- LEWIS MEIRCHION - see LEWIS ap EDWARD
- LEWIS MENAI (fl. second half of the 16th century), poet
- LEWIS MON (fl. c. 1480-1527) Llifon, Anglesey, a poet
- LEWIS of CAERLEON (fl. 1491), mathematician, theologian, doctor of medicine, and teacher at Oxford
- LEWIS POWYS (fl. c. 1530), poet
- LEWIS TREFNANT (fl. 1550-1580), poet
- LEWIS TYMBL - see LEWIS, DAVID JOHN
- LEWIS, Sir ALFRED (EDWARD) (1868 - 1940), banker
- LEWIS, ALUN (1915 - 1944), poet
- LEWIS, BENJAMIN (d. 1749), hymnist
- LEWIS, BENJAMIN WALDO (1877 - 1953), Baptist minister
- LEWIS, CHARLES PRYTHERCH (1853 - 1923), Welsh Rugby footballer and Oxford 'triple Blue'
- LEWIS, DAVID (Baker, Charles; 1617 - 1679), Jesuit martyr
- LEWIS, DAVID (1828 - 1908), musician
- LEWIS, DAVID (1848 - 1897), lawyer
- LEWIS, DAVID (1760 - 1850), cleric
- LEWIS, DAVID (1683? - 1760), poet
- LEWIS, DAVID (1520? - 1584), first principal of Jesus College, Oxford
- LEWIS, DAVID (Ap Ceredigion; 1870 - 1948), cleric, poet, and hymn-writer
- LEWIS, DAVID (1778 - 1859), schoolmaster - see LEWIS, EVAN
- LEWIS, DAVID (1814 - 1895), cleric - see LEWIS, EVAN
- LEWIS, DAVID - see LEWIS
- LEWIS, DAVID EMRYS (1887 - 1954), poet and journalist
- LEWIS, DAVID JOHN (1893 - 1982), architect and Lord Mayor of Liverpool
- LEWIS, DAVID JOHN (Lewis Tymbl; 1879 - 1947), Congl. minister, popular preacher and lecturer
- LEWIS, DAVID MORGAN (1851 - 1937), Congregational minister, afterwards professor of physics
- LEWIS, DAVID VIVIAN PENROSE (1st Baron Brecon), (1905 - 1976), politician
- LEWIS, DAVID WATTS (c.1830 - 1896), Presbyterian minister - see LEWIS, GRUFFYDD THOMAS
- LEWIS, DAVID WILLIAM (1845 - 1920), musician
- LEWIS, DAVID WYRE (1872 - 1966), minister and administrator (B)
- LEWIS, EDWARD - see LEWIS
- LEWIS, EDWARD ARTHUR (1880 - 1942), historian
- LEWIS, ELLIS (fl. 1640-1661), translator
- LEWIS, ELLIS (1677 - 1764), Quaker minister - see LEWIS
- LEWIS, EMLYN EVANS (1905 - 1969), plastic surgeon
- LEWIS, ERASMUS (1670 - 1754), writer of 'news-letters' and holder of posts under the Government
- LEWIS, EVAN (1818 - 1901), dean of Bangor
- LEWIS, EVAN (1788? - 1864), Dissenting minister
- LEWIS, FRANCIS (1713 - 1802), one of the signatories of the American Declaration of Independence
- LEWIS, GEORGE (1763 - 1822), theologian and Independent minister
- LEWIS, GEORGE (Eiddil Llwyn Celyn; 1826? - 1858), poet and shoemaker
- LEWIS, GEORGE (c. 1640? - 1709?), cleric and author
- LEWIS, Sir GEORGE CORNEWALL (1806 - 1863), statesman
- LEWIS, GRUFFYDD THOMAS (1873 - 1964), schoolmaster and a leading layman in the Presbyterian Church of Wales
- LEWIS, Sir HENRY (1847 - 1923) North Wales, Calvinistic Methodist elder
- LEWIS, HENRY (1889 - 1968), Welsh and Celtic scholar, university professor
- LEWIS, HENRY GETHIN (1872 - 1945), merchant and financier
- LEWIS, HOWELL ELVET (ELFED; 1860 - 1953), Independent minister, hymn-writer, poet
- LEWIS, HUBERT (1825 - 1884), jurist
- LEWIS, HUGH (1562 - 1634), cleric, author, poet