Brycheiniog was a small independent petty kingdom in South Wales in the Early Middle Ages. It can also refer to:
Places Fan Brycheiniog, highest peak in the Black Mountain region of the Brecon Beacons National Park in South Wales Theatr Brycheiniog theatre in Brecon Bannau Brycheiniog, Welsh name for Brecon Beacons, Wales Bannau Brycheiniog National Park, alternative name for Brecon Beacons National Park, Wales Welsh name for Borough of Brecknock, Wales People Gwynfardd Brycheiniog (fl. c. 1170-80), Welsh poet Brychan (or Brychan Brycheiniog), legendary 5th-century king of Brycheiniog Other Brycheiniog (journal), journal founded in 1955 and published by the Brecknock Society and Museum Friends