Idia denticulalis, the toothed idia, is a litter moth of the family Erebidae.

The species was first described by Leon F. Harvey in 1875.

It is found in Quebec, Canada, and the US from Wisconsin to New England, south to Alabama and Texas.

Adults are on wing from April to September in Maryland and from July to August in Quebec.

Larvae feed on lichen and detritus, including dead leaves.