When Does School Start In Ontario 2025 Canada. Learn what you need to earn your ontario secondary school diploma (ossd) and graduate high school. View the greater essex county district school board's (gecdsb) school year calendars for elementary students and secondary students, including dates of statutory holidays, board designated holidays, professional activity.

Summer semester 2025 (12 week format) date September 3, 2025 first day of school for.