S
- Sagittarius (Zodiac: Sagittarius)
- GWR Leo class 2-4-0 (1842 - 1871)
- Salus (Greek mythology: Salus)
- GWR Standard Goods 0-6-0 (1854 - 1877)
- Sampson (Biblical: Sampson)
- GWR Hercules class 0-6-0 (1842 - 1870)
- SDR Tornado class 0-6-0ST (1855 - 1884)
- Sappho (Greek personality: Sappho)
- GWR Bogie class 4-4-0ST (1854 - 1873)
- Saturn (Roman mythology: Saturn)
- GWR Fire Fly class 2-2-2 (1841 - 1878)
- Saunders
- GWR Sir Watkin class 0-6-0T (1866 - 1872)
- SDR 0-6-0ST (1872 - 1892)
- Scorpio (Zodiac: Scorpio)
- GWR Leo class 2-4-0 (1841 - 1872)
- Sebastopol (British battle: Sebastopol)
- GWR Iron Duke class 4-2-2 (1855 - 1880)
- GWR Rover class 4-2-2 (1880 - 1892)
- Sedley
- SDR Gorgon class 4-4-0ST (1866 - 1885)
- Seneca (Roman personality: Seneca the Younger)
- GWR Bogie class 4-4-0ST (1854 - 1872)
- Severn (Geography: River Severn)
- GWR Standard Goods 0-6-0 (1857 - 1873)
- Severus (Roman personality: Septimus Severus)
- GWR Standard Goods 0-6-0 (1861 - 1878)
- Shah (Leader of people: Shah)
- GWR Metropolitan class 2-4-0T (1862 - 1872)
- Shamrock (Flower: Shamrock)
- GWR Metropolitan class 2-4-0T (1863 - 1877)
- Shannon (Geography: River Shannon)
- GWR Standard Goods 0-6-0 (1857 - 1880)
- Sharp (Famous engineer: Thomas Sharp)
- GWR Hawthorn class 2-4-0 (1866 - 1887)
- Shrewsbury (Geography: Shrewsbury)
- GWR Swindon class 0-6-0 (1866 - 1872)
- Shooting Star
- GWR Star class 2-2-2 (1841 - 1871)
- Sibyl (Greek mythology: Sibyl)
- GWR Standard Goods 0-6-0 (1854 - 1878)
- Sir Watkin
- GWR Sir Watkin class 0-6-0T (1866 - 1892)
- Sirius (Star: Sirius)
- GWR Standard Goods 0-6-0 (1861 - 1880)
- Slaughter (Famous engineer: Edward Slaughter)
- GWR Hawthorn class 2-4-0 (1865)
- Smeaton (Famous engineer: John Smeaton)
- GWR Victoria class 2-4-0 (1863 - 1877)
- Snake (Animal: Snake)
- GWR Haigh Foundry 2-2-2 (1838 - 1869)
- Sol (Sun: Sol)
- SDR Gorgon class 4-4-0ST (1866 - 1892)
- Sphinx (Egyptian mythology: Sphinx)
- GWR Standard Goods 0-6-0 (1854 - 1873)
- Spit Fire
- GWR Fire Fly class 2-2-2 (1840 - 1878)
- Stag (Fast animal: Stag)
- SDR Leopard class 4-4-0ST (1872 - 1893)
- Star
- NDR 2-2-2 (1855 - 1870)
- Statius (Roman personality: Statius)
- GWR Bogie class 4-4-0ST (1855 - 1871)
- Stentor (Greek personality: Stentor)
- GWR Fire Fly class 2-2-2 (1842 - 1867)
- Stephenson (Famous engineer: George Stephenson)
- GWR Victoria class 2-4-0 (1863 - 1878)
- Steropes (Greek mythology: Steropes)
- GWR Pyracmon class 0-6-0 (1848 - 1871)
- Stewart (Famous engineer: Charles Stewart)
- GWR Hawthorn class 2-4-0 (1866 - 1877)
- GWR Hawthorn class 2-4-0T (1877 - 1892)
- Stiletto
- GWR Sun class 2-2-2 (1841 - 1870)
- Stromboli (Geography: Stromboli)
- GWR Leo class 2-4-0 (1841 - 1870)
- SDR 0-6-0ST (1872 - 1889)
- Stroud (Geography: Stroud)
- BGR 2-2-2 (1844 - 1855)
- Sultan (Leader of people: Sultan)
- GWR Iron Duke class 4-2-2 (1847 - 1874)
- GWR Rover class 4-2-2 (1876 - 1892)
- Sun
- GWR Sun class 2-2-2 (1840 - 1873)
- Sunbeam
- GWR Sun class 2-2-2 (1840 - 1870)
- Swallow (Fast bird: Swallow)
- GWR Iron Duke class 4-2-2 (1849 - 1871)
- GWR Rover class 4-2-2 (1871 - 1892)
- Swindon (Geography: Swindon)
- GWR Swindon class 0-6-0 (1865 - 1874)
- Sylla
- GWR Standard Goods 0-6-0 (1862 - 1878)
- Sylph
- GWR Prince class 2-2-2 (1847 - 1870)
Read more about this topic: List Of Broad Gauge (7 Feet) Railway Locomotive Names