The Lockheed S-3 Viking was developed as a replacement for the S-2 Tracker as the principal anti-submarine aircraft for service on board the US Navy's carrier fleet. It was designed in collaboration with Vought (LTV) for the airframe and Univac for the ASW systems and the result was highly satisfactory especially due to its abilty to carry a wide array of sensors and equipment in such a small aircraft (a necessity due to the nature of carrier operation). Among these are are an advanced search radar, an extendable Magnetic Anomaly Detector (MAD) boom in the rear and an internal bay capable of carrying torpedos, mines, bombs and depth charges in addition to a pair of external hardpoints for anti-ship missiles and rockets. With the demise of the Soviet submarine threat, S-3s have been readapted for other roles such as surveillance, anti-surface warfare and aerial refueling although they are expected to be fully retired from service by the end of the decade.

First flight of the development YS-3A was on 21 January 1972, they entered service with the USN as the S-3A two years later. A major upgrade resulted in the S-3B, capable of carrying the Harpoon anti-ship missile and also receiving a major improvement to sensors and systems; the grand majority of S-3As were eventually converted to this standard. Other variants include the ES-3A electronic intelligence and warfare platform as well as a few demonstration examples of the US-3A (Carrier Onboard Delivery or COD transports) and KC-3A tanker, neither of which ever entered production.