Emperor Shenzong of Song (25 May 1048 – 1 April 1085), 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 expanding Song territory and solving its fiscal, bureaucratic, and military problems through major reforms, but his reign remains controversial due to military failures and the varied effects of his changes.

Emperor Shenzong disagreed with the passive stance of his predecessors and wanted to improve the Song Dynasty's prestige via conquest. This irredentist attitude also contributed towards his desire to centralize fiscal matters: he told his war minister Wen Yanbo that "if we are to raise troops for our frontier campaigns, then our treasuries must be full." Furthermore, Shenzong was dissatisfied with the growing powers of ministers such as chief councillor Han Chi. Shenzong's goals were opposed by the conservatives, particularly Fu Bi and Sima Guang, who were concerned with his expansion of monarchical power and who wanted to maintain the peaceful equilibrium with the Western Xia and the Liao Dynasty. Shenzong respected the conservative faction: he kept Fu Bi in the capital until 1072 and had close relations with Sima Guang, whom he admired for his morality and intelligence.

Emperor Shenzong hired Muslim warriors from Bukhara to fight against the Khitan Liao dynasty. 5,300 Muslim men from Bukhara were encouraged and invited to move to China in 1070 by Shenzong to help battle the Liao empire in the northeast and repopulate areas ravaged by fighting. The emperor hired these men as mercenaries in his campaign against the Liao dynasty. Later on, these men were settled between the Song capital of Bianliang (today Kaifeng) and Yenching (modern Beijing). The circuits (道) of the north and northeast were settled in 1080 when 10,000 more Muslims were invited into China.

The minting of copper coins was the main form of money since the early Song dynasty. It peaked during Emperor Shenzong's reign, with 5.06 million guan minted in 1080, over six times more than 800,000 guan at the Northern Song's start. From 1074 to 1085, an average of 4.5 million guan were minted annually, dropping to 3 million under Emperor Huizong.

Agricultural tax collected in autumn and summer made up about a third of the state’s tax revenue over the ten year-Xining period. Most taxes, including a third of the agricultural tax, were paid in cash, showing a highly monetized financial structure. Industrial and commercial taxes contributed two thirds of the tax revenue.

During his reign in 1068, Emperor Shenzong became interested in Wang Anshi's policies and appointed Wang as the Chancellor. Wang implemented his famous New Policies aimed at improving the situation for the peasantry and unemployed. These acts became the hallmark reform of Emperor Shenzong's reign.

Before Shenzong took the throne in 1067, there was pressure on the Song dynasty to make economic reforms. The Song dynasty's rigorous civil service examinations rejuvenated humanist-oriented Confucian elite culture; in particular, the literati wanted to improve the material conditions of the people. Additionally, the humiliating loss against the Western Xia in the 1040s (as well as the unfavorable terms of the Treaty of Chanyuan) created, according to Sogabe Shizuo, a "perpetual wartime fiscal regime". Shenzong was particularly driven by his irredentist determination to recover the Sixteen Prefectures.

Immediately after taking the throne in 1067, Emperor Shenzong established the Office of Expenditure Reduction with Sima Guang at its head to improve Song finances. Sima refused and instead issued a scathing report discussing the immensity of the dynasty's financial problems. Indeed, defense consumed 83% of the dynasty's cash income, while the expanding and already-large bureaucracy was very costly to maintain. In 1069, after failing again to gain support for reform from the official Fu Bi, Shenzong made Wang Anshi the head of government and supported his consolidation of power and his New Policies.