Sir Winston was founded in 1959, and named after the British Prime Minister, known mainly for his leadership of the United Kingdom during World War II.
Its campus contains a football/soccer/lacrosse field, a track, a parking lot, and a two-story building. The building includes a gymnasium with multiple changing rooms for boys and girls as well as showers, a weight room, and an auditorium. Construction has been underway in the school for a long time, and the result (unveiled in the 2011-2012 school year) is a brand new two-level cafeteria. The old cafeteria has been converted into a larger library, while the old library has been converted into two classrooms. Furthermore, there are now elevators available for the use of injured or handicapped students. The school's colours are navy blue and gold, and its mascot is the Bulldog.
The school is one of the most technology-based schools in the area, having classes such as Communications Technology (Com-Tech) and hosting a Specialist High Skills Major program in Film and Television Production. The school recently opened a new broadcast studio on the main floor, outfitted with studio lighting and high definition video cameras, that is used to broadcast the morning announcements - a student-run program called SWC NEWS.
Renovations over the summer of 2013 have given the school 6 new science labs and 4 new computer labs.
The school is also built on the same plans as another school in the city, Laura Secord Secondary School, located only 6.3 km away.