- LACY (DE) family, lords Ewyas, Weobley,
- LACY (DE) family, constables of Chester Halton,
- Ladies of Llangollen - see BUTLER, Lady ELEANOR CHARLOTTE
- Ladies of Llangollen - see PONSONBY, SARAH
- Lady Mackworth - see THOMAS, MARGARET HAIG
- Lady Rhondda - see THOMAS, MARGARET HAIG
- LAKE, MORGAN ISLWYN (1925 - 2018), minister and pacifist
- LANG, GORDON (1893 - 1981), Labour politician and nonconformist minister
- LANGFORD family Allington,
- LANGFORD, JOHN (1640? - 1715/6?)
- LATHROP, RICHARD (d. 1764), bookseller and printer
- LAUGHARNE, ROWLAND (d. 1676?), Parliamentary major-general
- LAWS, EDWARD (1837 - 1913), historian
- LEACH, ARTHUR LEONARD (1869 - 1957), historian, geologist and archaeologist
- LEANDER - see JONES, JOHN
- LEATHART, WILLIAM DAVIES (d. after 1840), historian of the Gwyneddigion Society of London
- LEE, ROWLAND (d. 1543), bishop of Coventry and Lichfield (which included at that time what later became the diocese of Chester) (1534-1543), and president of the Council in Wales and the Marches for the same period
- LEEKE, SAMUEL JAMES (1888 - 1966), Baptist minister
- LEFIAD, Y - see WILLIAMS, WILLIAM
- LEGH, ROWLAND - see LEE, ROWLAND
- LEIF-JONES, LEIFCHILD STRATTEN - see JONES, LEIFCHILD STRATTEN LEIF
- LEIGH, EDMUND (1735? - 1819), Methodist cleric
- LEIGHTON of St. Mellons, 1st Baron - see SEAGER, GEORGE LEIGHTON
- LEILA MEGĂNE - see HUGHES, MARGARET
- LEO - see WILLIAMS, JOHN HUW
- LESTRANGE family Great Ness, Cheswardine, Knockin,
- LEVI PHILLIPS, SAMUEL - see PHILLIPS, SAMUEL LEVI
- LEVI, SAMUEL - see PHILLIPS, SAMUEL LEVI
- LEVI, THOMAS (1825 - 1916), Calvinistic Methodist minister, editor of Trysorfa y Plant, and author
- LEVI, THOMAS ARTHUR (1874 - 1954), professor of law
- LEVY, MERVYN MONTAGUE (1914 - 1996), writer and broadcaster on the visual arts
- LEWELLIN, LLEWELYN (1798 - 1878), cleric
- LEWES, DAVID - see LEWIS, DAVID
- LEWES, ERASMUS (1663? - 1745), cleric
- LEWES, EVELYN ANNA (c. 1873 - 1961), author
- LEWES, Captain JOHN - see LEWES, ERASMUS
- LEWES, Sir WATKIN (1740 - 1821), lord mayor of London
- LEWES, WILLIAM (1652 - 1722), landowner and antiquary
- LEWIS family Van,
- LEWIS family Llwyn-du, Llangelynnin
- LEWIS family, printers and publishers
- LEWIS, Harpton - see HARLEY
- LEWIS ab EDWARD (fl. c. 1560), poet
- LEWIS ap GWATCYN, landowner - see VAUGHAN
- LEWIS ap WATKIN, landowner - see VAUGHAN
- LEWIS DARON (fl. c. 1520), a poet
- LEWIS GLYN COTHI (fl. 1447-1486), one of the greatest of the 15th century Welsh bards
- LEWIS GLYN CYNON - see DAVIES, LEWIS
- LEWIS HUDOL (fl. 16th century), poet
- LEWIS LLOYD, EMMELINE (1827 - 1913), one of the first women to climb in the Alps