Arginbaatar is a genus of extinct mammal from the Lower Cretaceous of Mongolia. It was a member of the Multituberculata, an order which is also extinct. It belongs to the family Arginbaataridae (Hahn & Hahn 1983). The genus Arginbaatar was named by Trofimov B.A. in 1980. Baatar is Mongolian for "hero" or "warrior."The primary species, Arginbaatar dmitrievae, was also named by Trofimov.