The United States Navy Sea, Air, and Land (SEAL) Teams, commonly known as Navy SEALs, are the United States Navy's primary special operations force and a component of the United States Naval Special Warfare Command. Among the SEALs' main functions are conducting small-unit special operation missions in maritime, jungle, urban, arctic, mountainous, and desert environments. SEALs are typically ordered to capture or kill high-level targets, or to gather intelligence behind enemy lines.

SEAL team personnel are hand-selected, highly trained, and highly proficient in unconventional warfare (UW), direct action (DA), and special reconnaissance (SR), among other tasks like sabotage, demolition, intelligence gathering, and hydrographic reconnaissance, training, and advising friendly militaries or other forces. All active SEALs are members of the U.S. Navy.

Although not formally founded until 1962, the modern-day U.S. Navy SEALs trace their roots to World War II. The United States Military recognized the need for the covert reconnaissance of landing beaches and coastal defenses. As a result, the joint Army, Marine Corps, and Navy Amphibious Scout and Raider School was established in 1942 at Fort Pierce, Florida. The Scouts and Raiders were formed in September of that year, just nine months after the attack on Pearl Harbor, from the Observer Group, a joint U.S. Army-Marine-Navy unit.

Recognizing the need for a beach reconnaissance force, a select group of Army and Navy personnel assembled at Amphibious Training Base (ATB) Little Creek, Virginia on 15 August 1942 to begin Amphibious Scouts and Raiders (Joint) training. The Scouts and Raiders' mission was to identify and reconnoiter the objective beach, maintain a position on the designated beach prior to a landing, and guide the assault waves to the landing beach. The unit was led by U.S. Army 1st Lieutenant Lloyd Peddicord as commanding officer, and Navy Ensign John Bell as executive officer. Navy Chief Petty Officers and sailors came from the boat pool at U. S. Naval Amphibious Training Base, Solomons, Maryland, and Army Raider personnel came from the 3rd and 9th Infantry Divisions. They trained at Little Creek until embarking for the North Africa campaign the following November. Operation Torch was launched in November 1942 off the Atlantic coast of French Morocco in North Africa.

The first group included Phil H. Bucklew, the "Father of Naval Special Warfare," after whom the Naval Special Warfare Center building is named. Commissioned in October 1942, this group saw combat in November 1942 during Operation Torch on the North African Coast. Scouts and Raiders also supported landings in Sicily, Salerno, Anzio, Normandy, and southern France.

The second group of Scouts and Raiders, code-named Special Service Unit No. 1, was established on 7 July 1943, as a joint and combined operations force. The first mission, in September 1943, was at Finschhafen in Papua New Guinea. Later operations were at Gasmata, Arawe, Cape Gloucester, and the east and south coasts of New Britain, all without any loss of personnel. Conflicts arose over operational matters, and all non-Navy personnel were reassigned. The unit, renamed 7th Amphibious Scouts, received a new mission, to go ashore with the assault boats, buoy channels, erect markers for the incoming craft, handle casualties, take offshore soundings, clear beach obstacles, and maintain voice communications linking the troops ashore, incoming boats and nearby ships. The 7th Amphibious Scouts conducted operations in the Pacific for the duration of the conflict, participating in more than 40 landings.

The third and final Scouts and Raiders organization operated in China. Scouts and Raiders were deployed to fight with the Sino-American Cooperative Organization (SACO). To help bolster the work of SACO, Admiral Ernest J. King ordered that 120 officers and 900 men be trained for "Amphibious Raider" at the Scout and Raider school at Fort Pierce, Florida. They formed the core of what was envisioned as a "guerrilla amphibious organization of Americans and Chinese operating from coastal waters, lakes, and rivers employing small steamboats and sampans." While most Amphibious Raider forces remained at Camp Knox in Calcutta, three of the groups saw active service. They conducted a survey of the upper Yangtze River in the spring of 1945 and, disguised as coolies, conducted a detailed three-month survey of the Chinese coast from Shanghai to Kitchioh Wan, near Hong Kong.

In September 1942, 17 Navy salvage personnel arrived at ATB Little Creek, Virginia for a week-long course in demolitions, explosive cable cutting, and commando raiding techniques. On 10 November 1942, the first combat demolition unit successfully cut cable and net barriers across the Wadi Sebou River during Operation Torch in North Africa. This enabled USS Dallas (DD-199) to traverse the water and insert U.S. Rangers who captured the Port Lyautey airdrome.