In 1929, the Council of the Township of York decided to construct a high school in memory of their youth killed in World War I. 9.5 acres were purchased for the school. Architect Charles Wellington Smith designed the building and the cornerstone was laid on May 6. The school was opened on September 3, 1929 to its first students. The Collegiate Gothic building with Don Valley Brick and smooth faded stone, consists of 15 classrooms, 3 science labs, an auditorium, cafeteria, two gyms, a swimming pool, and various offices. It was built at a cost of $250 000. The school officially opened on January 30, 1930. A World War II memorial was dedicated on February 27, 1949. Since the building was originally constructed in 1929, in 1954, an addition with six classrooms was added. This is followed by the construction of seven classrooms and library in 1961, followed by fourteen classrooms and pool area conversion in 1966. The next year, in 1967, a new swimming pool was built in the site of the Centennial building, with a gym and community centre. Eight rooms were converted between 1968 and 1969. The last addition, in the eastern portition, was built in 1971, currently houses the cafeteria, library, and the offices of the York school board. By 1973, fire escapes were added, space in the interior was converted for lockers. Some rooms were also converted in 1988. In 1985, the building was designated as a heritage building by the York City Council. On May 6 and 7, 2019, fires started in the YMCI building, which reached six-alarm status. The second fire caused sections of the roof and walls to collapse, as well as damage or destruction to the stained glass windows in the auditorium. All of the students were temporarily housed in nearby George Harvey Collegiate Institute. To accommodate the YMCI students for the 2019–20 school year, the TDSB selected the Scarlett Heights Entrepreneurial Academy on Royal York and Eglinton in Etobicoke, which closed its doors in 2018, as a temporary location for the school. The TTC began adjusting services on the 32 Eglinton West bus route as a result.
York Memorial has Roadmap to University with Success with Honours and Advanced Placement programs. The RUSH program is an enrichment program that trains students for the full AP program. AP courses are offered in a wide variety of subjects. There is also a Pre-Advanced Placement program which students attend in grades 10 to 11 before taking the AP program in grade 12.
Notable alumni
Samantha Bee – Comedian, The Daily Show correspondent
