The Oswestry and Newtown Railway was a British railway company that built a line between Oswestry in Shropshire and Newtown Montgomeryshire, now Powys. The line opened in stages in 1860 and 1861. It was conceived to open up the area to rail transport, when local opinion formed the view that the trunk railway companies would not do so. Subscription money for the construction proved very difficult to generate. It was the action of a contractor partnership, Davies and Savin, in agreeing to accept shares as the majority of their payment for construction work, that saved the company from failure.
Forming a local network with other local concerns, the O&NR amalgamated with them, forming the Cambrian Railways, in 1863. The industry in the area was not buoyant and hoped-for long-distance traffic did not materialise, although the development of Aberystwyth as a resort provided a useful benefit. The railway connected to the emerging national network at Oswestry, but the later connection of the Shrewsbury and Welshpool Railway abstracted traffic from the northern part of the system. A grim event took place in 1921 near Abermule, when there was a head-on collision on the single line, due to slack operating disciplines. The collision resulted in seventeen deaths.
As social and travel habits changed in the 1960s, the line's remaining core income was badly reduced, and for a time widespread closure was a possibility. In fact the Shrewsbury connection to Aberystwyth and the coastal line to Pwllheli were retained, but the section from Oswestry to Buttington closed in 1965. The main line from Buttington to Newtown continues in use as part of a passenger connection to Aberystwyth and the coast.