Tsagantegia (/ˌsɑːɡɑːnˈteɪɡiə/; meaning Tsagan Teg) is a genus of medium-sized ankylosaurid thyreophoran dinosaur that lived in Asia during the Late Cretaceous period.

The holotype specimen, MPC 700/17, is a virtually complete skull that was recovered from the locality Tsagan-Teg (or "White Mountain") of the Bayan Shireh Formation in the southeastern Gobi Desert, Mongolia.

Unlike other Asian ankylosaurs, in Tsagantegia the caputegulae (cranial ornamentation) are not subdivided into a mosaic of polygons but are amorphous and flattened; they show some degree of symmetry.

[13] Additional to this, fossil fruits remains have been recovered from the Bor Guvé and Khara Khutul localities (Upper and Lower Bayan Shireh, respectively), suggesting the presence of Angiosperm plants.

[14] Tsagantegia shared its habitat with numerous animals from other localities of the formation, compromising dinosaur and non-dinosaur genera; such as the theropods Achillobator,[15] Alectrosaurus,[16] Erlikosaurus,[17] Garudimimus[18] and Segnosaurus;[17] the fellow ankylosaur Talarurus;[19] Marginocephalians: Amtocephale[20] and Graciliceratops;[21] the hadrosauroid Gobihadros,[7] and the large sauropod Erketu.