Gruffydd ap Llywelyn Fawr, Welsh noble, son of Llywelyn the Great (born 1200)

Gruffudd ap Llywelyn ab Iorwerth was a Welsh prince, and the first-born son of Llywelyn ab Iorwerth. His mother Tangwystl probably died in childbirth.

Llywelyn ab Iorwerth, also known as Llywelyn the Great, was a medieval Welsh ruler. He succeeded his uncle, Dafydd ab Owain Gwynedd, as King of Gwynedd in 1195. By a combination of war and diplomacy, he dominated Wales for 45 years.