The JGR Class 5100 (5100形) was a type of 4-4-0 steam locomotive used on Japanese Government Railways. The two locomotives, numbered 18 and 20, were built by Kitson and Company in the United Kingdom in 1874 as 0-6-0 locomotives of the later JGR Class 7010. They were rebuilt into 4-4-0 wheel arrangement passenger locomotives at Kobe in 1876. In 1909, the two locomotives were classified Class 5100, becoming numbers 5100 and 5101.[2]