| Ātiu or Middle Island | |
| Coordinates: | -36.6378°N 175.86°W |
| Country: | New Zealand |
| Country Admin Divisions Title: | Region |
| Country Admin Divisions: | Waikato |
| Population: | uninhabited |
Ātiu or Middle Island, also known as Atiu Island, or Middle Island, is an island in the middle of the Mercury Islands of New Zealand. Ātiu means "wandering about" and is the original Māori language name for the island. It was assigned its current dual name in December 1994.[1]