- HENRY, THOMAS (1734 - 1816), apothecary, physician, and chemist
- HENRY, WILLIAM (1774 - 1836), chemist - see HENRY, THOMAS
- HENRY, WILLIAM CHARLES (1804 - 1892), chemist - see HENRY, THOMAS
- HERBERT family Montgomery, Parke, Blackhall, Dolguog, Cherbury, Aston,
- HERBERT family (earls of POWIS),
- HERBERT family
- HERBERT of CHERBURY, 1st Baron - see HERBERT, EDWARD
- HERBERT, DAVID (1762 - 1835), Evangelical cleric
- HERBERT, EDWARD (1583 - 1648), 1st baron Herbert of Cherbury
- HERBERT, GEORGE (1593 - 1633), cleric and poet
- HERBERT, HENRY (1617 - 1656), Parliamentary soldier and statesman
- HERBERT, Sir JOHN (1550 - 1617), civil lawyer, diplomat and secretary of state
- HERBERT, WILLIAM (1460 - 1491), earl of Pembroke, later earl of Huntingdon
- HERBERT, WILLIAM (earl of Pembroke), (d. 1469), soldier and statesman
- HERBERT, WILLIAM (1796 - 1893), vicar - see HERBERT, DAVID
- HERBERT, Sir WILLIAM (d. 1593), Irish planter and Welsh educational pioneer
- HERBERT, WILLIAM REGINALD (1841 - 1929), sportsman, huntsman and rider of racehorses
- HEREFORD, Viscounts - see DEVEREUX
- HERRING, JOHN (1789 - 1832), Baptist minister
- HEYCOCK of TAIBACH, Lord - see HEYCOCK, LLEWELLYN
- HEYCOCK, GEORGE REES - see REES, GEORGE
- HEYCOCK, LLEWELLYN (LORD HEYCOCK OF TAIBACH), (1905 - 1990), prominent leader in local government in Glamorganshire
- HEYLIN, PETER (1599 - 1599), publisher of Welsh books - see HEYLIN, ROWLAND
- HEYLIN, ROWLAND (1562? - 1631), publisher of Welsh books
- HEYLYN, ROWLAND - see HEYLIN, ROWLAND
- HICKS, HENRY (1837 - 1899), physician and geologist
- HIGGS, DANIEL (d. 1691), Puritan minister
- HILEY, FRANCIS (1781 - 1860), Baptist minister
- HILL family, Plymouth iron-works, Merthyr Tydfil
- HILLS-JOHNES, Sir JAMES (1833 - 1919), general
- HIMBURY, DAVID MERVYN (1922 - 2008), minister (Bapt) and college principal
- HINDE, CHARLES THOMAS EDWARD (1820 - 1870), major general
- HININ FARDD (1360? - 1420), writer of prophecies
- HOARE, Sir RICHARD COLT (1758 - 1838), 2nd baronet, historian and antiquary
- HOBLEY, WILLIAM (1858 - 1933), Calvinistic Methodist minister, and author
- HODDINOTT, ALUN (1929 - 2008), composer and teacher
- HODGES, JEHOIADA (1877? - 1930), Wales and Newport Rugby forward
- HODGES, JOHN (1700? - 1777), cleric
- HOGGAN, FRANCES ELIZABETH (1843 - 1927), physician and social reformer
- HOGGAN, FRANCES ELIZABETH (1843 - 1927)
- HOLBACHE, DAVID (fl. 1377-1423), lawyer, founder of Oswestry Grammar School
- HOLBECHE, DAVID - see HOLBACHE, DAVID
- HOLLAND family
- HOLLAND family Berw,
- HOLLAND, HUGH (1569 - 1633), poet and traveller
- HOLLAND, ROBERT (1556/7 - 1622?), cleric, author, and translator
- HOLLAND, SAMUEL (1803 - 1892), a pioneer of the North Wales slate industry and chief promoter of the establishment of Dr. Williams's school for girls at Dolgelley
- HOLLAND, WILLIAM (1711 - 1761), early Methodist and Moravian
- HOMFRAY family, iron-masters Penydarren
- HOOSON, HUGH EMLYN (1925 - 2012), Liberal politician and public figure