Shima is located on the southern half of Shima Peninsula in far eastern Mie Prefecture, facing Ise Bay of the Pacific Ocean. The city has two inlets: Matoya Bay and Ago Bay. Matoya Bay is famous for oyster cultivation and Ago Bay is famous for pearl cultivation. Both are sightseeing spots and most of the city is within the borders of the Ise-Shima National Park.
Shima has three inhabited islands; Watakano Island, Kashiko Island and Masaki Island. Watakano Island is located in Matoya Bay, and the others are in Ago Bay.