The Sonning Cutting railway accident occurred during the early hours of 24 December 1841 in the Sonning Cutting through Sonning Hill, near Reading, Berkshire. A Great Western Railway (GWR) luggage train travelling from London Paddington to Bristol Temple Meads station entered Sonning Cutting. The train was made up of the broad-gauge locomotive Hecla, a tender, three third-class passenger carriages, and some heavily laden goods waggons. The passenger carriages were between the tender and the goods waggons.

The Great Western Railway (GWR) was a British railway company that linked London with the southwest, west and West Midlands of England and most of Wales. It was founded in 1833, received its enabling act of Parliament on 31 August 1835 and ran its first trains in 1838 with the initial route completed between London and Bristol in 1841. It was engineered by Isambard Kingdom Brunel, who chose a broad gauge of 7 ft —later slightly widened to 7 ft 1⁄4 in —but, from 1854, a series of amalgamations saw it also operate 4 ft 8+1⁄2 in standard-gauge trains; the last broad-gauge services were operated in 1892.