Gigasiphon is a genus of plants in the family Fabaceae. The genus is circumscribed is defined by "a long-tubular hypanthium, an arborescent habit, and a calyx divided into two lobes". It includes five species native to eastern Africa, Madagascar, the Philippines, New Guinea, and Lesser Sunda Islands.
Gigasiphon comprises the following species:
Note: Gigasiphon gossweileri is now in the African monotypic genus Tournaya