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.

The SLRV was purchased by the public transportation operators of Boston and San Francisco; in service by 1976, the US SLRV proved to be unreliable and scrapping started as early as 1987, but the SLRV were not completely replaced in both systems until 2007. Although the SLRV itself was not successful due to poor reliability, it did set the general size and configuration for succeeding LRVs in the United States.