| Leprechaun |
Luprecan |
| Levarcam |
Levarcham |
| Lewy |
Lugaid |
| Llenlleawc |
Llwch Llawwyanawc - Lleminawc - Llenllawc |
| Llevelys |
Llefelys |
| Lorica |
Luirech |
| Lugaid |
Lewy |
| Lugh |
Lug - Lugh of the Long Arm |
| Luned |
Lunet - Linet |
| Mac Cuill |
Mac Quill |
| Mac Kerval |
Dermot |
| Maeve |
Medb |
| Manawydan |
Manawyddan |
| Maponos |
Maponus |
| Mara |
Mera |
| Maxen Wledig |
Macsen Wledig - Maximus |
| May Eve |
May Day |
| Melvas |
Meleagaunce - Meleagraunce |
| Merrows |
Murdhuacha - Mermaids |
| Midir |
Mider - Midhir - Midar |
| Moddey Dhoo |
Mauthe Doog |
| Morgan |
Morgana - Morgan Le Fay |
| Munsalvsche |
Montsalvat |
| Myrddin |
Merlin |
| Naoisi |
NoĦsiu |
| Neman |
Neamhan - Nemainn |
| Nicht Nought Nothing |
Nicht Nocht Naethin |
| Noggle |
Nuggle - Nygel |
| Odin |
Woden |
| Oenghus |
Oengus Mac Og - Angus |
| Ogham |
Ogamic Oimelc - Imbolc |
| Oscar |
Osgar |
| Osfrid |
Osfrith Osthryd - Osthryth |
| Pach |
Patch |
| Padern |
Paternus |
| Partholon |
Partholan |
| Pechs |
Pehts - Picts |
| Pellam |
Pelles |
| Pixies |
Pigsies - Piskies |
| Rhitta |
Ricca - Rith |
| Samhain |
Samain - Samuin |
