SIR JOHN A MACDONALD CI is a secondary school (Gr9-Gr12)located in Scarborough, Ontario at 2300 Pharmacy Avenue. The school is named after the first prime minister of Canada. The school was opened in the fall of 1964 when there was only farmland around it, and as the population in the area grew, so did the school. The school's main building was then extended to have more classrooms, along with larger rooms used for music, art, and autoshop.

The school has an academic level named "Medallion" where exceptional students to have an enriching experience by having a more in-depth coverage of topics taught in regular classes.Students in the "Medallion" program are also taught topics that are not found in the curriculum, and are encouraged to write an academic competition related to their subject. Sir John A. Macdonald also has a reputation for its music program.As a public school, the music program gets insufficient funding, but with dedicated teachers, students, and parents, the many ensembles at this school raise funds through fundraisers, performances, and in the case for the jazz bands, gigs.

There are several clubs for science, math, computers, along with academic competitions and tests, like the University of Waterloo's mathematics (Pascal, Cayley, Fermat, and Euclid), chemistry (Avogadro and Chem 13), and physics (Sir Isaac Newton) exams,University of Toronto's engineering exam (DaVinci Engineering Competition), and several American ones as well.

Music ensembles include Intermediate Jazz band, Senior Jazz Band, Concert Band, Wind Ensemble, Strings, Symphony, and Choir, along with junior band and strings. Each year these groups compete in regional, provincial, and occasionally international competitions, and have trips internationally to perform.