| Official Name: | Pulau Ayau |
| Pushpin Map: | Indonesia Western New Guinea |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Name: |  Indonesia |
| Subdivision Name1: | Southwest Papua |
| Area Land Km2: | 5.06 |
| Timezone: | Eastern Indonesian Time |
| Utc Offset: | +09:00 |
| Coordinates: | 0.3747°N 131.0458°W |
| Pulau Ayu | |
| Location: | South East Asia |
| Coordinates: | 0.3667°N 133°W |
| Archipelago: | Ayu Islands |
| Total Islands: | 5 (2 uninhabited) |
| Major Islands: | Pulau Ayau, Pulau Reni, Pulau Kanobe |
| Country Admin Divisions Title: | Province |
| Country Admin Divisions: | Southwest Papua |
| Ethnic Groups: | Melanesians, Papuans, Austronesians |
Pulau Ayau, often called Pulau Aju or simply Ajoe, is a small Indonesian island located in the Ayau Islands above the northern tip of the Waigeo Islands.
Pulau Ayau is administratively part of the Raja Ampat Regency in the Southwest Papua Province of Indonesia.
The two major settlements on the island include Imbik Kuan and Ayu.
The island is surrounded by two large reefs.
Pulau Reni and Pulau Kanobe are two other small inhabited islands north of Pulau Ayau.
Access to the island is limited to small boats due to the reefs and the small size of the island.
Pulau Ayau and all the islands in the Ayau Archipelago were occupied by the Japanese Empire during World War II from 1942 until the end of the war in 1945.