Oidaematophorus occidentalis is a moth of the family Pterophoridae.

It is found from Alberta and British Columbia to Arizona and Utah.

The forewings are the same colour as the thorax, normally with a heavy brown costal mark over the base of the cleft, preceded and followed by a few whitish scales.

This patch is connected with a small brown triangular shade before the cleft.

[4] The larvae feed on Aster, Grindelia[5] and Helianthus species.