Henwen, meaning "Old White", is in Welsh legend a sow (female pig) which according to the Welsh Triads gave birth to Cath Palug, a monstrous cat depicted as combating with either Cai ( Sir Kay) or King Arthur of Arthurian Legends. According to the triad "Three Powerful Swinherds of the Isle of Britain", the sow was kept by one Coll, son of Collfrewy, a pigkeeper for Dallwyr Dallben (also spelt Dallweir). The variant Red Book of Hergest (RBH) and White Book of Rhydderch (WBR) texts add that the Dallwyr held a valley named after him, the Glen of Dallwyr in Cornwall. The sow was ready to give birth, but this boded ill for the Isle of Britain, according to prophecy, so she was chased until she plunged into the sea at Penrhyn Awstin in Cornwall. The sow eventually re-emerges on land at Aber Tarogi in Gwent Is-coed (a subdivision of Gwent).
Henwen may refer to:
- Henwen, a mythical Welsh sow
- Hen Wen, a fictional sow in Lloyd Alexander's The Chronicles of Prydain