Papilio is a genus in the swallowtail butterfly family, Papilionidae. It includes a number of well-known North American species such as the Western Tiger Swallowtail, Papilio rutulus.
Older classifications of the swallowtails tended to use a large number of rather small genera. More recent classifications have been more conservative, and as a result a number of former genera are now absorbed within Papilio. The genus as recognized by modern systems has about 200 members.