| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 641 | Fionnbharr | Irish | Variant of Finbar: Blond-haired; handsome. | M | |
| 642 | Fitzgerald | Irish | Surname. | M | |
| 643 | Fitzpatrick | Irish | Statesman's son. | M | |
| 644 | Fitzwilliam | Irish | Soldier's son. | M | |
| 645 | FIynn | Irish | Ruddy. | M | |
| 646 | Flaine | Irish | Variant of Flannery: Red-haired. | M | |
| 647 | Flainn | Irish | Ruddy. | M | |
| 648 | Flanagan | Irish | Ruddy. | M | |
| 649 | Flann | Irish | Ruddy. | M | |
| 650 | Flannagain | Irish | Ruddy. | M | |
| 651 | Flannagan | Irish | Surname. | M | |
| 652 | Flannan | Irish | Variant of Flannery: Red-haired. | M | |
| 653 | Flannery | Irish | Red-haired. | M | |
| 654 | Flin | Irish | Variant of Flynn: Son of a red-haired man. | M | |
| 655 | Flinn | Irish | Son of a red-haired man. | M | |
| 656 | Floinn | Irish | Ruddy. | M | |
| 657 | Flurry | Irish | In bloom. | M | |
| 658 | Flyn | Irish | Son of a red-haired man. | M | |
| 659 | Flynn | Irish | Son of a red-haired man. Surname. | M | |
| 660 | Fogartaigh | Irish | Exiled. | M | |