Madau is an island of the Woodlark Islands group, in the Solomon Sea and Milne Bay Province of Papua New Guinea.
It is a few 100m (300feet) off the northwestern tip of Woodlark Island. Its area is 32km2. The highest point is 7m (23feet) above MSL.
At the census of population of 2000, the island hat 758 inhabitants. 307 were in the principal village of Madau, located in the centre of the island; 237 in Muneiveyova in the north; and 178 in Boagis in the south.
There is only one species of mammal on the island, the Woodlark Cuscus (Phalanger lullulae). It is in the Trobriand Islands rain forests ecoregion.