On 4 January 1956 she steamed for a tour of duty in the Mediterranean as the flagship of Vice Admiral Ralph A. Ofstie, Commander Sixth Fleet.

In March 1960, while steaming 75 miles northeast of Sicily, Newport News was ordered to proceed to Agadir, Morocco, to render assistance to the survivors of the 1960 earthquake.

After the assassination of General Rafael Trujillo and the resulting instability in Santo Domingo, Newport News was underway on short notice on 4 June 1961, and proceeded to a station in international waters off the Dominican Republic to await further orders.

Newport News' berthing and communications facilities were modified in the winter of 1962 to accommodate Commander United States Second Fleet and his staff.

Within a month after return to Norfolk, Newport News was underway on 22 October as the flagship of the Atlantic Fleet for the Cuban Missile Crisis, with USS Leary as her destroyer escort.

When the Dominican Republic crisis of 1965 developed, Newport News sortied from Norfolk on 29 April for Santo Domingo, where she was flagship for Commander Joint Task Force 122.

Newport News remained on station off Santo Domingo until 7 May 1965 when JTF 122 was dissolved, and command was shifted to the Army ashore in the Dominican Republic.

That night, at 2300, she fired her eight-inch guns for the first time in anger against shore targets in North Vietnam as part of Operation Sea Dragon.

According to spotters, Newport News sank 17 waterborne logistics craft, damaged another 14 and destroyed several enemy bunkers and radar sites, bridges, barges, trucks and roads.

This encounter led to forward observers to nickname Newport News "The Gray Ghost from the East Coast," a moniker she retained throughout her three Vietnam deployments.

Following an extensive yard overhaul period to prepare her for further combat operations, on 21 November 1968 Newport News departed Norfolk to commence a second deployment to Vietnam.

Combat operations during this tour commenced on 25 December 1968, focused on providing naval gunfire support to the 7th and 9th ARVN in Vĩnh Bình Province and the DMZ.

Newport News departed Da Nang on 3 June 1969, via San Francisco and the Panama Canal, to arrive at her homeport in Norfolk, Virginia, in early July.

"Along with 64 other aircraft carriers, cruisers, destroyers and supply ships of the Seventh Fleet—the biggest armada organized since World War II, Navy officers say—the Newport News is part of Operation Linebacker, the Nixon Administration's air and naval campaign to prevent North Vietnamese supplies from getting to South Vietnam.

[7] At 1 a.m. on 1 October 1972, while in action off the Demilitarized Zone, Newport News sustained an in-bore explosion in her center 8-inch gun of number two turret.

This would result in her becoming the United States Second Fleet flagship for most of the rest of her career, save for her gunfire support stints during the Vietnam War.

She spent her later years as a member of the Philadelphia Naval Shipyard's Mothball Fleet and was sold for scrap in New Orleans, Louisiana, on 25 February 1993 during the Clinton Administration.