Erebia ligea, the Arran brown, is a member of the subfamily Satyrinae of the family Nymphalidae.

This species was first described by Carl Linnaeus in his 1758 10th edition of Systema Naturae, and the type locality is Sweden.

The upperside of both the forewings and hindwings is dark greyish brown with a reddish-orange strip near the margin along which runs a series of black spots.

The underside of the forewing is dark brown with a reddish strip with black, white-centred eyespots near the outer edge.

The underside of the hindwing is brown, edged with a row of more or less distinct dark coloured eyespots.