A new species of Malvaceae, Spirotheca zapotillana , is described from the Equatorial Pacific region of South America. The species occurs in seasonally dry tropical forests of El Oro and Loja provinces in southern Ecuador. It is characterized by a strictly tree-like habit, elliptical leaflets with acute apices, glandular floral receptacles, glabrous styles, oblong capsules, and reniform seeds. A morphological description of the new species is provided, along with data on its habitat and distribution, an assessment of its conservation status, and an updated key for the genus.