Search for cheap flights to Illinois, then tick the “No change fee” box under the “Flexible change policies” heading. From then on it’s smooth sailing. We understand that travel plans change and flexibility is essential, so book with confidence with Expedia.

Whether you’re travelling somewhere new or rendezvousing at a favourite haunt, these airlines are waiting to take you into or near Illinois:

• United Airlines - 13,063 flights to or near Illinois each month, including 12,950 flights to O’Hare Intl. Airport (ORD) and 108 flights to Quad City Intl. Airport (MLI) per month.
• American Airlines - 8,977 flights to or near Illinois each month, including 8,855 flights to O’Hare Intl. Airport (ORD) and 121 flights to Quad City Intl. Airport (MLI) per month.
• Southwest Airlines - 5,997 flights to or near Illinois each month, including 5,334 flights to Midway Intl. Airport (MDW) and 663 flights to O’Hare Intl. Airport (ORD) per month.

One of the easiest ways to find cheap tickets to Illinois is to be flexible with your travel dates. Search for your flights, then click “flexible dates” at the top of your results. It’ll reveal the cheapest prices for nearby days. The lowest price for a flight to Illinois in the last seven days was €357. Booking well in advance will generally help you score an even bigger bargain.

There were plenty of bargain fares up for grabs in the last seven days, with the cost of a return airfare to Illinois ranging between €357 and €587. Many lucky travellers nabbed one-way tickets from Shannon (SNN) for as little as €411.

Touch down at one of these top Illinois airports and you’ll be perfectly placed to discover all that this wonderful region has to offer:

• O’Hare Intl. Airport (ORD) - 25,318 flights per month.
• Midway Intl. Airport (MDW) - 5,962 flights per month.
• Quad City Intl. Airport (MLI) - 325 flights per month.

In the last seven days, plane fares to Illinois ranged from €357 to €587.

A terrific time to check out Chicago is after June 20 when the summer season starts. In Illinois’s main city, average temperatures range from 18ºC to 24ºC at this time — ideal weather for sightseeing! May, June and August are the most popular months to head to this hot spot.

The top month to purchase affordable flights to Illinois is February. Remember that in the U.S, an expensive time to reserve a ticket is during the busy month of December.