- GLAN MENAI - see JONES, GRIFFITH
- GLAN PHERATH - see HUGHES, THOMAS
- GLAN RHYDDALLT - see LLOYD, ISAAC SAMUEL
- GLANBERACH - see MORGAN, JOHN JENKYN
- GLANCERI - see CROWTHER, JOHN NEWTON
- GLANFFRWD - see THOMAS, WILLIAM
- GLANLLAFAR - see EDWARDS, WILLIAM ROBERT
- GLANMOR - see WILLIAMS, JOHN
- GLANUSK, Barons - see BAILEY
- GLANYSTWYTH - see HUGHES, JOHN
- GLASCOTT, CRADOCK (1743 - 1831), Evangelical cleric
- GLASGOED - see HUGHES, OWEN
- GLASLYN - see OWEN, RICHARD JONES
- GLASYNYS - see JONES, OWEN WYNNE
- GLENN, THOMAS ALLEN (1864 - 1948), soldier, historian, genealogist, and archaeologist
- GLUN BREN, Y - see DAVIES, RHYS
- GLYN family Glynllifon,
- GLYN, GEOFFREY (d. 1557), founder of Friars School, Bangor - see GLYN, WILLIAM
- GLYN, JOHN, dean of Bangor - see GLYN, WILLIAM
- GLYN, WILLIAM (1504 - 1558), bishop
- GLYNLLIFON, WILLIAM Glynllifon (d. 1594) - see GLYN
- GLYNNE family
- GLYNNE, Glynllifon - see GLYN
- GLYNNE, MARY DILYS (1895 - 1991), plant pathologist
- GLYNNE, WALTER - see WALTERS, THOMAS GLYN
- GOCH, MATHAU - see GOUGH, MATHEW
- GOCH, MATHEW - see GOUGH, MATHEW
- GODWIN, FRANCIS (1562 - 1633), bishop and antiquary
- GODWIN, JUDITH (d. 1746), one of Howel Harris's correspondents
- GOGRYNWR - see JONES, THOMAS
- GOHEBYDD, Y - see GRIFFITH, JOHN
- GOLDEN FARMER - see DAVIS, WILLIAM
- GOLDSWAIN, BRYNLEY VERNON (1922 - 1983), rugby league player
- GOLEUFRYN - see JONES, WILLIAM RICHARD
- GOLYDDAN - see PRYSE, ROBERT JOHN
- GOMER - see HARRIS, JOSEPH
- GOMERIAN - see DAVIES, ROBERT HUMPHREY
- GOMERYDD - see EVANS, SAMUEL
- GOODEN, JAMES (1670 - 1730), Jesuit
- GOODMAN, GABRIEL (1528 - 1601), dean of Westminster and founder of Christ's Hospital, Ruthin
- GOODMAN, GODFREY (1583 - 1656), bishop of Gloucester
- GOODWIN, GERAINT (1903 - 1941), author
- GOODWIN, JOHN (1681 - 1763) North Wales, Quaker minister
- GORE, HUGH (1613 - 1691), bishop, founder of Swansea grammar school
- GORE, WILLIAM GEORGE ARTHUR ORMSBY - see ORMSBY-GORE, WILLIAM GEORGE ARTHUR
- GORFYNIAWC O ARFON - see WILLIAMS, JOHN
- GORONWY DDU - see MATHIAS, JAMES GORONWY
- GORONWY DDU O FON - see OWEN, GORONWY
- GORONWY GYRIOG (fl. c. 1310-1360), poet
- GORONWY-ROBERTS, Baron - see ROBERTS, GORONWY OWEN