David or Dafydd ap Gruffydd (c. 1235–October 3, 1283) was Prince of Wales from December 1282 until his his capture in 1283. Following the death of his brother, Llywelyn ap Gruffydd, he was the last free Welsh ruler of Wales, except for periods of rebellion.

He was a prince of Gwynedd, a younger son of Gruffydd ap Llywelyn and his wife, Senena, and thus grandson of Llywelyn the Great. During his career, Dafydd had repeatedly switched allegiances between his elder brother Llywelyn and King Edward I of England, but it was his rash attack on Hawarden Castle in March 1282, that caused the final conflict with Norman England , in the course of which Welsh independence was lost. The last prince of Gwynedd and Wales, he ruled only for a few months after Llywelyn's death, effectively an outlaw. Seeking refuge from the English forces in the mountains of Gwynedd, he was eventually captured and executed at Shrewsbury, and is identified by some sources as the first victim of the punishment for a new crime, high treason. He died via disembowelment, having his intestines seared with a hot iron, hanging, and drawing and quartering.

Dafydd had been married to Elizabeth Ferrers, daughter of William de Ferrers, 5th Earl of Derby. Their daughter Gwladys, like her cousin Princess Gwenllian, was sent to the convent of Sixhills where she died in 1336. Their sons were both imprisoned at Bristol Castle ; Llywelyn died in March 1338, while Owain is last found living in August 1325.