Magnolia napoensis, a new species from the Amazonian lowlands of Ecuador and Peru is described and illustrated. This species belongs to subsection Talauma; it is similar to M. rimachii in leaf shape but differs from the latter in being taller with a larger diameter and having fewer lateral leaf veins, more numerous hypsophylls, larger flowers, longer outer petals, more numerous stamens and fruits ovoid and ribbed vs. subglobose and smooth. The new species differs from M. neillii by its leaves with fewer lateral veins, glabrous petioles and terminal internodes, more numerous hypsophylls, fewer stamens and ovoid fruits of smaller size, with fewer carpels. Magnolia napoensis is assessed as endangered (EN B2ab(iii)) in accordance with the IUCN criteria.