The Mountain railways of India are the railway lines that were built in the mountainous regions of India. The term mainly includes the narrow-gauge and metre-gauge railways in these regions but may also include some broad-gauge railways.

The Darjeeling Himalayan Railway, also known as the DHR or the Toy Train, is a 610 mm gauge railway that runs between New Jalpaiguri and Darjeeling in the Indian state of West Bengal. Built between 1879 and 1881, it is about 88 km (55 mi) long. It climbs from about 100 m (330 ft) above sea level at New Jalpaiguri to about 2,200 m (7,200 ft) at Darjeeling, using six zig zags and three loops to gain altitude. Ghum station is situated at an altitude of 2,258 metres (7,407 ft). Six diesel locomotives handle most of the scheduled service, with daily tourist trains from Darjeeling to Ghum – India's highest railway station – and the steam-hauled Red Panda service from Darjeeling to Kurseong. Steam-enthusiast specials are hauled by vintage British-built B-Class steam locomotives. The railway's headquarters are at Kurseong.