Class 03
Class 03 may refer to:

British Rail Class 03, a class of post-war, British diesel-mechanical shunter,
DRG Class 03, a class of inter-war, German standard steam locomotive (Einheitslokomotive) for express train duties on lighter main lines. DRG Class 03.10, a streamlined, 3-cylinder development of the above DRG Class 03 built at the outset of World War II. See also
Class 3 (disambiguation)