Didymocheton alliaceus is a species of flowering plant in the mahogany family, Meliaceae.

It is a tree native to the tropical Pacific islands, ranging from the Solomon Islands to the Caroline Islands, Vanuatu, Fiji, Wallis and Futuna, Niue, Tonga, and the Samoan Islands.

[1] It is most closely related to Didymocheton mollissimus of Malesia and mainland Southeast Asia, D. mollis of the Bismarck Archipelago, New Guinea, and Sulawesi, and D. muelleri of northeastern Australia.

[2] The species was first described as Trichilia alliacea by Georg Forster in 1786.

It was reclassified as Didymocheton alliaceus in 2021.