Wenna (Welsh: Gwen) was a medieval princess and Christian martyr who flourished in Wales and Cornwall.

Later venerated as a saint, she is honoured at multiple churches in Cornwall and Devon.

According to the 12th-century Life of Nectan, Wenna was one of the twelve daughters of Brychan, a legendary king of Brycheiniog (modern-day Wales).

[1] Her siblings included Nectan, Mabyn, Ninnoc, and numerous other Brythonic saints.

[5] Wenna may have also had a holy well dedicated to her at St Wenn, but no specific records corroborate this.