In October 1964, Princeton exchanged WestPac training for the real thing as she returned to Vietnam and joined the Pacific Fleet's Ready Group in operations against North Vietnamese and Viet Cong (VC) forces.
Combat operations, interrupted in November for flood relief work, continued into the new year, 1965, and culminated in May off Chu Lai as she carried out her primary mission, vertical envelopment, for the first time in combat.

Returning to her homeport, Long Beach, California, after that operation, she transported Marine Aircraft Group 36 to Vietnam in August, and in February 1966 got underway for another tour in the combat zone.
Relieving Okinawa as flagship for the Amphibious Ready Group, she engaged the enemy in operations Jackstay, 26 March – 6 April, to clear the Rung Sat Special Zone of Viet Cong guerrillas, and Osage, 27 April – 4 May, to protect Vietnamese in the Phu Loc area from VC harassment.

Search and destroy missions against Viet Cong and People's Army of Vietnam units followed as Princeton provided transportation, medical evacuation, logistics and communication support for the amphibious operation Deckhouse I, 18 – 27 June, in the Song Cau district and the Song Cai river valley, then supported 1st Cavalry and 101st Airborne units engaged in Operation Nathan Hale to the south of the Deckhouse I area.
Operation Deckhouse II and support for Operation Hastings followed as Navy, Marine, and Army units again combined, this time to impede enemy infiltration from the DMZ.

After Operation Hastings, Princeton sailed for home, arriving on 2 September.
She deployed again to Vietnam from 30 January–19 June 1967, and again ranged along the coast.
In March, she assisted in countering an enemy threat to the Marine artillery base at Gio Linh and evacuated wounded from Con Thien.
In April, she participated in Operation Beacon Star, in the Khe Sanh area, and supported search and destroy operations in conjunction with Operation Shawnee.
In May, her helicopters lifted Marines to the DMZ to block enemy forces withdrawing across the Bến Hải River.

A much-needed overhaul followed Princeton's return to the west coast, and in May 1968 she again sailed west to Vietnam.
There, as flagship for Amphibious Ready Group Alpha, she provided amphibious assault carrier services for operations Fortress Attack III and IV, Proud Hunter, Swift Pursuit, and Eager Hunter.
In December, she returned to the United States and in April 1969 she was designated the prime recovery ship for Apollo 10, the lunar mission which paved the way for Apollo 11 and the first manned landing on the Moon.
Apollo 10 was recovered in the South Pacific on 26 May.
On 30 January 1970, Princeton was decommissioned and struck from the Naval Vessel Register, and sold for scrapping in May 1971.
In October 1964, Princeton exchanged WestPac training for the real thing as she returned to Vietnam and joined the Pacific Fleet's Ready Group in operations against North Vietnamese and Viet Cong (VC) forces. Combat operations, interrupted in November for flood relief work, continued into the new year, 1965, and culminated in May off Chu Lai as she carried out her primary mission, vertical envelopment, for the first time in combat.
Returning to her homeport, Long Beach, California, after that operation, she transported Marine Aircraft Group 36 to Vietnam in August, and in February 1966 got underway for another tour in the combat zone. Relieving Okinawa as flagship for the Amphibious Ready Group, she engaged the enemy in operations Jackstay, 26 March – 6 April, to clear the Rung Sat Special Zone of Viet Cong guerrillas, and Osage, 27 April – 4 May, to protect Vietnamese in the Phu Loc area from VC harassment.
Search and destroy missions against Viet Cong and People's Army of Vietnam units followed as Princeton provided transportation, medical evacuation, logistics and communication support for the amphibious operation Deckhouse I, 18 – 27 June, in the Song Cau district and the Song Cai river valley, then supported 1st Cavalry and 101st Airborne units engaged in Operation Nathan Hale to the south of the Deckhouse I area. Operation Deckhouse II and support for Operation Hastings followed as Navy, Marine, and Army units again combined, this time to impede enemy infiltration from the DMZ.
After Operation Hastings, Princeton sailed for home, arriving on 2 September. She deployed again to Vietnam from 30 January–19 June 1967, and again ranged along the coast. In March, she assisted in countering an enemy threat to the Marine artillery base at Gio Linh and evacuated wounded from Con Thien. In April, she participated in Operation Beacon Star, in the Khe Sanh area, and supported search and destroy operations in conjunction with Operation Shawnee. In May, her helicopters lifted Marines to the DMZ to block enemy forces withdrawing across the Bến Hải River.
A much-needed overhaul followed Princeton's return to the west coast, and in May 1968 she again sailed west to Vietnam. There, as flagship for Amphibious Ready Group Alpha, she provided amphibious assault carrier services for operations Fortress Attack III and IV, Proud Hunter, Swift Pursuit, and Eager Hunter. In December, she returned to the United States and in April 1969 she was designated the prime recovery ship for Apollo 10, the lunar mission which paved the way for Apollo 11 and the first manned landing on the Moon. Apollo 10 was recovered in the South Pacific on 26 May.
On 30 January 1970, Princeton was decommissioned and struck from the Naval Vessel Register, and sold for scrapping in May 1971.
USS Princeton (CV-37)