Class 78 may refer to:
DRG Class 78, a German 4-6-4T tank locomotive class operated by the Deutsche Reichsbahn and Deutsche Bundesbahn comprising: Class 78.0-5: Prussian T 18, Württemberg T 18 Class 78.6: BBÖ 729 DB Class 78.10: DB rebuild from the DRG Class 38.10-40