Aífe (Old Irish, spelled Aoife in Modern Irish, Irish pronunciation: [ˈiːfʲə]) is a character from the Ulster Cycle of Irish mythology. She appears in the sagas Tochmarc Emire ("the wooing of Emer") and Aided Óenfhir Aífe ("the death of Aífe's only son"). In Tochmarc Emire she lives east of a land called Alpi, usually understood to mean Alba (Scotland), where she is at war with a rival woman warrior, Scáthach. In Aided Óenfhir Aífe she lives in Letha (the Armorican peninsula), and is Scáthach's sister as well as rival – they are both daughters of Árd-Greimne of Lethra.