Eupithecia repentina is a moth in the Geometridae family. It is endemic to eastern Russia, Korea, China and Japan. The species was introduced with its foodplant (Mosla dianthera) to a small park in Novomoskovsk (Tula Province, Russia) between 1950 and 1990. This small area now supports a small population of the species. The wingspan is about 19–21 mm. The ground colour of the forewings is mostly dark brown, but partly greyish. The hindwings are brownish yellow.