| Wanim Island | |
| Native Name Lang: | png |
| Sobriquet: | Grass Island |
| Pushpin Map: | Papua New Guinea |
| Coordinates: | -11.2633°N 153.2589°W[1] |
| Location: | Oceania |
| Archipelago: | Louisiade Archipelago |
| Waterbody: | Solomon Sea |
| Total Islands: | 1 |
| Area Km2: | 1.66 |
| Coastline M: | --> |
| Elevation M: | 119 |
| Highest Mount: | Mount Wanim |
| Country: | Papua New Guinea |
| Country Admin Divisions Title: | Province |
| Country Admin Divisions Title 1: | District |
| Country Admin Divisions 1: | Samarai-Murua District |
| Country Admin Divisions Title 2: | LLG[2] |
| Country Admin Divisions 2: | Yaleyamba Rural Local Level Government Area |
| Country Admin Divisions Title 3: | Island Group |
| Country Admin Divisions 3: | Pana Tinani Group |
| Country Largest City: | Bunbun |
| Country Largest City Population: | ~450 |
| Population: | 600 |
| Population As Of: | 2014 |
| Density Km2: | 361 |
| Ethnic Groups: | Papauans, Austronesians, Melanesians. |
| Timezone1: | AEST |
| Utc Offset1: | +10 |
| Iso Code Type: | ISO code |
| Iso Code: | PG-MBA |
Wanim Island is an island in the Louisiade Archipelago in Milne Bay Province, Papua New Guinea.
The island has an area of 3.56 km2 and is part of the Pana Tinani Group. The island is hilly, rising to 119 m at Mt. Wanim.The island is 0.9 km south of Pana Tinani and separated from it by the Bulami Channel.
The island was discovered in the late 18th century.
At the census of population in 2014, the island had 600 inhabitants, spread across 3 small villages. The main town is Bunbun, located on the northwest point.