Here, the semicircular canals of the most aquatic seal, the rare Antarctic Ross Seal (Ommatophoca rossii), are presented for the first time, along with representatives of every species in the Lobodontini: the leopard seal (Hydrurga leptonyx), Weddell seal (Leptonychotes weddellii), and crabeater seal (Lobodon carcinophagus). Because encounters with wild Ross seal are rare, and few specimens are available in collections worldwide, this dataset increases accessibility to a rare species. For further comparison, we present the bony labyrinths of other carnivorans, the elephant seal (Mirounga leonina), harbor seal (Phoca vitulina), walrus (Odobenus rosmarus), South American sea lion (Otaria byronia).