The Great Southern and Western Railway (GS&WR) was an Irish gauge railway company in Ireland from 1844 until 1924. The GS&WR grew by building lines and making a series of takeovers, until in the late 19th and early 20th centuries it was the largest of Ireland's "Big Four" railway networks. At its peak the GS&WR had an 1,100-mile (1,800 km) network, of which 240 miles (390 km) were double track.
- Country
- United Kingdom of Great Britain and Ireland, Irish Free State
- Inception
- 1844
