Praepapilio is an extinct genus of swallowtail butterfly from the middle Eocene deposits of Colorado, United States, comparable to the Lutetian epoch in age. The genus is considered to be the only representative of the fossil subfamily Praepapilioninae. Praepapilio is, so far, the only wholly extinct subtaxon known within the swallowtail family. Two species have been described, each from a single fossil find.