How does KAYAK find such low prices on flights from Illinois to Denver?

KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Illinois to Denver. Visit our flight page for the latest deals!>/a>

How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Illinois to Denver?

KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Denver from Illinois is likely to change within 7 days, so travelers know whether to wait or book now. Visit our flight page for the latest deals!>/a>

What is the Hacker Fare option on flights from Illinois to Denver?

Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Denver with an airline and back to Illinois with another airline. Visit our flight page for the latest deals!>/a>

What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Illinois to Denver?

Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Denver from Illinois up to 3 days before/after your preferred dates. You can then pick the flights that suit you best. Visit our flight page for the latest deals!>/a>

$64 CHEAP FLIGHTS from Illinois to Denver

DEN

KAYAK searches hundreds of travel sites at once for deals on flights to Denver

...and more

Travelers love KAYAK

41,299,237 searches in the past 7 days on KAYAK

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Filter your dealsChoose cabin class, free Wi-Fi and more.

Cheapest round-trip

$76

Overall average: $168

Frontier

Wed 11/12Fri 11/14

STL - DEN • Non-stop

Cheapest one-way

$64

Typical prices: $93-$212

Frontier

Fri 10/24

STL - DEN • Non-stop

Start a new search

KAYAK searches 100s of sites at once to find you the best travel deals.

We hope you love your trip to Denver!

Flight Deals

Cheap Flights from Illinois to Denver

Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Illinois to Denver that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.

Discover the best prices for you by selecting your travel dates on KAYAK.

Round-trip

One-way

Last minute

Direct

Recent round-trip flight deals from Illinois to Denver

Wed, Nov 12 - Fri, Nov 14

7:45 pm - 9:13 pmSTL-DEN

2h 28mnonstop

6:00 am - 9:07 amDEN-STL

2h 07mnonstop

$76Frontier

Find Deal

Mon, Oct 27 - Tue, Oct 28

7:52 pm - 9:20 pmSTL-DEN

2h 28mnonstop

6:00 am - 9:07 amDEN-STL

2h 07mnonstop

$77Frontier

Find Deal

Fri, Dec 5 - Fri, Dec 12

3:08 pm - 4:34 pmPIA-DEN

2h 26mnonstop

5:24 pm - 8:21 pmDEN-PIA

1h 57mnonstop

$108Allegiant Air

Find Deal

Mon, Oct 27 - Fri, Oct 31

9:59 am - 11:15 amPIA-DEN

2h 16mnonstop

6:35 pm - 9:26 pmDEN-PIA

1h 51mnonstop

$113Allegiant Air

Find Deal

Wed, Nov 12 - Sat, Nov 15

9:22 pm - 12:19 pmORD-DEN

15h 57m2 stops

7:59 pm - 11:29 pmDEN-ORD

2h 30mnonstop

$130Multiple Airlines

Find Deal

Thu, Oct 23 - Tue, Oct 28

6:50 am - 8:31 amORD-DEN

2h 41mnonstop

12:59 am - 2:45 pmDEN-ORD

12h 46m2 stops

$142Multiple Airlines

Find Deal

Thu, Dec 11 - Sun, Dec 14

8:40 am - 10:32 amPIA-DEN

2h 52mnonstop

5:45 pm - 8:56 pmDEN-PIA

2h 11mnonstop

$209United Airlines

Find Deal

Thu, Nov 6 - Mon, Nov 10

8:52 am - 10:34 amMLI-DEN

2h 42mnonstop

5:47 pm - 9:01 pmDEN-MLI

2h 14mnonstop

$209United Airlines

Find Deal

Fri, Nov 7 - Mon, Nov 10

5:15 pm - 11:09 pmPIA-DEN

6h 54m1 stop

5:43 pm - 11:49 pmDEN-PIA

5h 06m1 stop

$229American Airlines

Find Deal

Thu, Nov 6 - Mon, Nov 10

5:56 am - 11:31 amMLI-DEN

6h 35m1 stop

5:43 pm - 11:21 pmDEN-MLI

4h 38m1 stop

$239American Airlines

Find Deal

Useful Info

Low season	April
High season	July
Cheapest flight	$64

Best time to beat the crowds but there is an average 4% increase in price.

Most popular time to fly with an average 3% increase in price.

Flight from St. Louis to Denver

How does KAYAK find such low prices on flights from Illinois to Denver?
KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Illinois to Denver.
How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Illinois to Denver?
KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Denver from Illinois is likely to change within 7 days, so travelers know whether to wait or book now.
What is the Hacker Fare option on flights from Illinois to Denver?
Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Denver with an airline and back to Illinois with another airline.
What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Illinois to Denver?
Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Denver from Illinois up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Dillon

Westminster

Lakewood

Broomfield

Englewood

Central City

Greenwood Village

Lone Tree

Wheat Ridge

Limon

Brighton

Fort Morgan

Evergreen

Erie

Everything you need to know for your flight to Denver

Airports

Cabin class

Complete your trip

Direct Flights

Flights to other cities

Origins

Other airports

Return flight deals

Information on the airport you'll fly into in Denver

Denver (DEN)

Not what you’re looking for? Find thousands of other hotels, flights, car rentals and package deals with KAYAK.

DEN

$64 Find Cheap Flights from Illinois to Denver

KAYAK searches hundreds of travel sites at once for deals on flights to Denver

Everything you should know

Cheap Flights from Illinois to Denver

Recent round-trip flight deals from Illinois to Denver

Recent one-way flight deals from Illinois to Denver

Recent last minute flight deals from Illinois to Denver

Recent direct flight deals from Illinois to Denver

Good to know

FAQs for booking flights from Illinois to Denver

How does KAYAK find such low prices on flights from Illinois to Denver?

KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Illinois to Denver.

How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Illinois to Denver?

KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Denver from Illinois is likely to change within 7 days, so travelers know whether to wait or book now.

What is the Hacker Fare option on flights from Illinois to Denver?

Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Denver with an airline and back to Illinois with another airline.

What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Illinois to Denver?

Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Denver from Illinois up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Traveling to a place near Denver?

Everything you need to know for your flight to Denver

Information on the airport you'll fly into in Denver

Cabin class types available on flights to Illinois

Complete your trip to Denver with a hotel stay or car rental

Find direct flights for Denver

Flights to other popular destinations

Flights from domestic origins to Denver

Choose which airport to fly into in Denver

Find deals for your return flight