St. Aloysius Gonzaga Secondary School, colloquially referred to as Zaga, is a Catholic high school located in the Erin Mills community of Mississauga, Ontario, named after Saint Aloysius Gonzaga. The school opened in Mississauga in 2001, after spending a year as a holding school in Georgetown. It is a joint venture between the city of Mississauga and the Dufferin-Peel Catholic District School Board. According to the Fraser Institute, it is currently ranked 2nd in the Dufferin-Peel Catholic District School Board behind, 6th in Mississauga, and 63rd out of 623 high schools in Ontario.