Heliconius antiochus, the Antiochus longwing, is a butterfly of the family Nymphalidae. It was described by Carl Linnaeus in 1767. It is found from Panama to the Amazon region. The habitat consists of riparian forests. Adults have blue-black wings with two transverse white or yellow bands on the distal part of the forewings. They are a Müllerian mimic of Heliconius wallacei, Heliconius sara and . The larvae are gregarious and mostly feed on Passiflora species from the subgenus . Full-grown larvae have a yellow body with a black head and reach a length of about 12 mm.