Cotylelobium melanoxylon is a tree in the family Dipterocarpaceae. The specific epithet melanoxylon means "black wood", referring to the dark colour of the tree's wood. It was first described by Joseph Dalton Hooker in 1860 as Anisoptera melanoxylon and transferred to Cotylelobium by Jean Baptiste Louis Pierre in 1889. It is the provincial tree of Surat Thani Province, Thailand.
Cotylelobium melanoxylon grows up to 60m (200feet) tall, with a trunk diameter of up to 1.50NaN0. The leathery leaves are lanceolate or ovate or oblong and measure up to 10cm (00inches) long. The inflorescences measure up to 8cm (03inches) long and bear cream flowers.
Cotylelobium melanoxylon is native to Thailand, Peninsular Malaysia, Sumatra and Borneo. Its habitat is in kerangas and mixed dipterocarp forests, at elevations up to 750m (2,460feet).