Banu Bakr bin Wa'il or Banu Bakr, son of Wa'il ( ) were an Arabian tribe belonging to the large Rabi'ah branch of Adnanite tribes, which also included 'Anizzah, Taghlib, and Bani Hanifa. The tribe is reputed to have engaged in a 40-year war before Islam with its cousins from Taghlib, known as the War of Basous. The pre-Islamic poet, Tarafah was a member of Bakr.