The US Standard Light Rail Vehicle (SLRV) was a light rail vehicle (LRV) built by Boeing Vertol in the 1970s. The Urban Mass Transportation Administration (UMTA) of the United States Department of Transportation (USDOT) promoted it as a standardized vehicle for U.S. cities. Part of a series of defense conversion projects in the waning days of the Vietnam War, the SLRV was seen as both a replacement for older PCC streetcars in many cities and as a catalyst for cities to construct new light rail systems. The US SLRV was marketed as and is popularly known as the Boeing LRV or SLRV, and should not be confused with their prior lunar roving vehicles for NASA.

Light rail transit (LRT) is a form of passenger urban rail transit characterized by a combination of tram and rapid transit features. While its rolling stock is similar to that of a traditional tram, it operates at a higher capacity and speed and often on an exclusive right-of-way. In many cities, light rail transit systems more closely resemble, and are therefore indistinguishable from, traditional underground or at-grade subways and heavy-rail metros.