Vanimo is the capital of Sandaun Province in north-westernmost Papua New Guinea and of Vanimo-Green River District. It is located on a peninsula close to the border with Indonesia, nearest to Jayapura, the capital city of Papua (province).

The Indonesia–Papua New Guinea border is the international border between Indonesia and Papua New Guinea. The border, which divides the island of New Guinea in half, consists of two straight north–south lines connected by a short section running along the Fly river, totalling 824 km (512 mi). The boundary separates Papua, Highland Papua, and South Papua provinces of Indonesia from Sandaun and Western provinces of Papua New Guinea.