Trigonobalanus is a genus of three species of evergreen trees in the family Fagaceae, related to beeches and chestnuts. The species are widely scattered, with one in northern South America and two in southeast Asia; some botanists treat the three species in separate genera. The three species, with their authors, major synonyms, and distribution, are:

• Trigonobalanus doichangensis (A. Camus) Forman (syn. Formanodendron doichangensis (A. Camus) Nixon & Crepet) - subtropical Yunnan to northern Thailand
• Trigonobalanus excelsa Lozano, Hern. Cam. & Henao (syn. Colombobalanus excelsa (Lozano, Hern. Cam. & Henao) Nixon & Crepet) - endemic to Colombia
• Trigonobalanus verticillata Forman - tropical Indonesia and the Malay Peninsula