Saint Ninnoc or Ninnog of Breton, also known as Nenooc, Nennoca, Nennocha, Ninnoc, Ninnocha, and Gwengustle, was an early medieval abbess born in Wales who died in Brittany. The text of Vita Sanctae Ninnocae, preserved in the Cartulary of Quimperlé, provides knowledge of her life and work.