Ambassador Ryozo Kato was the Ambassador of Japan to the United States of America from September 2001 to July 2008, and is the longest-serving Japanese Ambassador to the U.S. after the War. Ambassador Kato joined the Ministry of Foreign Affairs in April 1965 and has held several positions in the Ministry such as Director of National Security Affairs Division in the North American Affairs Bureau, Director of Treaties Division in the Treaties Bureau, Deputy Director-General of the North American Affairs Bureau, Director-General of the Asian Affairs Bureau, Director-General of the Foreign Policy Bureau and Deputy Minister for Foreign Affairs.

As for overseas assignments, Ambassador Kato served in the U.S. four times, including his tenure as the Consul-General of Japan in San Francisco and the Ambassador in Washington, D.C. Ambassador Kato also served in Australia and in the Arab Republic of Egypt. Since June 2009, Ambassador Kato has been a Member of the Board of Mitsubishi Corporation. He served as Commissioner of Nippon Professional Baseball from 2008-2013. He is also Japan Chair of CULCON, the US-Japan Conference on Cultural and Educational Interchange. Ambassador Kato received a B.A. from the University of Tokyo and LL.M from Yale Law School.