Line A may refer to:
A (Los Angeles Railway), a former streetcar service in California, United States A (New York City Subway service), in New York, United States Line A (Buenos Aires Underground), in Argentina Line A (Prague Metro), in the Czech Republic Line A (Rome Metro), in Italy Mexico City Metro Line A, in Mexico Santiago Metro Line A, a planned line in Chile Bilbao tram, in Bilbao, Spain, originally called Line A Réseau express métropolitain, designated as line A, a light metro in Greater Montreal, Quebec
See also A Line (disambiguation) A Train (disambiguation)