Orbital disease is common in dogs and cats. Clinical signs include exophthalmos, protrusion of the third eyelid, and resistance to retropulsion of the globe. This article discusses diagnostic work-up for dogs and cats with signs suggestive of orbital disease. Diagnosis and treatment of nonneoplastic orbital diseases follows. Congenital diseases are discussed first, followed by inflammatory diseases of the orbit including orbital pseudotumor. Lastly, other less common orbital conditions are addressed.