Gar (Gentle, Enclosure, Watchful)

Gareth (Gentle, Enclosure, Watchful)  

Garreth (Gentle, Enclosure, Watchful)

Garth (Gentle, Enclosure, Watchful)

Gavan (White hawk)

Gavin (White hawk)

Gawain (Courteous)

Gawen (Courteous)

Geraint (Gentle, or an old man)

Gerallt (Rule of the spear)  

Gerwyn (Fair love)

Gethen (Dark-skinned)

Gethin (Dark-skinned)  

Glaw (Rain)

Glendower (Valley water)

Glyn (Valley)  

Glyndwr (Valley water)

Glynn (Valley)

Gofannon (Smith)

Gorlassar (Above the sky)

Goronwy (Meaning unknown)

Govannon (Smith)

Griff (Fierce chief, Ruddy)

Griffin (Lord, prince)

Griffith (A powerful lord)

Grigor (Watchful, vigilant)  

Gruffin (Lord, prince)

Gruffud (Lord, prince)

Gruffudd (Lord, prince)

Gruffydd (Lord, prince)

Grwn (Ridge)

Guorthigern (Overlord)

Gwalchgwyn (White hawk)

Gwalchmai (May hawk)

Gwalchmei (May hawk)

Gwilim (Will-helmet)  

Gwillym (Will-helmet)

Gwledig (Ruler)

Gwyn (White, fair)  

Gwynedd (Happiness)

Gwynfor (From the fair place)  

Gwynn (Fair, holy)

Gwythyr (Conqueror)

Halwn (Salt)

Halwyn (Salt)

Harri (Home ruler)  

Heddwyn (Blessed peace)  

Hefeydd (Unknown)

Hefin (Summer)

Heilyn (A steward)

Heulog (Sunny)

Howell (Eminent)

Huw (Heart and mind)  

Hywel (Eminent)

Iago (Supplanter)  

Ianto (God is gracious)  

Idris (Ardent lord)

Idwal (The lord of the wall)

Iefan (Welsh form of John)

Iestin (Welsh form of Justin)  

Iestyn (Welsh form of Justin)  

Ieuan (Welsh form of John)  

Ifan (Welsh form of John)  

Ifor (Ifor)  

Ilar (Cheerful)  

Illtud (Multitude of people)

Illtyd (Multitude of people)  

Ioan (Welsh form of John)  

Iolo (A handsome lord)

Iolyn (A handsome lord)

Iorweth (A handsome lord)

Iwan (Welsh form of John)  

Llew (Lion-like)  

Llewelyn (Lion-like)

Lloyd (Grey-haired)

Llywellyn (Lion-like)

Llywelyn (Lion-like)  

Loyd (Grey-haired)

Mabon (A son)  

Mabyn (A son)

Macsen (The greatest rival)  

Maddox (Champion, Good fortune)

Maddy (Champion, Good fortune)

Madoc (Champion, Good fortune)

Madog (Champion, Good fortune)  

Madox (Champion, Good fortune)

Maidoc (Champion, Good fortune)

Maldwyn (Brave friend)  

March (Horse)

Maredudd (Sea day)

Marlen (Sea hill)

Marlin (Sea hill)

Martyn (Warlike)  

Marwin (Sea hill)

Mawrth (Of the sea)  

Maxen (Greatest rival)

Medwyn (A Welsh saint)

Meical (Who is like God)