Koparion is a genus of small coelurosaurian theropod dinosaur, from the late Jurassic Period (Kimmeridgian stage), of Utah.

In 1993, Daniel Chure and Brooks Britt reported the discovery of small theropod remains, found by screenwashing large amounts of earth in the Rainbow Park near Dinosaur National Monument in Uintah County, Utah.

The specific name honors Earl Douglass, who, in the early twentieth century, excavated the Dinosaur National Monument quarry.

[2] The holotype specimen, DINO 3353, was found in the Brushy Basin Member of the Morrison Formation dating from the late Kimmeridgian, about 151 million years old.

[2] Within this context, Koparion could be used to refute the temporal paradox argument, that such a close relationship were unlikely because the then oldest known bird, Archaeopteryx, lived much earlier than the Deinonychosauria, i.e. the Troodontidae and the Dromaeosauridae;[4] later also non-fragmentary Jurassic troodontid material was reported, from China.