| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 281 | Dewey | Welsh | The Lord's. | M | |
| 282 | Dewi | Welsh | Variant of David: Beloved or friend, from the Hebrew. Sixth century St David (or Dewi) was patron saint of Wales. | M | |
| 283 | Dicra | Welsh | Slow. | F | |
| 284 | Dierdre | Welsh | Dark. | F | |
| 285 | Difyr | Welsh | Amusing. | F | |
| 286 | Digon | Welsh | Legendary son of Alar. | M | |
| 287 | Dilan | Welsh | Born near the sea. | M | |
| 288 | Dillan | Welsh | Variant of Dylan: Ocean's son. | M | |
| 289 | Dillie | Welsh | Born near the sea. | M | |
| 290 | Dillon | Welsh | Born near the sea. | M | |
| 291 | Dillus | Welsh | Legendary son of Eurei. | M | |
| 292 | Dillwyn | Welsh | Variant of Dilwyn: Blessed truth. | M | |
| 293 | Dilwyn | Welsh | Blessed truth. | M | |
| 294 | Dilys | Welsh | Genuine, perfect, true. This name was first used in Wales in the mid-19th century. | F | |
| 295 | Dirrnyg | Welsh | Legendary son of Caw. | M | |
| 296 | Donne | Welsh | Used in honor of 17th century poet John Donne. | M | |
| 297 | Dover | Welsh | Water. A British seaport on the English channel. | M | |
| 298 | Drem | Welsh | Sight. | M | |
| 299 | Dremidydd | Welsh | Legendary father of Drem. | M | |
| 300 | Drew | Welsh | Wise. | M | |