4 was the number assigned to two distinct streetcar lines operated by the Los Angeles Railway in Los Angeles, California.
4 was first assigned to a short turn service of the 3 Line. This operated from 1931 to 1935 when all operations along the route reverted to 3 Line service.
The number was later assigned to the Boyle Street Shuttle (previously line 31) beginning May 19, 1939. This service was short lived and ceased in October 1941.