| I Field Force, Vietnam | |
|---|---|
I Field Force Vietnam shoulder sleeve insignia | |
| Active | 1966–1971 |
| Country | |
| Branch | |
| Type | Command |
| Size | Corps |
| Part of | |
| Headquarters | Nha Trang |
| Engagements | Vietnam War |
| Insignia | |
| Distinctive Unit Insignia | |
I Field Force, Vietnam was a corps-level command of the United States Army during the Vietnam War. Activated on 25 September 1965 as Field Force Vietnam, it was derived (with significant changes) from Task Force Alpha, a provisional corps command created 1 August 1965 for temporary control of activities of U.S. Army ground combat forces arriving in Vietnam. Field Force Vietnam was renamed I Field Force Vietnam on 15 March 1966. I Field Force was a component of U.S. Military Assistance Command Vietnam (MACV) and had its headquarters at Nha Trang.

I Field Force's area of responsibility was II Corps Tactical Zone, later renamed Military Region 2, which comprised the seven provinces of Vietnam's Central Highlands and five coastal provinces. (Task Force Alpha, the predecessor organization, had also controlled forces in III Corps Tactical Zone). Among the divisions and brigades under I Field Force Vietnam were:
I Field Force was inactivated on 30 April 1971 during the withdrawal of U.S. ground combat forces from Vietnam, and its assets formed the basis for its successor, the Second Regional Assistance Command (SRAC).