The Kingdom of Breifne or Bréifne (anglicized "Breffny", "Brefnie" or "Brenny") was the traditional territory for an early Irish tribal group known as the Uí Briúin Bréifne.
Il regno di Bréifne (anche "Breffny", "Brefnie", "Brenny") era il tradizionale territorio del gruppo tribale degli Uí Briúin Bréifne.