Korea Army (ROK) in Bình Định Province on the central coast of South Vietnam. The People's Army of Vietnam (PAVN) 3rd Division, made up of two regiments of North Vietnamese regulars and one regiment of main force Viet Cong (VC) guerrillas, controlled much of the land and many of the people of Bình Định Province, which had a total population of about 800,000. A CIA report in 1965 said that Binh Dinh was "just about lost" to the communists.