Line 15 may refer to:
China Line 15 (Beijing Subway), in China , in China Line 15 (Shanghai Metro), in China Line 15 (Xi'an Metro), in China
Other countries Line 15 (Paris Metro), in France, under construction Line 15 (São Paulo Metro), in Brazil Helsinki light rail line 15, in Finland Mascouche line, also designated as line 15, a commuter rail service in Greater Montreal, Quebec
See also List of public transport routes numbered 15