Cheap flights from Montreal Pierre Elliott Trudeau Intl Airport to Illinois from C$ 226

In general, April is the cheapest month to fly from Montreal Pierre Elliott Trudeau Intl Airport to Illinois. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around C$ 381. If you don’t want to visit Illinois in April, then you should wait until February to fly from Montreal Pierre Elliott Trudeau Intl Airport, when ticket prices are also cheap, with an average price of C$ 398.

According to our data, Thursday is the cheapest day to fly to Illinois from Montreal Pierre Elliott Trudeau Intl Airport. The lowest ticket price found for a Thursday departure recently was C$ 696. Keep in mind that prices can always vary depending on your route and whether or not you are flying domestic or international. The most expensive day to fly to Illinois is Sunday, with ticket prices averaging around C$ 996.

Our most recent data shows that the best time of day to fly to Illinois is in the afternoon. Flights from Montreal Pierre Elliott Trudeau Intl Airport to Illinois during this time can be as low as C$ 749. If you have a flexible travel schedule, then try to avoid flying at noon when prices are C$ 1,104 on average. Flights to Illinois from Montreal Pierre Elliott Trudeau Intl Airport at noon are generally more expensive because this time of day is more convenient for travellers’ schedules.

Fly from Montreal Pierre Elliott Trudeau Intl to Chicago O'Hare Intl for the best Montreal Pierre Elliott Trudeau Intl - Illinois flight prices

You are more likely to see cheaper flights to Illinois from Montreal Pierre Elliott Trudeau Intl Airport when booking weeks ahead of your departure date. In general, you can expect to find flights to Illinois for around C$ 499 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Illinois from Montreal Pierre Elliott Trudeau Intl Airport for as low as C$ 318 on momondo.

There are 4 cabin classes available to choose from on Montreal Pierre Elliott Trudeau Intl Airport to Illinois flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Porter Airlines, Delta, and United Airlines are the most popular carriers operating from Montreal Pierre Elliott Trudeau Intl to Illinois

Air Canada, United Airlines and Porter Airlines are the top three most popular airlines that fly to Illinois from Montreal Pierre Elliott Trudeau Intl Airport according to our data. Air Canada is the first choice among our users, with 72% of people opting to fly with this airline when travelling to Illinois. Keep in mind that there are 4 different airlines that fly to Illinois on a routine basis, so you have a few additional options to choose from.

29 flights are operational daily from Montreal Pierre Elliott Trudeau Intl Airport to Illinois as of August 2026. The most popular departure time for this route is 6:00a.m., with 52% of flights per day taking off in the afternoon.

The number of flights available between Montreal Pierre Elliott Trudeau Intl Airport and Illinois is 207 per week as of August 2026. The most frequent departure day is Mon, with 16% of weekly flights leaving on this day.