3 ft gauge railways in the United Kingdom

A list of 3 ft (914 mm) narrow-gauge railways in the United Kingdom.

The worldwide usage of locomotives on railways, including 3 ft (914 mm) gauge railways, has its origins in the United Kingdom in the early 19th century during the Industrial Revolution.

In fact, in 1802, a 3 ft gauge plateway-type railway owned by the Coalbrookdale Company in England became the first railway in the world to have a locomotive designed and built for it.

The locomotive's designer, Richard Trevithick, is credited with making the first recorded successful demonstration of a locomotive on rails (in 1804 on a different railway in Wales).

3 ft gauge locomotive-powered railways, along with other narrow-gauge railways of varying widths, would later become one of the most common railway gauges chosen for short-distance lines in the British Isles, such as those found in mines and industrial sites (see table below).