Emperor Guangzong of Song (30 September 1147 – 17 September 1200), personal name Zhao Dun, was the 12th emperor of the Song dynasty in China and the third emperor of the Southern Song dynasty.
He was the third son of his predecessor, Emperor Xiaozong.
His mother was Emperor Xiaozong's first wife, Lady Guo (??; 1126–1156), who was posthumously honoured as "Empress Chengmu" (????).
His reign was relatively peaceful, but his lack of filial piety eventually made officials replace him with his son Emperor Ningzong.