C1 class or Class C1 may refer to:
C1-class Melbourne tram Finnish Steam Locomotive Class C1, 0-6-0 steam locomotives GNR Class C1 (large boiler), 4-4-2 steam locomotives GNR Class C1 (small boiler), 4-4-2 steam locomotives LB&SCR C1 class, 0-6-0 steam locomotives NER Class C1, 0-6-0 steam locomotives LNWR Class C1, 0-8-0 steam locomotives Pennsylvania Railroad class C1, 0-8-0 steam locomotives