Bannon, of Irish origin, is derived from the Irish surname Ó Bearáin, which means 'descendant of Bearach'. The name Bearach is a diminutive of bear, meaning 'speedy' or 'brave', suggesting that its bearer was swift or courageous. The name Bannon has been present in Ireland since the Middle Ages and has since spread to other countries through immigration.
The name Bannon experienced a notable rise and fall in popularity over time, with peak years being 2016 (16 births) and 2018 (13 births), while the most recent data shows a decline with only 5 births in 2023.