Buginbaatar is an extinct genus of mammal from the Upper Cretaceous of Mongolia. It is a member of the extinct order Multituberculata, within the suborder Cimolodonta and family Cimolomyidae. It lived towards the end of the Mesozoic era. The genus Buginbaatar was named by Kielan-Jaworowska Z. and Sochava A.V. in 1969 based on the remains of a single species. Remains of this species, dubbed Buginbaatar clarki, were found in Upper Cretaceous strata of Bügiyn Tsav in Mongolia.