The Mountain Railways of India refers to the five railway lines constructed during the British period in the mountains of India in the 19th and early 20th century. Three out of these five railways, the Darjeeling Himalayan Railway, the Kalka-Shimla Railway and the Kangra Valley Railway, are located in the rugged hill regions of the Himalayas of Northern India.

The Darjeeling Himalayan Railway, opened in 1881, was the first, and is still the most outstanding, example of a hill passenger railway.

The construction of the Nilgiri Mountain Railway, a 46-km long metre-gauge single-track railway in Tamil Nadu State was completed in 1908. This railway, scaling an elevation of 326 m to 2,203 m, represented the latest technology of the time.

The Kalka Shimla Railway, a 96-km long, single track working rail link built in the mid-19th century to provide a service to the highland town of Shimla is emblematic of the technical and material efforts to dis-enclave mountain populations through the railway.

All the five railway lines are still operational and connect to important hill resorts, from foot hills, winding through rugged and scenic mountainous terrains.