Táin Bó Flidhais, also known as the Mayo Táin, is a tale from the Ulster Cycle of early Irish literature. It is one of a group of works known as Táin Bó, or "cattle raid" stories, the best known of which is Táin Bó Cúailnge. Táin Bó Flidhais survives in two forms, a short version from the Old Irish period and a longer version found in the 15th century Glenmasan manuscript, which is held in the Advocates Library in Edinburgh. It is believed to be a copy of an earlier manuscript from the 12th century. The early version of Táin Bó Flidhais predates the Táin Bó Cúailnge. It is named for the heroine of the tale, Flidais.

The Ulster Cycle, formerly known as the Red Branch Cycle, is a body of medieval Irish heroic legends and sagas of the Ulaid. It is set far in the past, in what is now eastern Ulster and northern Leinster, particularly counties Armagh, Down and Louth. It focuses on the mythical Ulster king Conchobar mac Nessa and his court at Emain Macha, the hero Cú Chulainn, and their conflict with the Connachta and queen Medb. The longest and most important tale is the epic Táin Bó Cúailnge. The Ulster Cycle is one of the four 'cycles' of Irish mythology and legend, along with the Mythological Cycle, the Fianna Cycle and the Kings' Cycle.