Ordosiodon is an extinct genus of therocephalian therapsids from the Early Triassic of China.

O. lincheyuensis, the type species, was named by Chinese paleontologist C. C. Young (Yang Zhongjian) in 1961 on the basis of a partial lower jaw.

[1] The jaw was discovered by a petroleum survey team in October 1958 from the Lower Ermaying Formation in Shanxi Province,[2] which dates back to the Olenekian stage.

[5] In 1979 a partial skull and skeleton was found from the same area as O. lincheyuensis and named Ordosia youngi in honor of Young.

The names Ordosia and Ordosiidae are now occupied by a genus and family of Cambrian trilobites.