- DAVIES, WILLIAM CADWALADR (1849 - 1905), educationist
- DAVIES, WILLIAM DANIEL (1838 - 1900), lecturer and author
- DAVIES, WILLIAM DAVID (1911 - 2001), Biblical scholar
- DAVIES, WILLIAM DAVID [P.] (1897 - 1969), minister (Presb.), college tutor and author
- DAVIES, WILLIAM EDWARDS (1851 - 1927), Cymmrodor and eisteddfodwr
- DAVIES, WILLIAM HENRY (1871 - 1940), poet and author
- DAVIES, WILLIAM HUBERT (1893 - 1965), musician
- DAVIES, WILLIAM JENKIN (1858 - 1919), Unitarian minister, man of letters, and musician
- DAVIES, WILLIAM LEWIS (1896 - 1941), specialist in analytical dairy chemistry
- DAVIES, WILLIAM THOMAS (PENNAR) (1911 - 1996), novelist, poet, theologian and scholar
- DAVIES, WINDSOR (1930 - 2019), actor
- DAVIES, ZACCHEUS (fl. 1737-1770), writer of religious carols (halsingod)
- DAVIES-COOKE family Gwysaney, Llannerch, Gwysaney,
- DAVIS family, coalowners
- DAVIS, DAVID (Dafis Castellhywel; 1745 - 1827), Arian minister, poet, and schoolmaster
- DAVIS, DAVID (1778 - 1846), Unitarian minister - see DAVIS, DAVID
- DAVIS, DAVID DANIEL (1777 - 1841), physician
- DAVIS, ELIZABETH (1789 - 1860), nurse and traveller
- DAVIS, RICHARD (1658 - 1714), Independent minister
- DAVIS, THOMAS - see DAVIES, THOMAS
- DAVIS, TIMOTHY (1709 - 1771), Independent minister - see DAVIS, DAVID
- DAVIS, TIMOTHY (1779 - 1860), Unitarian minister - see DAVIS, DAVID
- DAVIS, WILLIAM (Golden Farmer; 1627 - 1690), highwayman
- DAVYES, THOMAS - see DAVIES, THOMAS
- DAVYS, MATTHEW - see DAVIES, MATTHEW
- DAWE, CHARLES (DAVIES) (1886 - 1958), choral conductor
- DAWKINS, MORGAN GAMAGE (1864 - 1939), Congregational minister, poet, and hymnist
- DAWKINS, Sir WILLIAM BOYD (1837 - 1929), geologist and antiquary
- DE AVENE, LLEISION (d. 1328) - see MORGAN FYCHAN
- DE BARRI, GERALD - see GIRALDUS CAMBRENSIS
- DE BARRI, GIRALDUS - see GIRALDUS CAMBRENSIS
- DE FREITAS BRAZAO, IRIS (1896 - 1989), lawyer
- DE LA POLE, OWAIN (d. 1293) - see GRUFFYDD ap GWENWYNWYN
- DE LA POLE, OWEN (d. 1293) - see GRUFFYDD ap GWENWYNWYN
- DE LACY, - see LACY
- de LACY, , constables of Chester - see LACY, de
- DE LLOYD, DAVID JOHN (1883 - 1948), musician
- DE SAEDELEER, ELISABETH (1902 - 1972), textile artist
- DEAKIN, ARTHUR (1890 - 1955), trade union leader
- DEBORAH MALDWYN - see HUGHES, JANE
- DEE, JOHN (1527 - 1608), mathematician and astronomer
- DEFYNNOG - see JAMES, DAVID
- DEINIOL (d. 584), saint, founder of Bangor and first bishop in Gwynedd
- DEIO ap IEUAN BWL (fl. c. 1530), poet
- DEIO ap IEUAN DU (fl. 1460-1480), poet
- DEIO LLIWIEL (LLYWEL?) (fl. beginning of 16th century?), poet
- DEIO LLYWEL - see DEIO LLIWIEL
- DEIO YSGOLHAIG - see LLWYD, Sir DAFYDD
- DENNIS, HENRY (1825 - 1906), mining engineer, colliery owner, etc.
- DERFEL, R. J. - see DERFEL, ROBERT JONES