Papilio iswara, the great Helen, is a species of large swallowtail butterfly found in parts of Southeast Asia.

The female paler than the male, the red submarginal spots larger on both surfaces.

The genitalia similar to those of P. helenus, the harpe of the more spoon-shaped and the infra-anal processes shorter.

The white area of the hindwing posteriorly broad; the yellow-red spots of the underside of the hindwing large, the anterior ring-spot also in the male entire, the black pupils of both the eye-spots in the female small.

The members of this clade are: The holotype is conserved in the Natural History Museum, London.