The Tasmanian Government Railways K class was a class of 0-4-0+0-4-0 Garratt locomotives operated by the Tasmanian Government Railways from 1909 – the first Garratt locomotives built.

Under the Whyte notation for the classification of steam locomotives by wheel arrangement, the 0-4-0+0-4-0 is an articulated locomotive of the Garratt type. The wheel arrangement is effectively two 0-4-0 locomotives operating back-to-back or face-to-face, with the boiler and cab suspended between the two power units. Each power unit has no leading wheels, four powered and coupled driving wheels on two axles and no trailing wheels. A similar arrangement exists for Mallet, Meyer and Fairlie locomotives, but is referred to as 0-4-4-0.