Saint Gwen Teirbron (French: Blanche; Latin: Alba Trimammis or Candida; possibly English: Wite) was a Breton holy woman and wife of Saint Fragan who supposedly lived in the 6th century. Her epithet is Welsh for '(of the) three breasts'.
Popular devotion interpreted Gwen's unusual physical and spiritual fecundity by God's gift to her of a third breast. Her iconography naïvely followed suit. Gwen is invoked for women's fertility. She is commemorated on 3 October in the Catholic Church (although this has been transferred from Saint Candidus of Rome), and on 18 July (NS) by the Russian Orthodox Church Abroad in Australia.