Development of the Seasprite had been initiated during the late 1950s in response to a request from the United States Navy, calling for a suitably fast and compact naval helicopter for utility missions. Kaman's submission, internally designated as the K-20, was favourably evaluated, leading to the issuing of a contract for the construction of four prototypes and an initial batch of 12 production helicopters, designated as the HU2K-1. Beyond the U.S. Navy, the company had also made efforts to acquire other customers for export sales, in particular the Royal Canadian Navy; however, the initial interest of the Canadians was quelled as a result of Kaman's demand for price increases and the Seasprite performing below company projections during its sea trials. Due to its unsatisfactory performance, from 1968 onwards, the U.S. Navy's existing UH-2s were remanufactured from their originally-delivered single-engine arrangement to a more powerful twin-engine configuration.

During October 1970, the Seasprite was selected by the U.S. Navy as the platform for the interim Light Airborne Multi-Purpose System (LAMPS) helicopter, which resulted in greatly enhanced anti-submarine and anti-surface threat capabilities being developed and installed upon a new variant of the type, designated as the SH.2F. Accordingly, during the 1970s and 1980s, the majority of the existing UH-2 helicopters were remanufactured into the improved SH-2F model. In this configuration, the Seasprite extended and increased shipboard sensor and weapon capabilities against several types of enemy threats, including submarines of all types, surface ships and patrol craft that may be armed with anti-ship missiles.

The Seasprite served for many decades with the U.S. Navy. Highlights of its service life included operations during the lengthy Vietnam War, in which the type was primarily used to rescue downed friendly aircrews within the theatre of operations, and its deployment during the Gulf War, where Seasprites conducted combat support and surface warfare operations against hostile Iraqi forces. In more routine operations, the Seasprite was operated in a number of roles, including anti-submarine warfare (ASW), search and rescue (SAR), utility and plane guard (the latter being performed when on attachment to aircraft carriers). The type was finally withdrawn during 2001 when the last examples of the final variant, known as the SH-2G Super Seasprite were retired. During the 1990s and 2000s, ex-U.S. Navy Seasprites were offered to various nations as a form of foreign aid, which typically met with mixed interest and a limited uptake.

Below is a partial list of airframes that survived military service.