Jiaxing lies in the northern Zhejiang province of the Yangtze River Delta of China. It is situated on the Grand Canal (Beijing-Hangzhou Canal) - the longest man-made canal in the world. It neighbors Hangzhou to the southwest, Huzhou to the west, Shanghai to the northeast and the Jiangsu province to the north. With a subtropical monsoon climate, it enjoys abundant rainfall and sunshine.

Jiaxing serves as the juncture of the Hangzhou-Shanghai Railway and Shanghai-Hangzhou Highway. The 320 State Highway runs across the city and has been designated as a station of the proposed Shanghai-Hangzhou Maglev Train Line. The city is within the 1.5 hour circle of three major international airports, namely Shanghai Pudong International Airport, Shanghai Hongqiao Airport and Hangzhou Xiaoshan International Airport.