Saint Mary's Street station is a surface light rail stop on the MBTA Green Line C branch, located just west of the intersection of Beacon Street and Park Drive in the northeastern tip of Brookline, Massachusetts. Like all surface stops on the line, Saint Mary's Street has two side platforms serving two tracks. The station is accessible. With just over 1,500 daily boardings by a 2011 count, Saint Mary's Street is the second-busiest stop on the C branch, behind only Coolidge Corner.