USS Pueblo (AGER-2) is a Banner-class technical research ship, placed into service during World War II, then converted to a spy ship in 1967 by the United States Navy. She gathered intelligence and oceanographic information, monitoring electronic and radio signals from North Korea. On 23 January 1968, the ship was attacked and captured by a North Korean vessel, in what became known as the "Pueblo incident".

The seizure of the U.S. Navy ship and her 83 crew members, one of whom was killed in the attack, came less than a week after President Lyndon B. Johnson's State of the Union address to the United States Congress, a week before the start of the Tet Offensive in South Vietnam during the Vietnam War and three days after 31 men of North Korea's KPA Unit 124 had crossed the Korean Demilitarized Zone (DMZ) and killed 26 South Koreans and 4 Americans in an attempt to attack the South Korean Blue House (executive mansion) in the capital Seoul. The taking of Pueblo and the abuse and torture of her crew during the next eleven months became a major Cold War incident, raising tensions between western and eastern powers.

North Korea stated that Pueblo deliberately entered their territorial waters 7.6 nautical miles (14 km) away from Ryo Island, and that the logbook shows that they intruded several times. However, the United States maintained that the vessel was in international waters at the time of the incident and that any purported evidence supplied by North Korea to support its statements was fabricated. Pueblo remains held in North Korea, officially a commissioned vessel of the United States Navy.

Since early 2013, the ship has been moored along the Pothonggang Canal in Pyongyang and is displayed there as a museum ship at the Victorious War Museum. Pueblo is the only ship of the U.S. Navy still on the commissioned roster and held captive.

The ship was launched at the Kewaunee Shipbuilding and Engineering Company in Kewaunee, Wisconsin, on 16 April 1944, as the United States Army Freight and Passenger (FP) FP-344. The Army later redesignated the FP vessels as Freight and Supply changing the designation to FS-344. The ship, commissioned at New Orleans on 7 April 1945, served as a Coast Guard–manned Army vessel used for training civilians for the Army. Her first commanding officer was Lt. J. R. Choate, USCGR, succeeded by Lt. J.G. Marvin B. Barker, USCGR, on 12 September 1945. FS-344 was placed out of service in 1954.

In 1964 the Department of Defense became interested in having smaller, less expensive, more flexible and responsive signals intelligence collection vessels than the existing AGTR and T-AG vessels. The mothballed light cargo ships were the most suitable existing DOD ships, and one was converted to USS Banner in 1964 and began operations in 1965. Banner's mission was to surveil high-frequency electronic emissions with line-of-sight propagation requiring operating closer to shore than previous intelligence gathering missions. Banner was unarmed, but the crew were issued five M1911 pistols and three M1 Garand rifles. Banner was confronted by Soviet Navy ships while operating off the Pacific coast of the Soviet Union. These ships would sometimes display international signal flags meaning: "Heave to or I will fire," but Banner kept steaming with scrupulous attention to International Regulations for Preventing Collisions at Sea. Soviet recognition of possible American reciprocity against Soviet ships on similar missions discouraged attacks.

FS-344 was transferred to the United States Navy on 12 April 1966 and was renamed USS Pueblo (AKL-44) after Pueblo and Pueblo County, Colorado on 18 June. Initially, she was classified as a light cargo ship for basic refitting at Puget Sound Naval Shipyard during 1966. As Pueblo was prepared under a non-secret cover as a light cargo ship, the general crew staffing and training was on this basis, with 44% having never been to sea when first assigned. Installation of signals intelligence equipment, at a cost of $1.5 million, was delayed to 1967 for budgetary reasons, resuming service as what is colloquially known as a "spy ship" and redesignated AGER-2 on 13 May 1967. The limited budget for conversion caused disapproval of several improvements requested by the prospective commanding officer, Lloyd Bucher. Requested engine overhaul was denied despite Banner's experience of drifting for two days unable to communicate following failure of both engines on patrol. A requested emergency scuttling system was denied, and Bucher was subsequently unable to obtain explosives for demolition charges. Replacement of burn barrels with a fuel-fed incinerator to allow speedy destruction of classified documents was denied. After Bucher's subsequent request to reduce the ship's library of classified publications was similarly denied, he was able to purchase a less capable incinerator using some discretionary funds intended for crew comfort. Following the USS Liberty incident on 8 June, Vice Chief of Naval Operations (VCNO) Horacio Rivero Jr. ordered that no Navy ship would operate without adequate means of defending itself. VCNO staff directed the shipyard to install a 3-inch/50-caliber gun on Pueblo's main deck with provisions for ammunition storage, but Bucher successfully argued against such installation because of reduced ship stability by addition of weight above the main deck. After testing and deficiency rework Pueblo sailed from the shipyard on 11 September 1967 to San Diego for shake-down training.

When the unarmed Pueblo reached the U.S. Navy base at Yokosuka, Japan, the commander of United States Naval Forces Japan directed the ship to take two M2 Browning .50 caliber machine guns as a substitute for the missing deck gun. In the limited time available for training, ten of the ship's crew fired five rounds each. Bucher opted to mount these guns in exposed positions on the bow and stern to keep them as far as possible from his position on the bridge. These positions eliminated possible use of the ship's superstructure to protect the gunners and conceal the guns and ammunition service lockers. The exposed guns, with no nearby ammunition supply, were disguised under canvas covers which became rigid with frozen spray.