Eupithecia pygmaeata, the marsh pug, is a moth of the family Geometridae.

It is known from most of Europe, western and southern Siberia, the Russian Far East, northern Mongolia and North America (from Alaska to Newfoundland and Labrador and Quebec, south to Colorado).The species primarily colonizes floodplain and disused forests, bogs, river banks and marshy meadows.

The forewings have a small white dot at the inner angle and two dark spots at the costal edge.

The hindwings are similar in colour and have a pale dot at the tornal margin.

The cremaster is equipped with a total of eight hook bristles, the middle pair of which is more powerfully formed.