Sumoto (洲本市, Sumoto-shi) is a city located on Awaji Island, Hyōgo Prefecture, Japan.

The Sumoto River flows into Osaka Bay in the center of the city area, part of which are within the borders of the Setonaikai National Park Hyogo Prefecture Sumoto has a humid subtropical climate (Köppen climate classification Cfa) with hot summers and cool winters.

Sumoto has a mayor-council form of government with a directly elected mayor and a unicameral city council of 18 members.

In terms of national politics, the city is part of Hyōgo 9th district of the lower house of the Diet of Japan.

Sumoto has traditionally been famous for its production of Awaji onions, Naruto oranges and Kobe Beef.