What is the cheapest airline that flies from Casper Natrona County to Illinois?

United Airlines is the most popular carrier operating from Casper Natrona County to Illinois

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?

There is 1 operator available for flights from Casper Natrona County Airport to Illinois as of February 2026.

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.

$328 Cheap Flights from Casper to Illinois in 2026

1 adult

0 bags

Save money when you book flights with momondo

Big names and deals

Search 100s of travel sites to compare prices.

Filter for what you want

Free Wi-Fi? Stopover? Instantly customize your results.

Trusted and free

We’re completely free to use - no hidden charges or fees.

Price Alerts

Not ready to book? to track prices.

Search flight deals

Find the cheapest flights from Casper to Illinois

Round-trip

One-way

Cheap round-trip flights

Enter your travel dates to find the best prices.

1:25 pm - 10:59 pm

CPR

STL

8h 34m

2 stops

5:55 pm - 9:59 pm

STL

CPR

5h 04m

1 stop

$374United Airlines

Wed, Mar 11 - Sun, Mar 15

5:55 pm - 12:30 am

CPR

ORD

5h 35m

1 stop

4:10 pm - 10:47 am

ORD

CPR

19h 37m

1 stop

$402United Airlines

Tue, Apr 7 - Fri, Apr 10

11:26 am - 4:49 pm

CPR

STL

4h 23m

1 stop

10:00 am - 5:02 pm

STL

CPR

8h 02m

2 stops

$437United Airlines

Wed, Mar 18 - Wed, Mar 25

5:25 am - 11:19 am

CPR

ORD

4h 54m

1 stop

7:00 am - 12:50 pm

ORD

CPR

6h 50m

1 stop

$444United Airlines

Wed, Mar 11 - Sun, Mar 15

1:25 pm - 11:34 pm

CPR

STL

9h 09m

1 stop

5:00 am - 2:40 pm

STL

CPR

10h 40m

2 stops

$489United Airlines

Tue, Mar 10 - Sat, Mar 14

1:25 pm - 10:59 pm

CPR

STL

8h 34m

2 stops

5:00 am - 2:40 pm

STL

CPR

10h 40m

2 stops

$494United Airlines

Tue, Mar 10 - Sat, Mar 14

1:25 pm - 8:00 pm

CPR

ORD

5h 35m

1 stop

9:48 pm - 5:02 pm

ORD

CPR

20h 14m

2 stops

$498United Airlines

Wed, Mar 11 - Sun, Mar 15

1:25 pm - 11:34 pm

CPR

STL

9h 09m

1 stop

9:00 am - 6:57 pm

STL

CPR

10h 57m

1 stop

$512United Airlines

Wed, Mar 18 - Wed, Mar 25

3:15 pm - 10:54 pm

CPR

ORD

6h 39m

1 stop

8:10 pm - 2:40 pm

ORD

CPR

19h 30m

2 stops

$513United Airlines

Mon, Mar 9 - Fri, Mar 13

1:25 pm - 8:41 pm

CPR

STL

6h 16m

1 stop

2:50 pm - 8:36 pm

STL

CPR

6h 46m

1 stop

$539United Airlines

Tue, Mar 10 - Sat, Mar 14

United Airlines flights from Casper to Illinois

Our best United Airlines deals on Casper to Illinois flight tickets

United Airlines

Mar 11

CPR1:25 pmCasper Natrona County

8h 34m

2 stops

STL10:59 pmLambert-St Louis

Mar 15

STL5:55 pmLambert-St Louis

5h 04m

1 stop

CPR9:59 pmCasper Natrona County

$374

United Airlines

Apr 7

CPR5:55 pmCasper Natrona County

5h 35m

1 stop

ORD12:30 amChicago O'Hare Intl

Apr 10

ORD4:10 pmChicago O'Hare Intl

19h 37m

1 stop

CPR10:47 amCasper Natrona County

$402

United Airlines

Mar 18

CPR11:26 amCasper Natrona County

4h 23m

1 stop

STL4:49 pmLambert-St Louis

Mar 25

STL10:00 amLambert-St Louis

8h 02m

2 stops

CPR5:02 pmCasper Natrona County

$437

Fly from

Fly to

Route

Depart

Return

Price

CasperSt. Louis

CPR - STL

CPRSTL

Casper Natrona County

Wed 3/11

1:25 pm-10:59 pm

2 stops8h 34m

Lambert-St Louis

Sun 3/15

5:55 pm-9:59 pm

1 stop5h 04m

$374

CasperChicago

CPR - ORD

CPRORD

Casper Natrona County

Tue 4/7

5:55 pm-12:30 am

1 stop5h 35m

Chicago O'Hare Intl

Fri 4/10

4:10 pm-10:47 am

1 stop19h 37m

$402

CasperSt. Louis

CPR - STL

CPRSTL

Casper Natrona County

Wed 3/18

11:26 am-4:49 pm

1 stop4h 23m

Lambert-St Louis

Wed 3/25

10:00 am-5:02 pm

2 stops8h 02m

$437

CasperChicago

CPR - ORD

CPRORD

Casper Natrona County

Wed 3/11

5:25 am-11:19 am

1 stop4h 54m

Chicago O'Hare Intl

Sun 3/15

7:00 am-12:50 pm

1 stop6h 50m

$444

CasperSt. Louis

CPR - STL

CPRSTL

Casper Natrona County

Tue 3/10

1:25 pm-11:34 pm

1 stop9h 09m

Lambert-St Louis

Sat 3/14

5:00 am-2:40 pm

2 stops10h 40m

$489

CasperSt. Louis

CPR - STL

CPRSTL

Casper Natrona County

Tue 3/10

1:25 pm-10:59 pm

2 stops8h 34m

Lambert-St Louis

Sat 3/14

5:00 am-2:40 pm

2 stops10h 40m

$494

CasperChicago

CPR - ORD

CPRORD

Casper Natrona County

Wed 3/11

1:25 pm-8:00 pm

1 stop5h 35m

Chicago O'Hare Intl

Sun 3/15

9:48 pm-5:02 pm

2 stops20h 14m

$498

CasperSt. Louis

CPR - STL

CPRSTL

Casper Natrona County

Wed 3/18

1:25 pm-11:34 pm

1 stop9h 09m

Lambert-St Louis

Wed 3/25

9:00 am-6:57 pm

1 stop10h 57m

$512

CasperChicago

CPR - ORD

CPRORD

Casper Natrona County

Mon 3/9

3:15 pm-10:54 pm

1 stop6h 39m

Chicago O'Hare Intl

Fri 3/13

8:10 pm-2:40 pm

2 stops19h 30m

$513

CasperSt. Louis

CPR - STL

CPRSTL

Casper Natrona County

Tue 3/10

1:25 pm-8:41 pm

1 stop6h 16m

Lambert-St Louis

Sat 3/14

2:50 pm-8:36 pm

1 stop6h 46m

$539

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 12 resultsSorted by cheapest first

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

Prices

Airlines

Can stopping save me money on Casper to Illinois flights?

You could potentially save up to 35% 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	4h 23m
Direct flights	None

The fastest flight from Casper to Illinois takes 4h 23m

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?
There is 1 operator available for flights from Casper Natrona County Airport to Illinois as of February 2026.
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.