Waterloo Collegiate Institute (WCI) is a secondary school in Waterloo, Ontario, Canada. The school is run by the Waterloo Region District School Board. During the 2019–2020 school year, 1,475 students were enrolled at the school. It has magnet programs including English as a Second Language (E.S.L.), Extended French, Geography and Strings instruments. On June 4, 2010, the school celebrated its 50th anniversary.