大西部铁路（Great Western Railway）是英国铁路公司，铁路网联系伦敦西南部和英格兰西部和大部分威尔士地区。大西部铁路于1833年设立，于1835年国会法案通过，第一次列车于1838年行使。它由伊桑巴德·金德姆·布鲁内尔所设计，他选择了宽轨7英尺1/4（2140毫米）为轨距，但是从1854年开始，它也经营标准轨火车（1435毫米），最后宽轨火车服务在1892年开始营运。1921年铁路法通过之后，大西部铁路成为英国四大铁路公司之一。大西部铁路在1947年底被收归国有，成为英国铁路西部地区。

The Great Western Railway (GWR) was a British railway company that linked London with the midlands, the south-west and west of England and most of Wales. It was founded in 1833, received its enabling Act of Parliament in 1835 and ran its first trains in 1838. It was engineered by Isambard Kingdom Brunel, who chose a broad gauge of 7 ft (2,134 mm) but, from 1854, a series of amalgamations saw it also operate 4 ft 8 ⁄₂ in (1,435 mm) standard-gauge trains; the last broad-gauge services were operated in 1892. The GWR was the only company to keep its identity through the Railways Act 1921, which amalgamated it with the remaining independent railways within its territory, and it was finally merged at the end of 1947 when it was nationalised and became the Western Region of British Railways.