The Emperor Shenzong of Song, personal name Zhao Xu, was the sixth emperor of the Song dynasty of China. His original personal name was Zhao Zhongzhen but he changed it to "Zhao Xu" after he acceded to the throne. He reigned from 1067 until his death in 1085 and is best known for supporting Wang Anshi's New Policies. He was a particularly active monarch concerned with solving the fiscal, bureaucratic, and military problems of the Song dynasty, but his reign remains controversial.

Throughout Chinese history, "Emperor" was the superlative title held by the monarchs who ruled various imperial dynasties. In traditional Chinese political theory, the emperor was the "Son of Heaven", an autocrat with the divine mandate right to rule all under Heaven. Emperors were worshiped posthumously under an imperial cult. The lineage of emperors descended from a paternal family line constituted a dynasty, and succession in most cases theoretically followed agnatic primogeniture.