| Named By: | P. Godefroit, H. Demuynck, G. Dyke, D. Hu, F. O. Escuillie & P. Claeys in 2013 |
| Time Period: | Late Jurassic, 160 Ma |
| Location: | China, Liaoning Province - Tiaojishan Formation |
| Size: | About 30 centimetres long |
| Diet: | Insectivore/Carnivore |
| Fossil(s): | Almost complete individual |
| Classification: | | Chordata | Reptilia | Dinosauria | Saurischia | Theropoda | Deinonychosauria | Troodontidae | |
Eosinopteryx is an extinct genus of theropod dinosaurs known the late Jurassic period of China. It contains a single species, Eosinopteryx brevipenna.
E. brevipenna is known from a single fossil specimen recovered from the Tiaojishan Formation of western Liaoning Province, China, which has been dated to the late Jurassic period (Oxfordian age), about 160 million years ago. The name Eosinopteryx is derived from the Greek eos ("daybreak" or "dawn"), the Latin Sinae ("Chinese"), and the Greek pteryx ("feather"). The specific name brevipenna (from the Latin brevis, "short", and penna, "feather") refers to the reduced plumage preserved in the type specimen, YFGP-T5197.
Though initially classified as a troodontid, a more comprehensive analyses of its relationships have found it to be either a primitive paravian or an avialan.