Emperor Gong of Song, personal name Zhao Xian, was the 16th emperor of the Song dynasty of China and the seventh emperor of the Southern Song dynasty. The sixth son of his predecessor, Emperor Duzong, Zhao Xian came to the throne around the age of four, and reigned for less than two years before he was forced to abdicate in 1276. He was succeeded by his fifth brother, Zhao Shi.

The Song dynasty was an imperial dynasty of China that ruled from 960 to 1279. The dynasty was founded by Emperor Taizu of Song, who usurped the throne of the Later Zhou dynasty and went on to conquer the rest of the Ten Kingdoms, ending the Five Dynasties and Ten Kingdoms period. The Song often came into conflict with the contemporaneous Liao, Western Xia and Jin dynasties in northern China. After retreating to southern China following attacks by the Jin dynasty, the Song was eventually conquered by the Mongol-led Yuan dynasty.