| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 321 | Kent | Celtic | Chief. | M | |
| 322 | Kentigem | Celtic | Chief. | M | |
| 323 | Kentigern | Celtic | Chief lord. Name of the first bishop of Glasgow. | M | |
| 324 | Kermit | Celtic | Son of Diarmaid. | M | |
| 325 | Kermode | Celtic | Son of Diarmaid. | M | |
| 326 | Kerry | Celtic | Dark. | M | |
| 327 | Kerwin | Celtic | Dark skinned. | M | |
| 328 | Kerwyn | Celtic | Dark skinned. | M | |
| 329 | Kevan | Celtic | Gentle. | M | |
| 330 | Kevin | Celtic | Gentle. | M | |
| 331 | Kevyn | Celtic | Gentle. | M | |
| 332 | Kieran | Celtic | Dark skinned. | M | |
| 333 | Kilian | Celtic | Blind. | M | |
| 334 | Killian | Celtic | Blind. | M | |
| 335 | Kirwin | Celtic | Dark skinned. | M | |
| 336 | Kirwyn | Celtic | Dark skinned. | M | |
| 337 | Kunsgnos | Celtic | Wise. | M | |
| 338 | Kynthelig | Celtic | Guide. | M | |
| 339 | Lairgnen | Celtic | Of Connaught. | M | |
| 340 | Lee | Celtic | Healer. | M | |