The standardwing bird-of-paradise, 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 birds-of-paradise are members of the family Paradisaeidae of the order Passeriformes. The majority of species are found in eastern Indonesia, Papua New Guinea, and eastern Australia. The family has 45 species in 17 genera. The members of this family are perhaps best known for the plumage of the males of the species, the majority of which are sexually dimorphic. The males of these species tend to have very long, elaborate feathers extending from the beak, wings, tail, or head. For the most part, they are confined to dense rainforest habitats. The diet of all species is dominated by fruit and to a lesser extent arthropods. The birds-of-paradise have a variety of breeding systems, ranging from monogamy to lek-type polygamy.