Clementi Town Secondary School (CTSS) is a government secondary school located in Clementi, Singapore, founded in the 1980s.
The school was officially opened on 22 July 1982 by the then-Member for Parliament of Clementi Bernard Chen. In 1984, in order to prevent students loitering in public places, the school's prefects, in cooperation with the Students' Care Service, set up a location for students to relax and study after school hours. This centre was the first of its kind in secondary schools in Singapore.