Gnathothlibus collardi is a moth of the Sphingidae family. It is a hybrid between a female Philodila astyanor and a male Gnathothlibus eras. It is known from Tahiti.The length of the forewings is about 35 millimetres (1.4 in). It is similar to Gnathothlibus eras but the forewings are rather more similar to Gnathothlibus saccoi and the hindwings are identical to Gnathothlibus dabrera. The forewing outer margin is slightly angled.