Struthiomimus ("ostrich mimic", the name derived from Greek "strutheios" meaning 'of the ostrich' and "mimos" meaning 'imitator') is a genus of omnivorous bird-like dinosaurs, bearing a superficial resemblance to modern ostriches, that lived in the late Cretaceous period, 80 - 66 million years ago.
Struthiomimus was 4.3 m long and 1.4 m high at the hip. Its skull was small, with large eyes, above a relatively long and slender neck. It had a toothless beak. The forelimbs ('arms') were also long and slender, albeit with mighty claws, whereas the hind limbs were long and powerful, with short strong toes terminating in hoof-like claws. They were fast runners, probably the fastest of all dinosaurs, as the speed was apparently their only defense against predators. They are estimated to have been able to run at speeds between 50 and 80 km/h.
Struthiomimus fossils have been found in Asia and North America.