Xu Dunxin (Chinese: 徐敦信) (born December 10, 1934) is a Chinese diplomat.
He studied in Shanghai and at Peking University in Beijing.
He began work for the Ministry of Foreign Affairs of the People's Republic of China in 1964. he was posted in Tokyo from 1985 to 1988.
Between 1991 and 1993, he was stationed in Vietnam, Brunei, India and South Korea.
He was the 6th Ambassador of the People's Republic of China to Japan (1993–1998).