Cheap flights from Chicago to St. Louis from $49

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Chicago to St. Louis departing on 2/15. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
0 bags

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United Airlines Logo
9:10 pm - 10:43 pmORD-STL
1h 33mnonstop
United Airlines Logo
9:55 am - 11:30 amSTL-ORD
1h 35mnonstop
$138United Airlines
Find Deal
Wed, Dec 24 - Thu, Dec 25
Frontier Logo
12:07 pm - 2:46 pmORD-STL
26h 39m1 stop
Frontier Logo
8:22 pm - 2:02 pmSTL-ORD
17h 40m1 stop
$141Frontier
Find Deal
Fri, Jan 30 - Mon, Feb 2
Frontier Logo
8:27 pm - 7:50 amORD-STL
11h 23m1 stop
Frontier Logo
3:43 pm - 11:35 amSTL-ORD
19h 52m1 stop
$142Frontier
Find Deal
Thu, Jan 8 - Sun, Jan 11
Frontier Logo
10:07 pm - 10:02 amORD-STL
11h 55m1 stop
Frontier Logo
8:32 pm - 12:08 pmSTL-ORD
15h 36m1 stop
$146Frontier
Find Deal
Sun, Jan 11 - Wed, Jan 14
Delta Logo
5:59 pm - 10:16 pmMDW-STL
4h 17m1 stop
Delta Logo
6:05 am - 11:06 amSTL-MDW
5h 01m1 stop
$157Delta
Find Deal
Wed, Dec 24 - Thu, Dec 25
Delta Logo
4:01 pm - 10:16 pmORD-STL
6h 15m1 stop
Delta Logo
6:29 am - 12:54 pmSTL-ORD
6h 25m1 stop
$157Delta
Find Deal
Wed, Dec 24 - Thu, Dec 25
American Airlines Logo
10:35 pm - 11:56 pmORD-STL
1h 21mnonstop
American Airlines Logo
3:43 pm - 5:08 pmSTL-ORD
1h 25mnonstop
$168American Airlines
Find Deal
Thu, Nov 20 - Mon, Nov 24
American Airlines Logo
1:46 pm - 3:12 pmORD-STL
1h 26mnonstop
American Airlines Logo
6:00 am - 7:30 amSTL-ORD
1h 30mnonstop
$169American Airlines
Find Deal
Thu, Nov 20 - Mon, Nov 24
Southwest Logo
9:55 am - 11:15 amMDW-STL
1h 20mnonstop
Southwest Logo
5:55 pm - 7:05 pmSTL-MDW
1h 10mnonstop
$177Southwest
Find Deal
Sun, Jan 18 - Wed, Jan 21
Southwest Logo
9:55 am - 11:15 amMDW-STL
1h 20mnonstop
Southwest Logo
8:15 am - 1:20 pmSTL-MDW
5h 05m1 stop
$187Southwest
Find Deal
Sun, Jan 18 - Wed, Jan 21

Frontier flights from Chicago to St. Louis

Our best Frontier deals on Chicago to St. Louis flight tickets
Frontier
Jan 8
MDW6:10 amChicago Midway
8h 38m
1 stop
STL2:48 pmLambert-St Louis
Jan 11
STL9:35 amLambert-St Louis
13h 24m
1 stop
MDW10:59 pmChicago Midway
Frontier
Jan 30
ORD12:07 pmChicago O'Hare Intl
26h 39m
1 stop
STL2:46 pmLambert-St Louis
Feb 2
STL8:22 pmLambert-St Louis
17h 40m
1 stop
ORD2:02 pmChicago O'Hare Intl
Frontier
Jan 8
ORD8:27 pmChicago O'Hare Intl
11h 23m
1 stop
STL7:50 amLambert-St Louis
Jan 11
STL3:43 pmLambert-St Louis
19h 52m
1 stop
ORD11:35 amChicago O'Hare Intl

