Notogomphus maathaiae sp. nov. (holotype ♂: Kenya, Western Province, Mt Elgon District, Mt Elgon, Rongai River, 2,361 m a.s.l., 1°02′19.4″N, 34°45′20.5″E, 06 vi 2000) is described from a series of 8 males and 3 females collected at montane forest streams in Kenya. The status and biogeography of this and other montane species are discussed.