Zhejiang is one of the richest and most developed provinces in China. As of 2017, its nominal GDP was US$767 billion (CN￥ 5.18 trillion), about 6.26% of the country's GDP, and ranked 4th among province-level administrative units; the province's primary, secondary, and tertiary industries were worth CN￥201.70 billion (US$29.87 billion), CN￥2.2472 trillion (US$329.50 billion), and CN￥2.7279 trillion (US$404.03 billion) respectively. Its nominal GDP per capita was US$13,634 (CN￥92,057) and ranked the 5th in the country. The private sector in the province has been playing an increasingly important role in boosting the regional economy since Economic Reform in 1978.

Zhejiang's main manufacturing sectors are electromechanical industries, textiles, chemical industries, food, and construction materials. In recent years Zhejiang has followed its own development model, dubbed the "Zhejiang model", which is based on prioritizing and encouraging entrepreneurship, an emphasis on small businesses responsive to the whims of the market, large public investments into infrastructure, and the production of low-cost goods in bulk for both domestic consumption and export. As a result, Zhejiang has made itself one of the richest provinces, and the "Zhejiang spirit" has become something of a legend within China. However, some economists now worry that this model is not sustainable, in that it is inefficient and places unreasonable demands on raw materials and public utilities, and also a dead end, in that the myriad small businesses in Zhejiang producing cheap goods in bulk are unable to move to more sophisticated or technologically more advanced industries.  The economic heart of Zhejiang is moving from North Zhejiang, centered on Hangzhou, southeastward to the region centered on Wenzhou and Taizhou. The per capita disposable income of urbanites in Zhejiang reached 51,261 yuan (US$7,592) in 2017, an annual real growth of 8.5%. The per capita disposable income of rural residents stood at 24,956 yuan (US$3,696), the real growth of 9.2% year-on-year.

Traditionally, the province is known as the "Land of Fish and Rice". True to its name, rice is the main crop, followed by wheat; north Zhejiang is also a center of aquaculture in China, and the Zhoushan fishery is the largest fishery in the country. The main cash crops include jute and cotton, and the province also leads the provinces of China in tea production. (The renowned Longjing tea is a product of Hangzhou.) Zhejiang's towns have been known for handicraft production of goods such as silk, for which it is ranked second among the provinces. Its many market towns connect the cities with the countryside.

Ningbo, Wenzhou, Taizhou, and Zhoushan are important commercial ports. The Hangzhou Bay Bridge between Haiyan County and Cixi, is the longest bridge over a continuous body of seawater in the world.