Papilio helenus, the red Helen, is a large swallowtail butterfly found in forests of southern India and parts of southeast Asia.
Papilio helenus is rarely found in Sri Lanka, southern and north-east India, Nepal, Bhutan, Bangladesh, Myanmar, Thailand, Laos, Kampuchea, Vietnam, southern China (including Hainan, Guangdong province), Taiwan, southern Japan, South Korea, Ryukyu Islands, peninsular and eastern Malaysia, Brunei, Philippines, and Indonesia (Sumatra, Java, Bangka, Kalimantan, the Lesser Sunda Islands except Tanimbar).
In India it occurs along the Western Ghats from Kerala to Gujarat, also Palnis and Shevaroys, in the north from Mussoorie eastwards, to north-east India and onto Myanmar.