Iolaus is a genus of butterflies in the family Lycaenidae.

The genera Argiolaus, Epamera, Iolaphilus and Stugeta are often included in Iolaus.

130 species in Iolaus Medium-sized butterflies, hind wing with two long tails.

The undersides are pale greyish-brown, often with a dark transverse line in the dista part or an orange spot at the hind corner of the hindwing.

Most species have larvae that feed onsemi-parasitic plants in the mistletoe family (Viscaceae).