Disclosed are harness assemblies for use in tethering a pet, such as a dog, to a leash. The harness assemblies distribute the forces associated with restraining the animal over the animal's entire body. The harness assemblies also provide a wide range of adjustability and are easy to position upon or take off the animal. Various buckle constructions are also disclosed for use in easily securing the harness onto an animal. The various components of the present invention, and the manner in which they interrelate, are described in greater detail hereinafter.