Naval Support Activity Danang or NSA Danang was a United States Navy logistics support organization located in Danang, South Vietnam active from October 1965 to April 1972.

In March 1965 when United States Marine Corps combat troops landed at Danang, the support establishment was rudimentary. The port of Danang contained only three small piers, three Landing Ship, Tank (LST) ramps and a stone quay that were inaccessible to oceangoing vessels; even smaller craft had trouble approaching. The scarcity of lighterage and the heavy weather that often buffeted the harbor made ship-to-craft cargo transfers hazardous and inefficient. Warehouses, open storage areas, cargo handling equipment, and good exit routes from the port were limited. From March to July 1965, III Marine Amphibious Force (III MAF) troops delivered supplies to the units in the field while the Seventh Fleet ran port operations. Soon, the fleet dispatched Naval Beach Group One Cargo Handling Battalions 1 and 2, nucleus port crew, Mine Force, Service Force, Underwater Demolition Team, and Explosive Ordnance Disposal (EOD) units to Danang. In addition, the Navy took charge of the offloading, storage and delivery of supplies common to all the allied forces in I Corps. Additional responsibilities included harbor defense and the transshipment of cargo to the smaller ports in the region. The fleet also managed logistic operations at these locations.

U.S. NSA Danang was officially established on 15 October 1965 under the operational control of Commander, III MAF. During the next several years, the command created subordinate NSA detachments at Chu Lai, Huế, Tân Mỹ, Đông Hà, Cửa Việt, Phú Bài and Sa Huỳnh. These detachments decentralized the support function and improved the logistic flow.

During 1965 the logistic operation at Danang suffered from lack of suitable or sufficient harbor craft, cargo handling equipment, and port personnel. Management and planning of the logistic flow needed refinement, as ships arrived en masse with cargo improperly stowed and packaged. Storage areas ashore were limited by space and access. Finally, the harsh northeast monsoon made cargo operations at Danang and throughout I Corps hazardous and difficult during the winter months.

In November 1965 500 men moved into the old French Army camp, Camp Tien Sha (Tiên Sa) at the foot of Monkey Mountain. The camp was quickly expanded to include 25 new barracks able to accommodate an additional 1,700 men, together with a barber shop, post exchange and milk plant. NSA Danang originally operated from a commercial pier on the city side of the Hàn River and this "Museum Ramp" (16°03′00″N 108°13′28″E / 16.05°N 108.2245°E / 16.05; 108.2245) near the Cham Museum began operation in November 1965 off-loading Landing Craft Utility (LCUs) and LSTs.

On 1 April 1966 Naval Forces Vietnam was established in Saigon and assumed control of NSA Danang from III MAF.

In July 1966 the "Bridge Cargo Ramp" (16°03′07″N 108°13′52″E / 16.052°N 108.231°E / 16.052; 108.231) began operations increasing NSA's supply capability.

In August 1967, the headquarters of NSA Danang was moved from downtown Danang to Camp Tien Sha.