Pseudopostega rotunda is a moth of the family Opostegidae. It is found known from the lowland forest of the La Selva Biological Reserve in north-eastern Costa Rica, the Guanacaste Province in north-western Costa Rica and the Napo Province in east-central Ecuador.
The length of the forewings is 1.9–2.1 mm. Adults are on wing from mid-February to mid-June in Costa Rica and in January in Ecuador.