Gwenllian (or Gwenllïan) is a Welsh given name, a combination of gwen "fair, blessed, white" and llian "flaxen").
It is most prominently known as the name of two women in medieval Wales who have, for different reasons, become symbols of Welsh patriotism and/or independence.
Gwenllian is the name of a song by prominent Welsh songwriter Meic Stevens and Anglesey rock band Calfari, based on Gwenllian ferch Gruffydd.
It is also the name of the summit Carnedd Gwenllian in the Carneddau, named after Gwenllian ferch Llywelyn.
A character in The Raven Cycle by American author Maggie Stiefvater is named Gwenllian.