The Wallace's Standardwing, Semioptera wallacii is a medium-sized, approximately 28cm long, olive-brown bird of paradise. It is the only member in monotypic genus Semioptera. The male has a gloss violet-and-lilac colored crown and emerald green breast-shield. Its most striking features are two pairs of long white plumes coming out from the bend of the wing that can be raised or lowered at the bird's will. The unadorned olive-brown female is smaller and has longer tail than male.

George Robert Gray of the British Museum named this species in honor of Alfred Russel Wallace, British naturalist and author of The Malay Archipelago, who discovered the bird in 1858.

Inhabits and endemic to the famed Spice Islands of eastern Indonesia, the Wallace's Standardwing is the westernmost species of the true bird of paradise. The diet consists mainly of insects, arthropods and fruits.

The males are polygamous. They gather and perform a spectacular aerial display, "parachuting" with wings and its vivid green breast shield spread, and the wing "standards" fluttering above its back.

A common species in its limited habitat range, the Wallace's Standardwing is evaluated as Least Concern on the IUCN Red List of Threatened Species. It is listed on Appendix II of CITES.