The South African Railways Class NG1 0-4-0T of 1900 was a narrow-gauge steam locomotive from the pre-Union era in Transvaal.

Under the Whyte notation for the classification of steam locomotives, 0-4-0 represents one of the simplest possible types, that with two axles and four coupled wheels, all of which are driven. The wheels on the earliest four-coupled locomotives were connected by a single gear wheel, but from 1825 the wheels were usually connected with coupling rods to form a single driven set.