- 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
- HOOSON, ISAAC DANIEL (1880 - 1948), solicitor and poet
- HOOSON, JOHN (1883 - 1969), teacher, scholar
- HOOSON, TOM ELLIS (1933 - 1985), Conservative politician
- HOPCYN - see JAMES, LEMUEL JOHN HOPKIN
- HOPCYN ap TOMAS (c. 1330 - 1403), gentleman
- HOPCYN, WILIAM (1700 - 1741), poet
- HOPE, WILLIAM (fl. 1765), itinerant bookseller and poet
- HOPKIN, LEWIS (c. 1708 - 1771), poet
- HOPKIN-JAMES, LEMUEL JOHN HOPKIN - see JAMES, LEMUEL JOHN HOPKIN
- HOPKINS, BENJAMIN THOMAS (1897 - 1981), farmer and poet
- HOPKINS, EVAN ([1801]? - 1888), geologist
- HOPKINS, GERARD MANLEY (1844 - 1889), poet and priest
- HOPKINS, WILLIAM (1706 - 1786), cleric and author
- HORSFALL TURNER, ERNEST RICHMOND (1870 - 1936), schoolmaster and local historian
- HOWARD DE WALDEN, 8th Baron - see SCOTT-ELLIS, THOMAS EVELYN
- HOWARD, JAMES HENRY (1876 - 1947), preacher, author and socialist
- HOWE, ELIZABETH ANNE (1959 - 2019), ecologist
- HOWEL ap GRUFFYDD - see HYWEL ap GRUFFYDD
- HOWEL, HARRI (fl. 1637-1671), bard
- HOWELL, DAVID (Llawdden; 1831 - 1903), dean
- HOWELL, DAVID (1797 - 1873), Calvinistic Methodist minister
- HOWELL, GWILYM (1705 - 1775), almanac-maker and poet
- HOWELL, JAMES (1594? - 1666), author
- HOWELL, JENKIN (1836 - 1902), printer, writer, musician
- HOWELL, JOHN (Ioan ab Hywel, Ioan Glandyfroedd; 1774 - 1830), weaver, schoolmaster, poet, editor, and musician
- HOWELL, JOHN (d. 1880), farmer - see HOWELL, DAVID
- HOWELL, JOHN HENRY (1869 - 1944), pioneer of technical education in New Zealand
- HOWELL, LLEWELYN DAVID (1812 - 1864), Congregational minister, author, and eisteddfodwr
- HOWELL, THOMAS (d. 1540?), philanthropist
- HOWELL, THOMAS (1588 - 1646), bishop
- HOWELL, THOMAS FRANCIS (1864 - 1953), businessman and barrister
- HOWELL, WILLIAM (1740 - 1822), Arian minister and Academy tutor
- HOWELL, WILLIAM - see HOWELL, GWILYM
- HOWELLS, ELISEUS (1893 - 1969), minister (Presb.), and author
- HOWELLS, GEORGE (1871 - 1955), principal of Serampore College, India
- HOWELLS, GERAINT WYN (Baron Geraint), (1925 - 2004), farmer and politician
- HOWELLS, HOWELL (1750 - 1842), Methodist cleric
- HOWELLS, MORGAN (1794 - 1852), Calvinistic Methodist minister
- HOWELLS, REES (1879 - 1950), missionary and founder of the Bible College, Swansea
- HOWELLS, THOMAS (Hywel Cynon; 1839 - 1905), collier, printer, poet, preacher, and musician
- HOWELLS, WILLIAM (1818 - 1888), Calvinistic Methodist minister and second principal of Trevecka College
- HOWELS, WILLIAM (1778 - 1832), Evangelical cleric
- HOYLE, WILLIAM EVANS (1855 - 1926), first director of the National Museum of Wales
- HUDDLESTON, WILLIAM REGINALD HERBERT - see HERBERT, WILLIAM REGINALD
- HUDSON-WILLIAMS, THOMAS (1873 - 1961), scholar and translator