| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 261 | Fynbar | Celtic | Blond. | M | |
| 262 | Gall | Celtic | Stranger. | M | |
| 263 | Galvin | Celtic | Sparrow. | M | |
| 264 | Galvyn | Celtic | Sparrow. | M | |
| 265 | Gawain | Celtic | From Arthurian legend. | M | |
| 266 | Gervase | Celtic | Servant spear. This name is derived from combining an Old Gcrman name meaning spear, and the Celtic word for servant. Famous bearer: martyr St Gervase who died in Milan. | M | |
| 267 | Gildas | Celtic | Serves God. | M | |
| 268 | Gilmore | Celtic | Serves Mary. | M | |
| 269 | Gilroy | Celtic | Serves the red haired lord. | M | |
| 270 | Glen | Celtic | From the valley. | M | |
| 271 | Glenn | Celtic | From the valley. | M | |
| 272 | Glifieu | Celtic | Mythical son of Taran. | M | |
| 273 | Glyn | Celtic | From the valley. | M | |
| 274 | Gorsedd | Celtic | From Arbeth. | M | |
| 275 | Gruddieu | Celtic | Mythical son of Muriuel. | M | |
| 276 | Guy | Celtic | Sensible. | M | |
| 277 | Gwalchmai | Celtic | From Arthurian legend. | M | |
| 278 | Gwawl | Celtic | Mythical son of Clud. | M | |
| 279 | Gwen | Celtic | Mythical son of Gwastad. | M | |
| 280 | Gwern | Celtic | Mythical son of Matholwch. | M | |