Vatica rassak is a tree in the family Dipterocarpaceae, native to Maritime Southeast Asia. The specific epithet rassak is from , the species' Malay common name.
Vatica rassak grows up to tall, with a trunk diameter of up to . Its coriaceous leaves are elliptic to oblong and measure up to long. The inflorescences bear cream flowers. In Borneo, a newly discovered, unnamed special caterpillar makes use of the poisonous resin from this tree to build a cocoon.
Vatica rassak is native to Borneo, Java, the Maluku Islands, Sulawesi, New Guinea and the Philippines. Its habitat is along rivers and in lowland dipterocarp forest, at altitudes to .