A Kleinlokomotive or Kleinlok (literally: "small locomotive"; plural: Kleinlokomotiven or Kleinloks) is a German locomotive of small size and low power for light shunting duties at railway stations and on industrial railways. Most are powered by diesel engines, but Kleinloks with steam, petrol, or electric engines were also produced.
After testing several trials locomotives, the Deutsche Reichsbahn (DRG) placed various types of such locomotives into service from 1930 onwards. Industrial lines and railway workshops generally procured engines of the same design.
In Switzerland Kleinlokomotiven were used as light rail motor tractors.