Cheap flights from South Dakota to Illinois from $101

The cheapest month to fly to Illinois from South Dakota is in November. Flight prices, which tend to average around $246, 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 November, then flying in January is also cheap. Prices for this month can be found on momondo for an average of $258.

The cheapest day to depart from South Dakota to Illinois is on a Wednesday when prices can be found for as low as $410. Flights from South Dakota to Illinois on a Monday will generally be more expensive and average around $664. 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 South Dakota to Illinois during this time can be as low as $377. Flights in the afternoon are often more expensive with an average ticket price of $495.

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

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

You could potentially save up to 5% on your flight if you consider stops on a South Dakota to Illinois flight.

As of August 2026, there are 22 flights per day flying from South Dakota to Illinois. The most common time of day flights depart is 12:00PM, with 51% of flights taking off in the afternoon.

The number of flights available between South Dakota and Illinois is 156 per week as of August 2026. The most frequent departure day is Mon, with 15% of weekly flights leaving on this day.