Llywelyn is a name of Welsh origin, with many spelling variations (see Llywelyn (name)).
Historically the name may refer to any of several Welshmen:
Llywelyn ap Merfyn (died 942) early 10th century King of Powys
Llywelyn ap Seisyll (died 1023), king of Gwynedd and Deheubarth
Llywelyn the Great (Llywelyn ab Iorwerth) (c. 1173 – 1240), Prince of Gwynedd and ruler of most of Wales
Llywelyn ap Maredudd ap Llywelyn ap Maredudd ap Cynan (died 1263), minor Welsh prince, last vassal Lord of Meirionydd
Llywelyn ap Gruffudd (c. 1228 – 1282), the last crowned Welsh Prince of Wales
Llywelyn ap Dafydd (c. 1260 – 1288), the heir to the Welsh crown imprisoned in 1283
Llywelyn Bren (died 1318), nobleman who led a Welsh rebellion in 1316
Llywelyn ap Gruffydd Fychan (1341–1401), Welsh landowner executed for assisting Owain Glyndŵr's escape from English forces
A number of Welsh language poets:
Llywelyn Goch ap Meurig Hen (c. 1350 – 1390), Welsh poet
Llywelyn ab Y Moel (died 1440), Welsh poet
Llywelyn Siôn (c. 1540 – 1615), Welsh poet
More recent bearers of the surname include:
Carmen Llywelyn, American actress and photographer
Chris Llewellyn, American poet
David Llewellyn (born 1978), Welsh author of Eleven
Desmond Llewelyn (1914–1999), Welsh actor who played Q in several James Bond films
Grace Llewellyn, American author of several books on homeschooling
Laurence Llewelyn-Bowen (born 1965), interior designer and television personality
Llewellyn (born Jamie Trott), New Age musician
Morgan Llywelyn (born 1937), U.S.-born Irish historical author
Olivia Llewellyn (born 1980), English actress
Richard Llewellyn (1906–1983), English author of Welsh descent
Robert Llewellyn (born 1956), English actor, presenter, and writer
Roddy Llewellyn (born 1947), British landscape gardener, author, and television presenter
Roger Llewellyn, British actor
Sylvia Llewelyn Davies (1866–1910), and her children (the "Llewelyn Davies boys"), namesakes of the characters in Peter Pan
Sir William Llewellyn (1858–1941), English painter and President of the Royal Academy
Evan Henry Llewellyn (1847–1914), British politician
W. Llewelyn Williams (1867–1922), Welsh journalist, lawyer and politician
Karl Llewellyn (1893–1962), American jurisprudential scholar associated with the school of legal realism
Royce R. Lewellen, California Superior Court judge
Bert Llewellyn (1939–2016), English footballer
Carl Llewellyn (born 1965), Jockey and trainer
Charlie Llewellyn (1876–1964), first non-white South African Test cricketer
Chris Llewellyn (born 1979), Welsh footballer
Gareth Llewellyn (born 1969), Welsh rugby union footballer
Harry Llewellyn (1911–1999), British equestrian champion
Steve Llewellyn (1924–2002), Welsh rugby league footballer
Willie Llewellyn, (1878–1973) Welsh international rugby captain
John Dillwyn Llewelyn (1810–1882), Welsh botanist and photographer
Edward Llewellyn-Thomas (1917–1984), Canadian professor
Peter Rodney Llewellyn (born 1947), English businessman & international con artist.
Doug Llewelyn (born 1938), original host of The People's Court
David Llewellyn (disambiguation) (multiple persons)
Dafydd ap Llewelyn (disambiguation) (multiple persons)
Reese J. Llewellyn (c. 1862–1936), Welsh-born American businessman.
Bearers of the given name include:
Llewelyn Powys (1884–1939), British writer
Llewellyn Woodward (1890–1971), British historian
Llewelyn Wyn Griffith (1890–1977), Welsh novelist
Llewellyn Xavier (born 1945), Saint Lucian artist
Llewellyn Turner (1823–?), Welsh politician
Llewellyn Powers (1836–1908), member of the US House of Representatives from Maine
Llewellyn Atherley-Jones (1851–1929), British politician and judge
Llewellyn Thompson (1904–1972), American diplomat
Llewellyn Edwards (born 1935), Australian politician and chancellor of the University of Queensland
Llewellyn Thomas Smith (Llew Smith) (born 1944), Welsh politician
Llywelyn Williams (1911–1965), Welsh politician
Llewellyn H. Rockwell, Jr. (born 1944), American libertarian political commentator
Llewelyn "Alan" Curbishley (born 1957), English football manager for West Ham United
Llewelyn Kenrick (1847–1933), Welsh international footballer
Llewellyn Herbert (born 1977), South African athlete
Llewellyn Starks (born 1967), American long jumper
Llewelyn Lewellin (1798–1878), British cleric and university educator
Llewellyn John Montfort Bebb (1862–1915), British academic
Llewellyn Henry Gwynne (1863–1957), first Bishop of Egypt and Sudan
Llewelyn Alberic Emilius Price-Davies (1878–1965), British soldier and recipient of the Victoria Cross
Llewellyn Ivor Price (1905–1980), Brazilian paleontologist
Llewellyn Morris Chilson (1920–1981), United States Army career soldier who served heroically in the European Theater of Operations
Llewellyn Vaughan-Lee (born 1953), British Sufi mystic and author
Sir Christopher Llewellyn Smith, British physicist
Llewellyn Thomas, British physicist and applied mathematician
Llewelyn Williams (disambiguation) (multiple persons)
Fluellen, a Welshman from Shakespeare's history Henry V
Llewelyn Moss, a character in Cormac McCarthy's No Country for Old Men
Llewelyn, a young archer in Valkyrie Profile
Officer Francis Llewellyn 'Ponch' Poncherello, fictional character on the U.S. television series CHiPs
CSI supervisor head of NYPD crime lab McKenna Llewellyn 'Mac' Taylor on the U.S television series "CSI:NY"
Llewellyn, an anthropomorphic dragon from the comic Ozy and Millie.
Jesper Llewellyn Fayhey, a character from Leigh Bardugo's Six of Crows duology.
