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Cheap flights from Casper to Illinois from $328

This is the cheapest round-trip flight price found by a momondo user in the last 72 hours by searching for a flight from Casper to Illinois departing on 1/31. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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0 bags

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Find the cheapest flights from Casper to Illinois

Cheap round-trip flights

Enter your travel dates to find the best prices.
United Airlines Logo
11:28 am - 8:58 pm
CPR
-
STL
8h 30m1 stop
United Airlines Logo
8:45 am - 4:54 pm
STL
-
CPR
9h 09m1 stop
$328United Airlines
Sat, Jan 31 - Tue, Feb 3
United Airlines Logo
3:17 pm - 8:58 pm
CPR
-
STL
4h 41m1 stop
United Airlines Logo
8:30 am - 8:40 pm
STL
-
CPR
13h 10m2 stops
$334United Airlines
Sat, Jan 31 - Tue, Feb 3
United Airlines Logo
1:16 pm - 11:59 pm
CPR
-
ORD
9h 43m1 stop
United Airlines Logo
12:53 pm - 7:06 pm
ORD
-
CPR
7h 13m1 stop
$338United Airlines
Fri, Jan 23 - Tue, Jan 27
United Airlines Logo
7:00 am - 4:03 pm
CPR
-
STL
8h 03m2 stops
United Airlines Logo
3:11 pm - 10:15 pm
STL
-
CPR
8h 04m2 stops
$339United Airlines
Sat, Jan 31 - Tue, Feb 3
United Airlines Logo
7:00 am - 1:20 pm
CPR
-
STL
5h 20m1 stop
United Airlines Logo
8:45 am - 4:54 pm
STL
-
CPR
9h 09m1 stop
$494United Airlines
Sat, Jan 3 - Wed, Jan 7
United Airlines Logo
7:00 am - 1:20 pm
CPR
-
STL
5h 20m1 stop
United Airlines Logo
6:30 am - 2:42 pm
STL
-
CPR
9h 12m2 stops
$499United Airlines
Sat, Jan 3 - Wed, Jan 7
United Airlines Logo
11:00 am - 9:46 am
CPR
-
ORD
21h 46m2 stops
United Airlines Logo
7:00 am - 10:53 am
ORD
-
CPR
4h 53m1 stop
$503United Airlines
Sat, Jan 3 - Wed, Jan 7
United Airlines Logo
11:26 am - 10:22 pm
CPR
-
STL
9h 56m1 stop
United Airlines Logo
6:00 pm - 10:14 pm
STL
-
CPR
5h 14m1 stop
$527United Airlines
Sun, Jan 4 - Fri, Jan 16
United Airlines Logo
1:22 pm - 10:22 pm
CPR
-
STL
8h 00m1 stop
United Airlines Logo
6:30 am - 4:54 pm
STL
-
CPR
11h 24m2 stops
$563United Airlines
Sun, Jan 4 - Fri, Jan 16
United Airlines Logo
11:00 am - 8:00 pm
CPR
-
ORD
8h 00m1 stop
United Airlines Logo
8:45 am - 4:54 pm
ORD
-
CPR
9h 09m1 stop
$578United Airlines
Sat, Jan 3 - Wed, Jan 7

United Airlines flights from Casper to Illinois

Our best United Airlines deals on Casper to Illinois flight tickets
United Airlines
Jan 31
CPR11:28 amCasper Natrona County
8h 30m
1 stop
STL8:58 pmLambert-St Louis
Feb 3
STL8:45 amLambert-St Louis
9h 09m
1 stop
CPR4:54 pmCasper Natrona County
$328
Find similar
United Airlines
Jan 31
CPR3:17 pmCasper Natrona County
4h 41m
1 stop
STL8:58 pmLambert-St Louis
Feb 3
STL8:05 amLambert-St Louis
9h 49m
2 stops
CPR4:54 pmCasper Natrona County
$334
Find similar
United Airlines
Jan 23
CPR1:16 pmCasper Natrona County
9h 43m
1 stop
ORD11:59 pmChicago O'Hare Intl
Jan 27
ORD12:53 pmChicago O'Hare Intl
7h 13m
1 stop
CPR7:06 pmCasper Natrona County
$338
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from Casper to Illinois that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 832,500 searches. Data last updated December 21, 2025.
Use the filters below to find and compare flights from Casper to Illinois that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

