| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 321 | Darrick | Gaelic | Strong; oak-hearted. See also Derek. | M | |
| 322 | Darrin | Gaelic | Variant of Darren: Great. | M | |
| 323 | Darroch | Gaelic | Strong; oak-hearted. See also Derek. | M | |
| 324 | Darrock | Gaelic | Strong; oak-hearted. See also Derek. | M | |
| 325 | Darron | Gaelic | Variant of Darren: Great. | M | |
| 326 | Darryn | Gaelic | Variant of Darren: Great. | M | |
| 327 | DAry | Gaelic | Dark. | M | |
| 328 | Daryn | Gaelic | Great. | M | |
| 329 | Dearan | Gaelic | Great. | M | |
| 330 | Deardriu | Gaelic | Raging. | F | |
| 331 | Deasach | Gaelic | Southerner. | M | |
| 332 | Deasmumhan | Gaelic | Man from south Munster. | M | |
| 333 | Deegan | Gaelic | Black-haired. | M | |
| 334 | Deidra | Gaelic | Raging. | F | |
| 335 | Deirdre | Gaelic | Raging. | F | |
| 336 | Delano | Gaelic | Healthy black man. | M | |
| 337 | Dempsey | Gaelic | Proud. | M | |
| 338 | Deorsa | Gaelic | Farmer. | M | |
| 339 | Dermod | Gaelic | Free man. | M | |
| 340 | Dermot | Gaelic | Free man. | M | |