- BACON family, iron-masters and colliery proprietors
- BADDY, THOMAS (d. 1729), Independent minister and author
- BAILEY family Nant-y-glo,
- BAILEY family Glanusk Park,
- BAKER, CHARLES (1617 - 1679), Jesuit martyr - see LEWIS, DAVID
- BAKER, DAVID (1575 - 1641), Benedictine scholar and mystic
- BAKER, ELIZABETH (c. 1720 - 1789), diarist
- BAKER, WILLIAM STANLEY (1928 - 1976), actor and producer
- BAKER, VEN. AUGUSTINE - see BAKER, DAVID
- BALLINGER, Sir JOHN (1860 - 1933), first librarian of the National Library of Wales
- BANCROFT, WILLIAM JOHN (1871 - 1959), rugby player and cricketer
- BANKES, Sir JOHN ELDON (1854 - 1946), judge
- BARD OF SNOWDON - see LLWYD, RICHARD
- BARDD ALAW - see PARRY, JOHN
- BARDD BACH, Y - see RHYS FARDD
- BARDD BRYNCROES - see PRITCHARD, EVAN
- BARDD BYDDAR, Y - see HOPE, WILLIAM
- BARDD CLOFF, Y - see JONES, THOMAS
- BARDD COCH - see HOWELL, DAVID
- BARDD COCH - see ELIAS, THOMAS
- BARDD COCH LLANGRALLO - see HOWELL, DAVID
- BARDD COCOS - see EVANS, JOHN
- BARDD CRWST - see JONES, ABEL
- BARDD CWSG - see RHYS FARDD
- BARDD DU ERYRI - see WILLIAMS, ABRAHAM
- BARDD DU MÔN - see WILLIAMSON, ROBERT
- BARDD EINION - see MORRIS, DAVID
- BARDD HOREB - see THOMAS, EVAN
- BARDD MÔN - see JONES, EDWARD
- BARDD NANTGLYN - see DAVIES, ROBERT
- BARDD TREFLYS - see ROBERTS, RICHARD
- BARDD Y BRENIN - see JONES, EDWARD
- BARDD Y GWAGEDD - see WILLIAMS, RICHARD
- BARDD Y NANT - see JONES, WILLIAM
- BARDD, Y - see MORGAN, WILLIAM
- BARHAM family Trecŵn,
- BARHAM, DIANA (1763 - 1823), peeress in her own right, 1813, benefactress of the evangelical movement
- BARKER family, artists
- BARKER, THOMAS WILLIAM (1861 - 1912), registrar of the diocese of S. Davids
- BARLOW, JOHN, dean of Worcester - see BARLOW, WILLIAM
- BARLOW, ROGER Slebech Pembs - see BARLOW, WILLIAM
- BARLOW, THOMAS, rector Catfield - see BARLOW, WILLIAM
- BARLOW, WILLIAM (1499? - 1568), bishop
- BARLOW, Sir WILLIAM OWEN Orielton (d. 1851) - see OWEN
- BARNES, EDWARD (fl. c. 1760-1795), poet and translator of religious books
- BARNES, WALLEY (1920 - 1975), association footballer
- BARNWELL, EDWARD LOWRY (1813 - 1887), antiquary and schoolmaster
- BARRETT, JOHN HENRY (1913 - 1999), naturalist and conservationist
- BARRETT, RACHEL (1874 - 1953), suffragette
- BARRETT, WILLIAM LEWIS (1847 - 1927), flautist