Richard Llewellyn (1906-1983), English author of Welsh descent

Llewellyn, Pennsylvania, a community in eastern Pennsylvania

Llewelyn Powys (1884 - 1939), British writer

Llywelyn the Great (Llywelyn ab Iorwerth) (c.1173–1240), Prince of Gwynedd and ruler of most of Wales

Historically it may refer to any of several Welshmen:

Llywelyn the Last (c. 1228-1282), the last crowned Welsh Prince of Wales

Morgan Llywelyn (1937- ), American historical author

Officer Francis Llewellyn 'Ponch' Poncherello, a fictional character of the American television series CHiPs

Sir William Llewellyn (1858-1941) English painter and President of the Royal Academy

Carnedd Llewelyn, a mountain in Snowdonia, Wales

John Dillwyn Llewelyn (1810–1882), Welsh botanist and photographer

John Llewellyn Rhys Prize, a British based literary prize initiated in 1942

Charles Llewellyn (1876-1964), first non-white South African Test cricketer

Laurence Llewelyn-Bowen (1965- ), interior designer and television personality

Llewellyn Formation, a geologic formation in eastern Pennsylvania

W. Llewelyn Williams (1867-1922), Welsh journalist, lawyer and politician

Llewellyn Baronets

Llewellyn Thompson (1904-1972), American diplomat

Llewellyn Worldwide, a New Age and Occult publishing house

Llewellyn Powers (1836-1908), member of the US House of Representatives from Maine

Harry Llewellyn (1911-1999), British equestrian champion

Robert Llewellyn (1956- ), English actor, presenter, and writer

Llywelyn ap Dafydd (c.1260-1288), the heir to the Welsh crown imprisoned in 1283

Llewellyn Henry Gwynne (1863-1957), first Bishop of Egypt and Sudan

Llywelyn Bren (d. 1318), a nobleman who led a Welsh rebellion in 1316

Llewellyn Atherley-Jones (1851-1929), British politician and judge

Llewellyn Xavier (1945- ), Saint Lucian artist

Roddy Llewellyn (1947- ), British landscape gardener, author, and television presenter

David Llewellyn (1978- ) Welsh author of Eleven

Gareth Llewellyn (1969- ), Welsh rugby union player

Peter Rodney Llewellyn (1947- ), English businessman and alleged fraduster

Lloyd Llewellyn, comic book series by Daniel Clowes

Llewelyn Lewellin (1798–1878), British cleric and university educator

Llewellyn Turner (1823-?), Welsh politician

Llewellyn John Montfort Bebb (1862-1915), British academic

Sir Christopher Llewellyn Smith (physicist), British physicist

Llewellyn Woodward (1890-1971), British historian

Llewellyn Herbert (1977- ), South African athlete

Edward Llewellyn (1917-1984), Canadian professor

Llewelyn Kenrick (1847-1933), Welsh international footballer

Llywelyn Williams (1911-1965), Welsh politician

Llewellyn Thomas Smith (Llew Smith) (1944- ), Welsh politician

David Llewellyn (multiple persons)

Llywelyn Goch ap Meurig Hen (c.1350-1390), Welsh poet

Evan Henry Llewellyn (1847–1914), British politician

Llewelyn Wyn Griffith (1890-1977), Welsh novelist

Chris Llewellyn (1979- ), Welsh footballer

Llywelyn ab Y Moel (d. 1440), Welsh poet

Llywelyn Siôn (c. 1540-1615), Welsh poet

Dafydd ap Llewelyn (multiple persons)

Llewellyn Price (1905-1980), Brazilian paleontologist

Llewelyn Williams (multiple persons)

The Welsh name Llywelyn (IPA: [ɬə'wɛlɪn]) most likely derives from Old British Lugubelenus, a compound word formed from the names of the Celtic gods Lug or Lugh and Belenus. It is sometimes spelt Llywellyn, Llewelyn or Llewellyn (the doubling of the second -l- is by analogy; the name is never pronounced IPA: [ɬəw'ɛɬɪn]).

Llywelyn ap Merfyn (d. 942) early 10th century King of Powys

Llywelyn ap Seisyll (d. 1023), king of Gwynedd and Deheubarth

Llywelyn ap Maredudd ap Llywelyn ap Maredudd ap Cynan (d. 1263), minor Welsh prince, last vassal Lord of Meirionydd

Llywelyn ap Gruffydd Fychan (1341-1401), a Welsh landowner executed for assisting Owain Glyndŵr's escape from English forces

Sylvia Llewelyn Davies (1866-1910) and her children (the "Llewelyn Davies boys"), the namesakes of the characters in Peter Pan

Desmond Llewelyn (1913-1999), Welsh actor who played Q in the James Bond series of films

Grace Llewellyn (?- ), Welsh author of several books on homeschooling

Karl N. Llewellyn (1893-1962), American jurisprudential scholar associated with the school of legal realism

Doug Llewelyn, Host of The People's Court

Llewellyn Edwards (1935- ), Australian politician and chancellor of the University of Queensland

Llewelyn Alberic Emilius Price-Davies (1878-1965), British soldier and recipient of the Victoria Cross

Llewellyn Vaughan-Lee (1953- ), British Sufi mystic and author

Llewellyn Park, a neighborhood in West Orange, New Jersey, founded in 1853 by Llewellyn Solomon Haskell

Llywelyn's coronet, crown seized by Edward I in 1284