Llywelyn is a given name and surname of Welsh origin. See also Llywelyn (name).
Llywelyn may also refer to:
Places Llewellyn, Tasmania, Australia, a village Llewellyn, Pennsylvania, United States, an unincorporated community
Other uses Llewellyn Formation, Pennsylvania, United States, a geologic formation Llewellyn baronets, two titles in the Baronetage of the United Kingdom, one extant Llewellyn Worldwide, a New Age and Occult publishing house Llewellin Setter, a field dog bred from the English Setter by Englishman R. Purcell Llewellin (1840–1925) HMS Llewellyn, two ships of the Royal Navy the title character of Lloyd Llewellyn, comic book series by Daniel Clowes "Llewellyn", a song on the album Marin County Line by New Riders Of The Purple Sage
See also Carnedd Llewelyn, a mountain in Snowdonia, North Wales Llywelyn's coronet, crown seized by Edward I in 1284 Lewellen, Nebraska, a village