Delta flights from Chicago to St. Louis

Our best Delta deals on Chicago to St. Louis flight tickets
Delta
Dec 24
MDW5:59 pmChicago Midway
4h 17m
1 stop
STL10:16 pmLambert-St Louis
Dec 25
STL6:05 amLambert-St Louis
5h 01m
1 stop
MDW11:06 amChicago Midway
Delta
Nov 20
MDW10:47 amChicago Midway
5h 20m
1 stop
STL4:07 pmLambert-St Louis
Nov 24
STL7:05 amLambert-St Louis
4h 47m
1 stop
MDW11:52 amChicago Midway
Delta
Dec 31
ORD1:35 pmChicago O'Hare Intl
7h 06m
1 stop
STL8:41 pmLambert-St Louis
Jan 13
STL6:35 amLambert-St Louis
6h 33m
1 stop
ORD1:08 pmChicago O'Hare Intl

momondo Fare Finder

 
Customize your flight search to find flights from Chicago to St. Louis 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 November 17, 2025.
Use the filters below to find and compare flights from Chicago to St. Louis that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Wed 12/24

9:10 pm-10:43 pm

Nonstop1h 33m

Lambert-St Louis

Thu 12/25

9:55 am-11:30 am

Nonstop1h 35m

$138

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Fri 1/30

12:07 pm-2:46 pm

1 stop26h 39m

Lambert-St Louis

Mon 2/2

8:22 pm-2:02 pm

1 stop17h 40m

$141

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Thu 1/8

8:27 pm-7:50 am

1 stop11h 23m

Lambert-St Louis

Sun 1/11

3:43 pm-11:35 am

1 stop19h 52m

$142

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Sun 1/11

10:07 pm-10:02 am

1 stop11h 55m

Lambert-St Louis

Wed 1/14

8:32 pm-12:08 pm

1 stop15h 36m

$146

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

Wed 12/24

5:59 pm-10:16 pm

1 stop4h 17m

Lambert-St Louis

Thu 12/25

6:05 am-11:06 am

1 stop5h 01m

$157

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Wed 12/24

4:01 pm-10:16 pm

1 stop6h 15m

Lambert-St Louis

Thu 12/25

6:29 am-12:54 pm

1 stop6h 25m

$157

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Thu 11/20

10:35 pm-11:56 pm

Nonstop1h 21m

Lambert-St Louis

Mon 11/24

3:43 pm-5:08 pm

Nonstop1h 25m

$168

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Thu 11/20

1:46 pm-3:12 pm

Nonstop1h 26m

Lambert-St Louis

Mon 11/24

6:00 am-7:30 am

Nonstop1h 30m

$169

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

Sun 1/18

9:55 am-11:15 am

Nonstop1h 20m

Lambert-St Louis

Wed 1/21

5:55 pm-7:05 pm

Nonstop1h 10m

$177

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

Sun 1/18

9:55 am-11:15 am

Nonstop1h 20m

Lambert-St Louis

Wed 1/21

8:15 am-1:20 pm

1 stop5h 05m

$187

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to St. Louis from

How to get the cheapest flight ticket from Chicago to St. Louis

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 month to fly to St. Louis?

In general, August is the cheapest month to fly from Chicago to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $257. The month of April is another great option to travel to St. Louis, with average flight prices from Chicago averaging around $269.

What is the cheapest day to depart on your flight to St. Louis?

The cheapest day to depart on your flight to St. Louis is on a Thursday when prices can be found for as low as $308. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Monday because tickets tend to average around $510. These prices are subject to change though, so be sure to set up a Price Alert for flights to St. Louis.

What is the cheapest time of day to depart on your flight to St. Louis?

Flying to St. Louis from Chicago at noon is the least expensive time of day to depart. momondo users have found prices as low as $314 when looking at flights departing at noon. In the morning is when there is more demand to fly to St. Louis, so prices are often more expensive at around $432 per ticket.

What is the cheapest Chicago to Lambert-St Louis flight route?

Fly from Chicago O'Hare Intl to Lambert-St Louis for the best Chicago - Lambert-St Louis flight prices

How far in advance should I book a flight to St. Louis?

You are more likely to see cheaper flights to St. Louis from Chicago when booking weeks ahead of your departure date. In general, you can expect to find flights to St. Louis for around $294 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to St. Louis from Chicago for as low as $142 on momondo.

What cabin class options are available on Chicago to Lambert-St Louis flights?

There are 4 cabin classes available to choose from on Chicago to Lambert-St Louis flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Can stopping save me money on Chicago to St. Louis flights?

