Ida de Grey or Edith de Grey (1368 – 1 June 1426), was a Cambro-Norman noblewoman, and the daughter of Reginald Grey, 2nd Baron Grey de Ruthyn, a powerful Welsh Marcher lord. The Greys of Ruthyn were the chief Marcher barons in the northern region of the Welsh Marches. Ida married Sir John Cokayne, Justice of the Common Pleas, by whom she had six children. Through her eldest daughter Elizabeth, she was an ancestress of Anne Boleyn, Jane Seymour, and Catherine Howard, queens consort of King Henry VIII of England.