- GABE, RHYS THOMAS (1880 - 1967), rugby player
- GALFRIDUS ARTUR - see GEOFFREY of MONMOUTH
- GALFRIDUS MONEMUTENSIS - see GEOFFREY of MONMOUTH
- GALLENSIS, JOHANNES - see WALLENSIS, JOHANNES
- GALLIE, MENNA PATRICIA (1919 - 1990), writer
- GAMAGE family Coety, Coity,
- GAMBOLD family
- GAMES, - see DAFYDD GAM
- GAPE, REES THOMAS - see GABE, RHYS THOMAS
- GARRO JONES, GEORGE MORGAN - see TREFGARNE, GEORGE MORGAN
- GAUFRIDUS ARTUR - see GEOFFREY of MONMOUTH
- GAUFRIDUS MONEMUTENSIS - see GEOFFREY of MONMOUTH
- GEE, HOWEL (d. 1903), journalist - see GEE, THOMAS
- GEE, THOMAS (1815 - 1898), Calvinistic Methodist minister, journalist, and politician
- GEOFFREY (1090? - 1155), bishop of St Asaph and chronicler
- GEORGE, - see LLOYD GEORGE
- GEORGE, DAVID LLOYD - see LLOYD GEORGE, DAVID
- GEORGE, THOMAS (fl. 1829-1840), miniature painter
- GEORGE, THOMAS NEVILLE (1904 - 1980), Professor of Geology
- GEORGE, WILLIAM (1865 - 1967), solicitor and public figure
- GERAINT, Baron - see HOWELLS, GERAINT WYN
- GERALD OF WALES - see GIRALDUS CAMBRENSIS
- GERALLT GYMRO - see GIRALDUS CAMBRENSIS
- GERVASE - see IORWERTH
- GETHIN - see JONES, OWEN GETHIN
- GETHIN DULAIS - see DAVIES, GETHIN
- GETHIN, MAURICE, steward of Aberconwy abbey - see WYNNE
- GIBBINS, FREDERICK WILLIAM (1861 - 1937), Quaker industrialist
- GIBBON, BENJAMIN PHELPS (1802 - 1851), line-engraver
- GIBBON, JAMES MORGAN (1855 - 1932), Independent minister
- GIBBON, LEVI (1807? - 1870), ballad-writer and singer
- GIBBS, REGINALD ARTHUR (1872 - 1938), shipowner (one of four brothers, all prominent in Cardiff shipping circles), and Rugby footballer
- GIBBS, SION (fl. 1643), poet
- GIBSON, BENJAMIN (1811 - 1851), antiquary - see GIBSON, JOHN
- GIBSON, JOHN (1790 - 1866), sculptor
- GIBSON, Sir JOHN (1841 - 1915), journalist
- GIBSON-WATT, JAMES DAVID (BARON GIBSON-WATT), (1918 - 2002), Member of Parliament and public figure
- GIFFORD, ISABELLA (c. 1825 - 1891), botanist and algologist
- GILBERTSON, LEWIS (1814 - 1896), cleric, vice-principal of Jesus College, Oxford
- GILDAS (fl. 6th cent), monk
- GILLHAM, MARY ELEANOR (1921 - 2013), naturalist and educator
- GIRALDUS - see GRIFFITH, OWEN
- GIRALDUS - see ROWLANDS, JOHN
- GIRALDUS CAMBRENSIS (1146? - 1223), archdeacon of Brecon and mediaeval Latin writer
- GITTINS, CHARLES EDWARD (1908 - 1970), educationalist
- GITTINS, EDWARD (Iorwerth Pentyrch; 1843 - 1884), local historian
- GIVVONS, ALEXANDER (1913 - 2002), rugby player
- GLAN ALAW - see JONES, RICHARD
- GLAN ALUN - see JONES, THOMAS
- GLAN BARLWYD - see JONES, JOHN WILLIAM