Eurytides thyastes is a species of butterfly found in the Neotropical realm.

Eastern slopes of the Andes from North Ecuador to Central Peru, Upper Amazon.

[synonym of thyastinus] Like the preceding; the 1. submarginal spot of the forewing sharply- defined; the discal spot between 2. radial and 1. median usually truncate distally, the upper angle not rounded.

Paler yellow than the Andes forms; discal band of the forewing not interrupted, or only very slightly, the submarginal spot between the 2. and 3. radials quite close to the discal spot or partly merged with it; the black discal area of the hindwing not entering the cell.

Southern Brazil, only known from São Paulo to Rio Grande do Sul.