Sister-state agreements establish relations of cooperation and friendship by promoting a wide range of academic, cultural, economic and technological exchanges between states. The State of Ohio has entered into the following sister-state relationships:
- State of Ohio and Hubei Province, The People's Republic of China, signed in October 1979. Renewed by Governor Ted Strckland and Yang Song, Deputy Party Secretary of CPC Hubei Provincial Committee, Party Secretary of CPC Wuhan Municipal Committee in October 2009.
- State of Ohio and Anambra State, The Federal Republic of Nigeria signed by Governor James Rhodes and Governor Nwobodo of Anambra in October 1979.
- State of Ohio and the Province of Taiwan, signed in June 1985.
- State of Ohio and State of Parana, Brazil, signed by Governor Richard Celeste and Governor Richa in May 1986. Renewed by Governor George Voinovich and Governor Lerner in March 1998.
- State of Ohio and State of Lower Austria, signed by Governor Richard Celeste and Honorable Siegfried Ludvig in June 1989.
- State of Ohio and Saitama Prefecture, Japan, signed by Governor Richard Celeste and Governor Hata, in May 1990.
- State of Ohio and Kyongsangbuk-do, The Republic of Korea, signed in December 1984. Renewed by Governor George Voinovich and Governor Lee in March 1997 and Governor Bob Taft and Governor Lee on October 2000.