Parnassius simonius is a high-altitude butterfly which is found only in the Pamir Mountains of Central Asia. The type locality is Aram-Kunghei, Zaalaisky Mountains, Kyrgyzstan. It is a member of the snow Apollo genus (Parnassius) of the swallowtail (Papilionidae) family.
P. simonius is found on slopes at 3,400-4,500 m flying in July. The larva is associated with Lagotis decumbens and Veronica luetkeana.
P. simo differs from P. simonius by the upper hindwing having its submarginal band represented by a discontinuous row of arrow-like teeth and from P. boedromius, by the upper hindwing submarginal band being smoothly dentate (tooth like).