The Ao Nagas are a major Naga ethnic group native to Mokokchung District of Nagaland, Northeast India. Their main territory is from Tsüla (Dikhu) Valley in the east to Tsürang (Disai) Valley in the west in Mokokchung District. The Ao Nagas refer to themselves as Aoer, which means "those who came" from across the Dikhu river.