| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 401 | Dallin | Irish | Blind. A saint's name. | M | |
| 402 | Dallon | Irish | Variant of Dallin 'blind.'. | M | |
| 403 | Dalon | Irish | Variant of Dallin 'blind.'. | M | |
| 404 | Daly | Irish | Gather together. | M | |
| 405 | Daman | Irish | Tame. | M | |
| 406 | Damon | Irish | Tame. | M | |
| 407 | Daniel | Irish | Attractive. A translation of the Gaelic name Domhnall. | M | |
| 408 | Darby | Irish | Free from envy. A derivitive of Diarmait. Darby and Joan were a devoted elderly married couple originally depicted in a poem or ballad of the 18th century. | M | |
| 409 | Darce | Irish | Diminutive of Darcy: Dark one. | M | |
| 410 | Darcey | Irish | Variant of Darcy: Dark one. | M | |
| 411 | Darcy | Irish | Dark one. | M | |
| 412 | Daric | Irish | Strong; oak-hearted. See also Derek. | M | |
| 413 | Darick | Irish | Strong; oak-hearted. See also Derek. | M | |
| 414 | Darragh | Irish | Black oak; wealthy. | M | |
| 415 | Darrah | Irish | Variant of Darragh: Black oak; wealthy. | M | |
| 416 | Darrick | Irish | Strong; oak-hearted. See also Derek. | M | |
| 417 | Darrie | Irish | Red-haired. | M | |
| 418 | Darroch | Irish | Strong; oak-hearted. See also Derek. | M | |
| 419 | Darrock | Irish | Strong; oak-hearted. See also Derek. | M | |
| 420 | Darry | Irish | Red-haired; wealthy. | M | |