Gráinne is the daughter of Cormac mac Airt in the Fenian Cycle of Irish mythology. She is one of the central figures in the Middle Irish text Finn and Gráinne and most famously, in the 17th-century tale The Pursuit of Diarmuid and Gráinne, which tells of her betrothal to Fionn mac Cumhaill, leader of the Fianna, and her subsequent elopement with Fionn's warrior Diarmuid Ua Duibhne.