ʻO ka Leonberger he'īlio nui loa, nani e hui pū i ka mana nui a me ka hanohano. ʻO ke ʻano maoli o ka liona ke kapa o ke kūlanakauhale ʻo Leonberg, kahi i hānai ʻia ai ka pua. ʻO ke kiʻekiʻe kiʻekiʻe o nā ʻīlio ma ka maloʻo he 80 cm.
He nui ka nui o Leonberger. ʻOi aku ka nui o ka ʻīlio S ma mua o ia, ma muli o ke kapa lalo i hoʻomohala ʻia. Me kēia ʻano, he malihini loa ka clumsiness a me ka stockiness. ʻO nā ʻīlio Leonberger nā ʻīlio like ʻole, kūlike, nona ka wai a me ka nani. He kumukānāwai ikaika ko nā ʻīlio, nā ʻiʻo i ulu maikaʻi ʻia, ka umauma ākea, a me nā lālā ikaika loa. ʻO ke poʻo he voluminous, me ka hoʻololi mālie mai ka lae a hiki i ke kai, hoʻokiʻekiʻe ka'īlio i kona poʻo; ʻano lōʻihi ka waha, ʻaʻole kuhikuhi. Paʻa nā lehelehe, ikaika loa nā ʻauwae, nunui a ikaika nā niho, ʻokiʻoki ka nahu. He waena ka nui o nā maka, oval, māmā a ʻeleʻele ʻeleʻele. Kulou nā pepeiao, kokoke i ke poʻo, pōʻai ma ka piko. Hoʻonohonoho ʻia ka huelo haʻahaʻa, lōʻihi a ikaika. I ka hoʻomaha ʻana, hoʻohaʻahaʻa ʻia i lalo, ma kahi kūlana ikaika e kūlou iki i luna, akā ʻaʻole piʻi ma luna o ke kiʻekiʻe o ke kua.