G
- Ganymede (Greek mythology: Ganymede)
- GWR Fire Fly class 2-2-2 (1842 - 1878)
- Gazelle (Fast animal: Gazelle)
- GWR Sun class 2-2-2 (1841 - 1879)
- SDR Eagle class 4-4-0ST (1859 - 1865)
- Gemini (Zodiac: Gemini)
- GWR Leo class 2-4-0 (1841 - 1866)
- Geryon (Greek mythology: Geryon)
- GWR Standard Goods 0-6-0 (1854 - 1876)
- Giaour (Literature: The Giaour)
- GWR Standard Goods 0-6-0 (1852 - 1880)
- Giraffe (Animal: Giraffe)
- GWR Sun class 2-2-2 (1841 - 1872)
- SDR Eagle class 4-4-0ST (1859 - 1877)
- Gladiator (Power: Gladiator)
- GWR Standard Goods 0-6-0 (1861 - 1877)
- Gloucester (Geography: Gloucester)
- BGR 2-2-2 (1844 - 1855)
- GWR Swindon class 0-6-0 (1866 - 1873)
- Glyncorrwg (Geography: Glyncorrwg)
- SWMR 0-4-2ST (1864 - 1872)
- Gnat (Insect: Gnat)
- GWR Metropolitan class 2-4-0T (1862 - 1874)
- Goat (Animal: Goat)
- SDR Owl class 0-4-0WT (1873 - 1893)
- Goliah (Biblical: Goliath)
- GWR Hercules class 0-6-0 (1842 - 1871)
- SDR Tornado class 0-6-0ST (1855 - 1885)
- Gooch (Famous engineer: Daniel Gooch)
- GWR Hawthorn class 2-4-0 (1865 - 1892)
- Gorgon (Greek mythology: Gorgon)
- GWR Fire Fly class 2-2-2 (1841 - 1878)
- SDR Gorgon class 4-4-0ST (1866 - 1892)
- Great Britain (Geography: Great Britain)
- GWR Iron Duke class 4-2-2 (1847 - 1880)
- GWR Rover class 4-2-2 (1880 - 1892)
- Great Western (Railway: Great Western Railway)
- GWR 2-2-2 (1846)
- GWR Iron Duke class 4-2-2 (1846 - 1870)
- GWR Rover class 4-2-2 (1888 - 1892)
- Greyhound (Fast animal: Greyhound)
- GWR Fire Fly class 2-2-2 (1841 - 1866)
- Gyfeillon
- GWR Standard Goods 0-6-0 (1856 - 1879)
Read more about this topic: List Of Broad Gauge (7 Feet) Railway Locomotive Names