Cheap flights from Sioux Falls to Illinois from $98

The cheapest month to fly to Illinois from Sioux Falls is in April. Flight prices, which tend to average around $151, 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 April, then flying in September is also cheap. Prices for this month can be found on momondo for an average of $154.

The cheapest day to depart from Sioux Falls to Illinois is on a Friday when prices can be found for as low as $399. Flights from Sioux Falls to Illinois on a Monday will generally be more expensive and average around $642. 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 evening. Flights from Sioux Falls to Illinois during this time can be as low as $389. Flights in the afternoon are often more expensive with an average ticket price of $488.

Fly from Sioux Falls Joe Foss Field to Chicago O'Hare Intl for the best Sioux Falls Joe Foss Field - Illinois flight prices

You are more likely to see cheaper flights to Illinois from Sioux Falls when booking weeks ahead of your departure date. In general, you can expect to find flights to Illinois for around $301 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Illinois from Sioux Falls for as low as $195 on momondo.

The number of flights available between Sioux Falls and Illinois is 18 per day as of May 2026. The most frequent departure time is 3:00PM, with 44% of daily flights leaving in the afternoon.

As of May 2026, 129 flights take off from Sioux Falls and land in Illinois each week. The most common flight departure day for this route is Fri, with 16% of weekly flights taking off on this day.