Papilio demodocus, the citrus swallowtail or Christmas butterfly, is a swallowtail butterfly which commonly occurs over the entirety of sub-Saharan Africa, including Madagascar, besides the southern Arabian Peninsula. The caterpillars feed on various native plants of especially the family Rutaceae, but have also taken to the leaves of cultivated citrus trees.

Swallowtail butterflies are large, colorful butterflies in the family Papilionidae, and include over 550 species. Though the majority are tropical, members of the family inhabit every continent except Antarctica. The family includes the largest butterflies in the world, the birdwing butterflies of the genus Ornithoptera.