CasperSt. Louis

CPR - STL

CPRSTL

Casper Natrona County

Sat 1/31

11:28 am-8:58 pm

1 stop8h 30m

Lambert-St Louis

Tue 2/3

8:45 am-4:54 pm

1 stop9h 09m

$328

CasperSt. Louis

CPR - STL

CPRSTL

Casper Natrona County

Sat 1/31

3:17 pm-8:58 pm

1 stop4h 41m

Lambert-St Louis

Tue 2/3

8:30 am-8:40 pm

2 stops13h 10m

$334

CasperChicago

CPR - ORD

CPRORD

Casper Natrona County

Fri 1/23

1:16 pm-11:59 pm

1 stop9h 43m

Chicago O'Hare Intl

Tue 1/27

12:53 pm-7:06 pm

1 stop7h 13m

$338

CasperSt. Louis

CPR - STL

CPRSTL

Casper Natrona County

Sat 1/31

7:00 am-4:03 pm

2 stops8h 03m

Lambert-St Louis

Tue 2/3

3:11 pm-10:15 pm

2 stops8h 04m

$339

CasperSt. Louis

CPR - STL

CPRSTL

Casper Natrona County

Sat 1/3

7:00 am-1:20 pm

1 stop5h 20m

Lambert-St Louis

Wed 1/7

8:45 am-4:54 pm

1 stop9h 09m

$494

CasperSt. Louis

CPR - STL

CPRSTL

Casper Natrona County

Sat 1/3

7:00 am-1:20 pm

1 stop5h 20m

Lambert-St Louis

Wed 1/7

6:30 am-2:42 pm

2 stops9h 12m

$499

CasperChicago

CPR - ORD

CPRORD

Casper Natrona County

Sat 1/3

11:00 am-9:46 am

2 stops21h 46m

Chicago O'Hare Intl

Wed 1/7

7:00 am-10:53 am

1 stop4h 53m

$503

CasperSt. Louis

CPR - STL

CPRSTL

Casper Natrona County

Sun 1/4

11:26 am-10:22 pm

1 stop9h 56m

Lambert-St Louis

Fri 1/16

6:00 pm-10:14 pm

1 stop5h 14m

$527

CasperSt. Louis

CPR - STL

CPRSTL

Casper Natrona County

Sun 1/4

1:22 pm-10:22 pm

1 stop8h 00m

Lambert-St Louis

Fri 1/16

6:30 am-4:54 pm

2 stops11h 24m

$563

CasperChicago

CPR - ORD

CPRORD

Casper Natrona County

Sat 1/3

11:00 am-8:00 pm

1 stop8h 00m

Chicago O'Hare Intl

Wed 1/7

8:45 am-4:54 pm

1 stop9h 09m

$578

Flights are sorted by cheapest round-trip flights first.

Sorted by cheapest first

See travel insights to Illinois from

How to get the cheapest flight ticket from Casper to Illinois

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest day to depart on your flight to Illinois?

The cheapest day to depart from Casper to Illinois is on a Saturday when prices can be found for as low as $328. Flights from Casper to Illinois on a Friday will generally be more expensive and average around $485. Keep in mind that these prices on both days could fluctuate depending on the season and the demand.

What is the cheapest time of day to depart on your flight to Illinois?

Our most recent data shows that the best time of day to fly to Illinois is in the afternoon. Flights from Casper to Illinois during this time can be as low as $372. Flights at noon are often more expensive with an average ticket price of $375.

Can stopping save me money on Casper to Illinois flights?

You could potentially save up to 8% on your flight if you consider stops on a Casper to Illinois flight.

Cheap Casper to Illinois flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Casper to Illinois

Fastest flight time

5h 04m

Direct flights

None
The fastest flight from Casper to Illinois takes 5h 04m
There are no direct flights from Casper to Illinois. There are no popular flight routes from Casper to Illinois.
Search flight deals

  • When did momondo last update prices for flights from Casper Natrona County Airport to Illinois?

    Prices for flights from Casper Natrona County Airport to Illinois are updated daily.

  • How many operators does momondo search for flights from Casper Natrona County Airport to Illinois?

  • How old do you have to be to fly from Casper Natrona County Airport to Illinois?

    The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Casper Natrona County Airport to Illinois.

  • What documentation or ID do you need to fly to Illinois?

    The travel and health documents you'll need for your trip to Illinois may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Illinois. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

Why use momondo?

Why should I use momondo to find a flight deal from Casper to Illinois?

momondo collates all your flight options in one place and lets you filter them to find the perfect flight from Casper to Illinois. momondo saves you time and could save you money on your trip.

Can I find flights from Casper to Illinois with flexible booking policies on momondo?

Flights from Casper to Illinois with flexible booking policies can be found by using the search form above and then selecting our dedicated flexible booking filter, which will highlight only the flights where this policy is applied.

How can momondo help me find flights from Casper to Illinois?

momondo provides multiple filters to help you find the best flight to Illinois from Casper. Filter by price, airline, airports, cabin, aircraft, payment method, number of stops and more.

I’m not ready to book a flight from Casper to Illinois right now. Can momondo alert me if prices change?

Yes momondo offers price alerts on flights to Illinois from Casper. After performing a search on this page you should be able to see the price alert set up feature. Simply provide a valid email address and momondo will instantly alert you when prices change.

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