Nephelium cuspidatum, also known as rambutan hutan in Malay and buah sibau in Iban, is a species of flowering plant, a tropical forest fruit-tree in the rambutan family, that is native to Southeast Asia.

[2] Varieties include:[2] The species grows as a tree to 40 m in height with a 3–6 m bole and small buttresses.

The pinnate leaves have 2–13 pairs of oval to oblong leaflets.

The inflorescences consist of spikes or racemes of pink and white flowers.

[2] The species occurs over a wide range extending from Myanmar to Thailand, Cambodia, Vietnam, the Philippines, the Malay Peninsula, Borneo, Sumatra and Java.