Cheap flights from Oregon to Illinois from $136

The cheapest month to fly to Illinois from Oregon is in February. Flight prices, which tend to average around $302, are often lower during this time because this is during the off-season. If you aren’t able to travel to Illinois during the month of February, then flying in January is also cheap. Prices for this month can be found on momondo for an average of $311.

The cheapest day to depart from Oregon to Illinois is on a Wednesday when prices can be found for as low as $451. Flights from Oregon to Illinois on a Sunday will generally be more expensive and average around $557. Keep in mind that these prices on both days could fluctuate depending on the season and the demand.

Our most recent data shows that the best time of day to fly to Illinois is in the afternoon. Flights from Oregon to Illinois during this time can be as low as $366. Flights at noon are often more expensive with an average ticket price of $519.

Fly from Portland to Chicago Midway for the best Oregon - Illinois flight prices

You are more likely to see cheaper flights to Illinois from Oregon when booking weeks ahead of your departure date. In general, you can expect to find flights to Illinois for around $394 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Illinois from Oregon for as low as $309 on momondo.

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

Southwest, American Airlines, and Delta are the most popular carriers operating from Oregon to Illinois

United Airlines, American Airlines and Alaska Airlines are the top three most popular airlines that fly to Illinois from Oregon according to our data. United Airlines is the first choice among our users, with 46% of people opting to fly with this airline when traveling to Illinois. Keep in mind that there are 6 different airlines that fly to Illinois on a routine basis, so you have a few additional options to choose from.

The number of flights available between Oregon and Illinois is 24 per day as of October 2026. The most frequent departure time is 7:00AM, with 58% of daily flights leaving at noon.

The number of flights available between Oregon and Illinois is 168 per week as of October 2026. The most frequent departure day is Mon, with 18% of weekly flights leaving on this day.