Schildia Aldrich, 1923, a distinctive and rare genus of leptogastrine flies (Diptera: Asilidae), is revised. Twelve valid species are recognized, of which four are new to science. The nine extant species are Neotropical in distribution. They are S. microthorax Aldrich, 1923, S. fragilis (Carerra, 1944), S. gracillima (Walker, 1855), S. jamaicensis Farr, 1963, S. alphus Martin, 1975, S. zonae Martin, 1975, S. guatemalae Martin, 1975, and S. ocellata Martin, 1975. One species is newly described from southern Venezuela. Three extinct species of Schildia are newly described. Of these, two are described from Dominican amber (approximately 30 million years ago), and one is described from copal from Madagascar(1000-10000 years ago). The type specimens of S. ocellata and S. guatemalae are declared lost. The species concepts of S. ocellata and S. guatemalae are unclear, therefore redescriptions of seven extant species are provided, along with descriptions of the fossil species. An identification key to the extant and fossil species is presented. Illustrations, photographs, and scanning electron micrographs are provided to support the descriptions and key. Distribution, biogeography, occurrence in biodiversity hotspots, seasonal incidence, and biology are discussed. The geographic distributions of several species are expanded. Potential reasons are explored to explain why a species of Schildia, otherwise strictly Neotropical, is the only leptogastine found in Malagasy copal. Further discussion addresses why this species has not been found in extant fauna after the extensive study of museum specimens. Tentative minimum age of the genus is discussed in light of new fossil and biogeographical data.