Kokoona zeylanica, known in Sinhala as කොකුන් (Kokun) is a species of plant in the family Celastraceae.

It is not to be confused with the similar sounding word කොකුම් which stands for the Kokum plant.

[4] The kokun is a large tree with a rough grey bark.

[3] The kokun is regarded as a medicinal plant traditionally used in a number of conditions.

[3][5] The seed oil from this plant is effective as a leech repellent.