Gabriel

Gaeaf

Gafan

Gafin

Gage

Gar (Gentle, Enclosure, Watchful)

Gareth  

Garfan

Garreth (Gentle, Enclosure, Watchful)

Garth  

Gavan (White hawk)

Gavin (White hawk)

Gawain (Courteous)

Gawen (Courteous)

Geraint (Gentle, or an old man)

Gerallt  

Gerard

Geri

Gerwyn (Fair love)

Gethen (Dark-skinned)

Gethin  

Gideon

Gilbert

Gillanders

Gillean

Gillies

Glain

Glaw (Rain)

Glendower (Valley water)

Glyn  

Glyndwr (Valley water)

Glynn (Valley)

Gobaith

Gofannon (Smith)

Gordan

Gordon

Gorlassar (Above the sky)

Goronwy (Meaning unknown)

Govannon (Smith)

Gracie

Grady

Graeme

Graham

Grahame

Grant

Greg

Griff (Fierce chief, Ruddy)

Griffin (Lord, prince)

Griffith (A powerful lord)

Grigor  

Gruffin (Lord, prince)

Gruffud (Lord, prince)

Gruffudd (Lord, prince)

Gruffudd, Griffith

Gruffydd (Lord, prince)

Grwn (Ridge)

Guorthigern (Overlord)

Gustavo

Guy

Gwalchgwyn (White hawk)

Gwalchmai  

Gwalchmei (May hawk)

Gwallt

Gwallter

Gwas

Gwatcyn

Gwatcyn/Watcyn

Gwelw

Gwen

Gwenno

Gwern

Gwil

Gwil, Gwilym

Gwili

Gwilim  

Gwillym (Will-helmet)

Gwilym

Gwilym, ap Gwilym

Gwledig (Ruler)

Gwyddelig

Gwydderig

Gwyn  

Gwyn, Gwynn and Gwynne

Gwynedd (Happiness)

Gwyneth

Gwynfor  

Gwynn (Fair, holy)

Gwyrdd

Gwythyr  

Hadley

Haf

Halle

Hallie

Halwn (Salt)

Halwyn (Salt)

Hamsa

Hanc

Hanora

Hari

Harlan

Harley

Harri  

Harris, ap Harri

Harvey

Hassan

Hattie

Hayes

Hayleigh

Heber

Hector

Heddwyn  

Hefeydd (Unknown)

Hefin  

Heidn

Heilyn (A steward)

Helwr

Helygen

Hendrics

Henri

Henric

Herb

Herbert

Heseceia

Heulog (Sunny)

Heulyn

Hewney

Hira

Holden

Horace

Houston

Howard

Howell (Eminent)

Hubert

Hudson

Huw  

Huws, Huw

Huxley

Hywel (Eminent)

Iago  

Ianto  

Ianto/Jac

Iarla

Ibrahim

Icer

Idris (Ardent lord)

Idwal (The lord of the wall)

Iefan (Welsh form of John)

Iestin (Welsh form of Justin)

Iestyn  

Iesu

Ieuan  

Ieuan, Ioan

Ifan  

Ifana

Ifans

Ifer

Ifor  

Ignasiws

Ilar  

Illtud (Multitude of people)

Illtyd  

Immanuel, Emanuel

Imran

India

Ines

Ioan  

Ioan, Iwan

Ioan-Pawl

Iolo (A handsome lord)

Iolo, Iori

Iolyn (A handsome lord)

Iona

Iorddonen

Iorwen

Iorwerth

Iorweth (A handsome lord)

Irf

Irfing

Isaac

Ismael

Israel

Iwan  

Iwan Padrig

Iwl

Jadon

Jahseel

Jamir

Jaslyn

Jaylen

Jaylene

Jedidia

Jerome

Jês

Jiwda

Jo

Jocelyn

Joiacim

Jona

Joseff

Joseia

Josh

Joshua

Joss

Keefe

Keelin

Kennedy

Kev

Khalil

Kimberley

Kirby

Knox

Kurt

Kurtis

Kyler

Lachlan

Lafinia

Lamont

Lana

Landen

Landon

Landri

Landyn

Langston

Larri

Lasarws

Layton

Lean

Leana

Lefi

Leland

Lennox

Lesli

Lewis

Lifia

Lincoln

Lleu

Llew  

Llew, Llewelyn

Llewela, Llywela

Llewelyn (Lion-like)

Llifiwr

Lloyd (Grey-haired)

Llundain

Llwyd

Llywellyn (Lion-like)

Llywelyn  

Llywelyn, Llewelyn

Lois

Lorenso

Loyd (Grey-haired)

Luc

Ludovic

Lwcas

Lwcus

Lyn

Mabon  

Mabyn (A son)

Macai

Macs

Macsen  

Maddox (Champion, Good fortune)

Maddy (Champion, Good fortune)

Madlen

Madoc (Champion, Good fortune)

Madog  

Madox (Champion, Good fortune)

Maelgwn

Magnws

Maidoc (Champion, Good fortune)

Mair, Meira

Maircadi

Malachi

Malcwm

Maldwyn  

Malic

Malise

Malori

Manuel/Immanuel

Marc

March (Horse)

Maredudd (Sea day)

Marfin

Marged / Mererid

Mari

Marlen (Sea hill)

Marlin (Sea hill)

Marsel

Marti

Martin

Martyn  

Marwin (Sea hill)

Mason

Math

Mathew

Mathias

Matthews

Maverick

Mawrth  

Maxen (Greatest rival)

Mcensi

Medwyn (A Welsh saint)

Megan/Mared

Meic

Meica

Meical  

Meils

Meistr

Mel

Melfyn

Melinydd

Memffis

Meredudd

Merfyn

Meseia

Mêsi

Meurig

Mihangel

Mihangel, Meical

Mila

Milan

Milltir

Milwr

Moel/Moelwyn

Mohamed

Mohammad

Mohammed

Morgan

Morien

Morris

Mortimer

Moses

Muhammad

Murphy

Myrddin