Arhopala irregularis is a butterfly in the family Lycaenidae. It was described by George Thomas Bethune-Baker in 1903. It is found in Sulawesi and Banggai in the Australasian realm.
irregularis is similar to the preceding species, but considerably larger, the marking beneath also very irregular, though not so variegated as in abseus; the male above has a broader dark marginal band and a very dark blue on the upper surface.