No. A direct flight is the cheapest option for a flight between Chicago to St. Louis.

How have Chicago to St. Louis flight prices changed over time?

As of November 2025, prices for Chicago to St. Louis flights are approximately 41% cheaper when compared to flights at the same time last year.

When to book flights from Chicago to St. Louis

Are you open to changing your travel dates? Check out the ideal times to fly from Chicago to St. Louis according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Chicago to St. Louis (CHI to STL) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Chicago to St. Louis

Best Price Found

$128

Fastest flight time

1h 10m

Direct flights

Every day

Airports in St. Louis

1 airport
The best one-way flight to St. Louis from Chicago in the past 72 hours is $128. The best round-trip flight deal from Chicago to St. Louis found on momondo in the last 72 hours is $227.
The fastest flight from Chicago to St. Louis takes 1h 10m
Direct flights go from Chicago to St. Louis every day.
There is 1 airport near St. Louis: Lambert-St Louis (STL)
  • How far is Chicago to Lambert-St Louis by plane?

    There are 262.0 mi between Chicago and Lambert-St Louis. Typically, this will take 1h 10m by plane in normal conditions.

  • When did momondo last update prices for flights from Chicago to Lambert-St Louis Airport?

    Prices for flights from Chicago to Lambert-St Louis Airport were last updated today.

  • How many operators does momondo search for flights from Chicago to Lambert-St Louis Airport?

  • How old do you have to be to fly from Chicago to Lambert-St Louis Airport?

    The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Chicago to Lambert-St Louis Airport.

  • What documentation or ID do you need to fly to Lambert-St Louis Airport?

    The travel and health documents required for your trip to Lambert-St Louis Airport can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Lambert-St Louis Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

  • What is the most popular plane model from Chicago to St. Louis?

  • What is the most popular airline from Chicago to St. Louis?

Best airlines flying from Chicago to St. Louis

Compare and see reviews for airlines that fly from Chicago to St. Louis with momondo
Airline
Rating
Free Cancellation
Price
SouthwestPriceFrom $77Free CancellationRating
8.0
4,245 reviews
Search Southwest flights
American AirlinesPriceFrom $115Free CancellationRating
7.2
11,048 reviews
Search American Airlines flights
Southern / MokulelePriceFrom $145Free CancellationRating
0.0
0 reviews
Search Southern / Mokulele flights
United AirlinesPriceFrom $152Free CancellationRating
7.4
9,014 reviews
Search United Airlines flights
  • Southwest Flights From Chicago to St. Louis

    Southwest operates around 28 flights from Chicago to St. Louis every week. The average price of these flights found in the last 72 hours has been $298, but momondo users have found Southwest deals from Chicago to St. Louis from as low as $77 round-trip. Southwest has been scored 8.0/10 in 4,245 reviews.

  • United Airlines Flights From Chicago to St. Louis

    Across 9,014 United Airlines reviews on momondo, the average score is 7.4/10. United Airlines flies from Chicago to St. Louis about 54 times each week, with ticket deals ranging from $152 to $306. Price data is based on momondo searches in the last 72 hours.

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
St. Charles
Chesterfield
Hermann
Fairview Heights
Florissant
Maryland Heights
O'Fallon
Wentzville
Fenton
Collinsville
St. Peters
Alton
Farmington
Festus
Glencoe
Edwardsville
Clayton
Eureka
Litchfield
Shrewsbury

Why use momondo?

Why should I use momondo to find a flight deal from Chicago to St. Louis?

To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to St. Louis from Chicago.

Can I find flights from Chicago to St. Louis with flexible booking policies on momondo?

Yes. momondo allows you to filter the results for Chicago to St. Louis flights to just show those with flexible booking policies.

How can momondo help me find flights from Chicago to St. Louis?

Once you have performed a search for Chicago to St. Louis flights, momondo helps you find the right one by offering useful filters to narrow down your flight selection. Flights can be filtered by multiple factors such as airline, airport and price; but also by other criteria like aircraft type and payment method.

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

Price alerts on flights to St. Louis from Chicago are quick and easy to set up on momondo. Simply perform a search and select the price alert feature. It is as simple as that.

An easier way to manage your St. Louis trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

Get notified when prices go down

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1 adult
Wed 12/17
Wed 12/24

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