| Hywel | Welsh | Derived from hywel (eminent, promin.. |  |  |
| Idris | Welsh | Compound name composed of the eleme.. |  | |
| Iefan | Welsh | Welsh cognate of John (God is graci.. | | |
| Iestyn | Welsh | Welsh form of Justin (lawful, right.. | | |
| Ieuan | Welsh | Original Welsh form of John (God is.. | | |
| Ifor | Welsh | Ancient yet still common name of un.. | | |
| Ilar | Welsh | Welsh form of Hilary (cheerful). Se.. | | |
| Illtud | Welsh | Compound name composed of the eleme.. | | |
| Iolo | Welsh | This name means "the Lord is worthy.. | | |
| Iorwerth | Welsh | Popular compound name composed of i.. | | |
| Islwyn | Welsh | Transferred use of a Welsh place-na.. | | |
| Isolde | Welsh | Of debated origin and meaning, Isol.. | | |
| Ithel | Welsh | A name that signifies "generous lor.. | | |
| Ivor | Welsh | Derived from the Scandinavian Ivar .. | | |
| Jane | Welsh | A borrowing from the English, Jane .. |  | |
| Janet | Welsh | A borrowing from the English, Janet.. |  | |
| Jenkin | Welsh | Transferred use of the surname orig.. | | |
| Jennifer | Welsh | An alternate form of Guinevere, whi.. | | |
| John | Welsh | A borrowing from the English, John .. | | |
| Kai | Welsh | Meaning "keeper of the keys." | | |
| Kane | Welsh | This name means "beautiful."
| | |
| Kendall | Welsh | Transferred use of the surname deri.. | | |
| Kendall | Welsh | Transferred use of the surname deri.. | | |
| Kent | Welsh | A name that means "white" or "brigh.. | | |
| Lewis | Welsh | A borrowing from the English, Lewis.. | | |
| Lleu | Welsh | Derived from the element lieu (brig.. | | |
| Lleulu | Welsh | Welsh form of Lucia, a feminine for.. | | |
| Llew | Welsh | Derived from Hew (lion). The name i.. | | |
| Llewellyn | Welsh | Meaning "lion-like." | | |
| Llewelyn | Welsh | Ancient name of uncertain etymology.. | | |
| Lloyd | Welsh | Anglicized form of the Welsh Llwyd .. | | |
| Llwyd | Welsh | A direct derivation of llwyd (gray).. | | |
| Lowri | Welsh | This name has the meaning "crown of.. | | |
| Luned | Welsh | Popular name derived from the Welsh.. | | |
| Mabon | Welsh | From the Old Celtic element mah (so.. | | |
