Tarucus is a butterfly genus in the family Lycaenidae.

The delimitation of Castalius versus Tarucus is not yet fully resolved, with some species, such as the dark Pierrot (T. ananda), having been moved between the two genera repeatedly.

It may even be that they are eventually regarded as synonymous, and in that case the older name Castalius would supersede Tarucus by the Principle of Priority.

The caterpillars of this genus typically feed on Ziziphus and are attended by ants.

These are generally separated geographically, but some taxa (such as the black-spotted Pierrot, T. balkanicus nigra), though assigned to one group, occur in the range of the other.