The State of Connecticut and Shandong Province established sister province/state relations in 1986. Stanford and Nanping City of Fujian (1993) and Jiangdu City of Jiangsu (2002), Bridgeport and Qingyuan City of Guangdong (1994), Westport and Yangzhou City of Jiangsu (1995), Trumbull and Xinyi City of Jiangsu (1996), Hartford and Dongguan City of Guangdong (2001), Torrington and Changzhou City of Jiangsu (2005) are sister cities.

In 2019, Connecticut's total trade in goods with China was US$3.24 billion, the same as 2018. Imports from China were US$1.98 billion, a year-on-year decrease of 13.9%; exports to China were US$1.26 billion, a year-on-year increase of 34.0%. China is Connecticut's fifth largest export market and third largest source of imports.