The County Donegal Railways Joint Committee operated an extensive 3 ft (914 mm) narrow gauge railway system serving County Donegal, Ireland, from 1906 until 1960.

The lines inherited by the Joint Committee totalled 106 miles (171 km) and were: By 1912 the company owned the following assets:[1] The Strabane to Derry line was completely owned by the Midland Railway Northern Counties Committee, although it was operated by the CDRJC.

[3] The Joint Committee opened the Strabane and Letterkenny Railway on 1 January 1909, bringing the total mileage operated by the company to 124.5 miles (200.4 km).

[4] Under the management of Henry Forbes, traffic superintendent from 1910 to 1943, the County Donegal Railways became pioneers in the use of diesel traction.

Eight articulated diesel railcars were constructed by Walker Brothers of Wigan between 1934 and 1951, by which time virtually all passenger services were operated by diesel railcar, being much cheaper to operate than conventional steam trains.

The railcars could only be driven from one end and had to be turned on a turntable to make a return journey.

A diesel locomotive named Phoenix (converted from a steam locomotive) was also used, but due to its noisy operation and slow speed (top speed of 27 mph or 43 km/h), it spent most of its career shunting, travelling 204,577 miles (329,235 km) during its working life.

After the closure of the railway, it continued to operate as a road freight and bus company until 10 July 1971 when it was taken over by CIÉ.

Part of the line, which runs alongside Lough Finn near Fintown, has been re-laid as a tourist railway.

[8] The Donegal Railway Heritage Centre has been established and contains historic details and artefacts of the CDRJC.

[9] St. Connell's Museum, in Glenties has an extensive display of items from the railway.

[10] The Foyle Valley Railway in Derry houses numerous CDRJC artefacts.