Tchoiria is a genus of simoedosaurid choristodere, a type of crocodile-like aquatic reptile. Fossils of this genus have been found in Early Cretaceous-age rocks in Mongolia. Four species have been named, but two have been given their own genera. The type species is T. namsari, based on PIN 3386/1, a partial skull and skeleton discovered in the Aptian-age Lower Cretaceous Hühteeg Formation at Hüren Dukh, central Mongolia. Two other species were named from this locality, with both later being reassigned: T. egloni, now Irenosaurus egloni; and T. magnus, now Ikechosaurus magnus. A fourth species, T. klauseni, was named from a partial skull and skeleton found in rocks of roughly the same age farther west in Mongolia.