Onn is the Irish name of the seventeenth letter of the Ogham alphabet.
Onn or ONN may also refer to:
Optical neural network Oscillatory neural network Onion News Network ONN (radio), the Ohio News Network Onn Abu Bakar, a Malaysian politician Onn Jaafar, a Malayan politician Onn Hafiz Ghazi, a Malaysian politician Melanie Onn, a British politician Shmuel Onn, a mathematician Onn, a Walmart store brand of consumer electronics The Festival City of Onn, a later name for Arrakeen, capital of Arrakis in Frank Herbert's novel God Emperor of Dune