Cheap flights from Oklahoma to Illinois from $29

The cheapest month to fly to Illinois from Oklahoma is in September. Flight prices, which tend to average around $264, 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 September, then flying in January is also cheap. Prices for this month can be found on momondo for an average of $322.

The cheapest day to depart from Oklahoma to Illinois is on a Thursday when prices can be found for as low as $528. Flights from Oklahoma to Illinois on a Monday will generally be more expensive and average around $748. 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 morning. Flights from Oklahoma to Illinois during this time can be as low as $522. Flights in the evening are often more expensive with an average ticket price of $909.

Fly from Tulsa to Chicago O'Hare Intl for the best Oklahoma - Illinois flight prices

You are more likely to see cheaper flights to Illinois from Oklahoma when booking weeks ahead of your departure date. In general, you can expect to find flights to Illinois for around $366 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Illinois from Oklahoma for as low as $244 on momondo.

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

Frontier, United Airlines, and Delta are the most popular carriers operating from Oklahoma to Illinois

American Airlines, United Airlines and Southwest are the top three most popular airlines that fly to Illinois from Oklahoma according to our data. American Airlines is the first choice among our users, with 52% of people opting to fly with this airline when traveling 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.

As of March 2026, there are 91 flights per day flying from Oklahoma to Illinois. The most common time of day flights depart is 10:00AM, with 50% of flights taking off at noon.

As of March 2026, there are 642 flights per week flying from Oklahoma to Illinois. The most common day of the week flights depart is Sat, with 27% of flights taking off on this day.