The Class 03 steam engines were standard express train locomotives (Einheitslokomotiven) in service with the Deutsche Reichsbahn.

The Class 03 engines were built between 1930 and 1938 as express train locomotives for routes that were only suitable for axle loads of up to 18 tonnes.

298 examples of this engine, whose construction was based on the Class 01, were built by the firms of Borsig, Krupp, Henschel, and Schwartzkopff.

Locomotive number 03 154 was equipped with a parabolic smokebox door, a tapered driver's cab and driving gear cover plates.

Number 03 193 was given a wine-red, streamlined, full covering and a 2′3 T 37 St tender, in order to replace the Class 05.