Hanssuesia is a genus of pachycephalosaurid dinosaurs from the late Cretaceous period. It lived in what is now Alberta and Montana, and contains the single species Hanssuesia sternbergi. Hanssuesia is based on a skull dome originally named Troodon sternbergi by Barnum Brown and Erich Maren Schlaikjer in 1943. The specific name honoured Charles Mortram Sternberg who found the dome in 1928 near Steveville in south Alberta. In 1945, it was transferred to Stegoceras by C.M. Sternberg himself, as a Stegoceras sternbergi.