Ryōtsu (両津市, Ryōtsu-shi) was a city located in Sado Island, Niigata Prefecture, Japan.

As of 2003, the city had an estimated population of 16,710 and a density of 71.60 persons per km2.

On March 1, 2004, Ryōtsu, along with the rest of Sado Island (the towns of Aikawa, Kanai, Sawata, Hatano, Mano, Hamochi and Ogi, and the villages of Niibo and Akadomari (all from Sado District)), was merged to create the city of Sado.

Since then, Ryōtsu has been one of the 10 subdivisions of Sado City.

This Niigata Prefecture location article is a stub.