Mamoru Shigemitsu (1887 - June 27, 1957) was the Japanese Minister of Foreign affairs at the end of World War II.

He, along with Yoshijiro Umezu, was the one who signed the instrument of surrender on September 2, 1945. He was later convicted of war crimes, and sentenced to 7 years imprisonment. He was paroled in 1950, and again served as Foreign minister (1954-1956)

Prior to that, he was

• Japan's ambassador to the Republic of China (1931-1932)
• Vice minister of foreign affairs (1933-1936)
• Ambassador to the Soviet Union 1936-1938
• Ambassador to the United Kingdom (1938-1941).