Emperor Duanzong of Song (10 July 1269 – 8 May 1278), personal name Zhao Shi, was the 17th emperor of the Song dynasty of China and the eighth and penultimate emperor of the Southern Song dynasty. He was the fifth son of Emperor Duzong and an elder brother of his predecessor, Emperor Gong and successor Zhao Bing. The historical relic Sung Wong Toi in present-day Hong Kong's Kowloon City commemorates Zhao Shi's escape to Hong Kong.