The big dates that matter. Applications for Ontario universities open in mid-September on the OUAC (Ontario Universities' Application Centre) 101 system and close on the same January deadline each year. Inside that window, most universities assess candidates on the grades they're seeing at the time — which is why your first-semester and midterm marks matter more than you might think. September – October: Application opens. The OUAC 101 application opens in mid-September. You choose your programs, rank them, and pay the application fee. Most students look at program lists through October. Use this window to finalize your choices — you can add or adjust programs inside the application up to the deadline, subject to school-specific rules. November: Apply early, if you're ready. Applying in November (rather than waiting until January) lets your midterm grades be considered in the earliest assessment rounds. Ontario high schools report midterm grades in November, so a November application means universities have those updated marks. It doesn't guarantee an early offer, but it gets you into the right pile for your target program's timelines. December – January: Supporting evidence and deadlines. Many competitive programs require a supplementary application — the Waterloo AIF (Admissions Information Form), a written statement, an interview, or a portfolio. Those have their own deadlines, usually in late January or February, that can be earlier than the main OUAC deadline. The OUAC application itself closes in mid-January. Missing this year's date isn't recoverable — it's the one hard cutoff. February – May: Offer rounds. Offers go out in waves from late fall (limited) through the spring. The important thing to understand: offers are rolling and depend on the grades universities are seeing at each assessment. A late-semester improvement genuinely matters because many programs re-assess higher-level offers on updated marks. Final admission averages are calculated on the grades you have at the time of that program's last offer round. The best-6 reality. Most Ontario programs calculate your average on your top six Grade 12 U/M courses (your 'Best 6'). That means you don't need to be strong in every subject — you need your six best. Use the Grade Tracker here to project which six courses will carry you and where you still need to improve.