The standardwing bird-of-paradise (Semioptera wallacii) also known as Wallace's standardwing or as the standardwing is a species of bird-of-paradise. It is the only member in monotypic genus Semioptera.
The standardwing bird-of-paradise is medium-sized, approximately 28 cm long, and olive brown. The male has a gloss violet-and-lilac coloured 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 but has a longer tail than the male.