USS Liberty (AGTR-5) was a Belmont-class technical research ship (an electronic spying ship) that is notable for coming under attack from the Israel Defense Forces during the 1967 Six-Day War. She was originally built and served in World War II as a VC2-S-AP3 type Victory cargo ship named SS Simmons Victory. Her keel was laid down on 23 February 1945 at Oregon Shipbuilding Corporation of Portland, Oregon.

In 1967, Israeli air force and naval units attacked the research ship during the Six-Day War. Israel later apologized for the attack, stating it had mistaken Liberty for an Egyptian ship, although the reason for the attack has been disputed. Liberty would eventually be decommissioned sometime after the attack and was sold for scrapping in 1973 as she had been damaged beyond feasible repair.

Her keel was laid down on 23 February 1945, under a Maritime Commission contract at Oregon Shipbuilding Corporation of Portland, Oregon. She entered service as a VC2-S-AP3 type Victory cargo ship named SS Simmons Victory, named after Simmons College in Boston, Massachusetts.

The ship was delivered to the War Shipping Administration on 4 May 1945. The next day, she was transferred to the "Coastwise -Pacific Far East Line" and designated as a "Fleet Issue Ship". Her complement included a 17-man Navy Armed Guard detachment to operate the ship's gun battery; a three- or four-man communication liaison detachment; and 16 Navy sailors serving as "winchmen and hatchmen".

Simmons Victory was tasked with delivering ammunition, which was loaded at the San Francisco-Suisun Bay area navy munitions depot at Port Chicago for Operation Downfall, the planned invasion of Japan. According to Harry Morgan, who served as an engineer on the ship, Simmons Victory arrived in the Philippines about six weeks before V-E Day on 8 May 1945. She made one trip north in support of Operation Downfall and returned to the Philippines. She was in Leyte Gulf when Japan surrendered on 15 August 1945.

Simmons Victory departed Leyte Gulf on 6 October 1945, en route to the US West Coast via Eniwetok, and dumped ammunition at sea two days later. She arrived in San Francisco on 3 November 1945 and departed for the US east coast on 9 December 1945, reaching New York on Christmas Day, 1945. Her 5-inch, 3-inch, and 20-mm guns were removed there on 9 January 1946.

From December 1946 until 1963, the ship moved back and forth several times from commercial charters as a break bulk cargo carrier to stints in the National Defense Reserve Fleet (being twice berthed in the Hudson River). Most notably during this time, she made nine trips to the Far East between November 1950 and December 1952 during the Korean War "to equip American troops fighting communist North Korea" in the Military Sea Transportation Service. On 11 June 1958, Simmons Victory once again entered the National Defense Reserve Fleet, being berthed this time at Olympia, Washington, where she remained until 1963.

In February 1963, the US Navy acquired Simmons Victory and converted her to a "Miscellaneous Auxiliary" ship at Willamette Iron and Steel of Portland. On 8 June, the vessel was renamed USS Liberty and given the hull classification symbol AG-168. On 1 April 1964, she was reclassified a Technical Research Ship, and given the radio call sign AGTR-5. She was commissioned at Puget Sound Naval Shipyard in Bremerton, Washington, in December 1964.