The generation and advancement of animal models have contributed significantly to the advancement of glaucoma research. This chapter describes and summarizes major nonprimate animal models useful for the study of this disease. Rodent models, both rats and mice, have been popular for glaucoma studies, because of the relatively better-developed genetic and genomic tools and the similarity of the relevant ocular structures between human and these animals. The larger animals, e.g., rabbit, feline, canine, bovine, ovine, and porcine models, have also been successfully used and provided valuable information on various aspects of the disease. Some of the models depicted in this chapter involve a transient or chronic ocular hypertension. Others do not affect intraocular pressure, but instead address certain specific mechanisms of the disease and serve as surrogate models.