Zhongshan Sanxin School International Department (ZSSID) is a private, residential secondary school located in the City of Zhongshan in Guangdong Province, China. Operating in its 11th year, ZSSID is an international school joint venture between Beijing’s Camford Education and Zhongshan’s Sanxin Education Group. The current enrollment is 200 students in grades 10–13, which is equivalent to grades 9–12 in the American high school system.

ZSSID is a College Board registered AP School (College Board CEEB Code 694630). In 2020, ZSSID received its certification from Cambridge Assessment International Education as a Cambridge International School (Center Code CX013). Admissions to ZSSID are select--ive, based on demonstrated achievements and personal character. Entrance placement tests in English and mathematics are required, followed by interviews with teachers from different academic disciplines.