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Cheap flights from Chicago to St. Louis from $46

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 9/16. 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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Find the cheapest flights from Chicago to St. Louis (CHI-STL)

Cheap round-trip flights

American Airlines Logo
7:10 pm - 8:32 pmORD-STL
1h 22mnonstop
American Airlines Logo
7:23 am - 8:45 amSTL-ORD
1h 22mnonstop
$91American Airlines
Find Deal
Tue, Sep 16 - Tue, Sep 23
American Airlines Logo
8:00 am - 9:26 amORD-STL
1h 26mnonstop
American Airlines Logo
7:16 am - 8:43 amSTL-ORD
1h 27mnonstop
$93American Airlines
Find Deal
Tue, Sep 30 - Tue, Oct 7
Southwest Logo
6:00 am - 11:30 amMDW-STL
5h 30m1 stop
Southwest Logo
1:20 pm - 5:05 pmSTL-MDW
3h 45m1 stop
$97Southwest
Find Deal
Tue, Sep 9 - Tue, Sep 9
Southwest Logo
7:30 am - 2:30 pmORD-STL
7h 00m1 stop
Southwest Logo
4:35 pm - 9:30 pmSTL-ORD
4h 55m1 stop
$97Southwest
Find Deal
Tue, Sep 16 - Tue, Sep 16
United Airlines Logo
12:55 pm - 2:19 pmORD-STL
1h 24mnonstop
United Airlines Logo
7:04 pm - 8:36 pmSTL-ORD
1h 32mnonstop
$136United Airlines
Find Deal
Thu, Sep 18 - Thu, Sep 18
United Airlines Logo
4:55 pm - 6:23 pmORD-STL
1h 28mnonstop
United Airlines Logo
7:04 pm - 8:36 pmSTL-ORD
1h 32mnonstop
$138United Airlines
Find Deal
Mon, Sep 15 - Mon, Sep 22
Frontier Logo
6:20 am - 3:04 pmMDW-STL
8h 44m1 stop
Frontier Logo
4:00 pm - 11:20 pmSTL-MDW
7h 20m1 stop
$144Frontier
Find Deal
Thu, Sep 4 - Sun, Sep 7
Frontier Logo
5:10 am - 3:04 pmORD-STL
9h 54m1 stop
Frontier Logo
4:00 pm - 12:10 amSTL-ORD
8h 10m1 stop
$144Frontier
Find Deal
Thu, Sep 4 - Sun, Sep 7
Southern / Mokulele Logo
10:34 pm - 11:48 pmORD-STL
1h 14mnonstop
Southern / Mokulele Logo
1:00 pm - 4:19 pmSTL-ORD
3h 19m1 stop
$149Southern / Mokulele
Find Deal
Thu, Sep 11 - Mon, Sep 15
Southern / Mokulele Logo
10:34 pm - 11:48 pmORD-STL
1h 14mnonstop
Southern / Mokulele Logo
1:00 pm - 4:19 pmSTL-ORD
3h 19m1 stop
$152Southern / Mokulele
Find Deal
Thu, Sep 11 - Mon, Sep 15

Southern / Mokulele flights from Chicago to St. Louis

Our best Southern / Mokulele deals on Chicago to St. Louis flight tickets
Southern / Mokulele
Sep 11
ORD10:34 pmChicago O'Hare Intl
1h 14m
STL11:48 pmLambert-St Louis
Sep 15
STL1:00 pmLambert-St Louis
3h 19m
1 stop
ORD4:19 pmChicago O'Hare Intl
$149
Find similar
Southern / Mokulele
Sep 11
ORD10:34 pmChicago O'Hare Intl
1h 14m
STL11:48 pmLambert-St Louis
Sep 15
STL1:00 pmLambert-St Louis
3h 19m
1 stop
ORD4:19 pmChicago O'Hare Intl
$152
Find similar
Southern / Mokulele
Oct 10
ORD1:10 pmChicago O'Hare Intl
3h 25m
1 stop
STL4:35 pmLambert-St Louis
Oct 12
STL5:15 pmLambert-St Louis
3h 24m
1 stop
ORD8:39 pmChicago O'Hare Intl
$169
Find similar

Southwest flights from Chicago to St. Louis

Our best Southwest deals on Chicago to St. Louis flight tickets
Southwest
Sep 9
MDW6:00 amChicago Midway
5h 30m
1 stop
STL11:30 amLambert-St Louis
Sep 9
STL1:20 pmLambert-St Louis
3h 45m
1 stop
MDW5:05 pmChicago Midway
$97
Find similar
Southwest
Sep 11
MDW11:45 amChicago Midway
1h 10m
STL12:55 pmLambert-St Louis
Sep 15
STL5:25 amLambert-St Louis
1h 10m
MDW6:35 amChicago Midway
$117
Find similar
Southwest
Sep 11
MDW7:45 amChicago Midway
5h 40m
1 stop
STL1:25 pmLambert-St Louis
Sep 15
STL7:20 pmLambert-St Louis
1h 05m
MDW8:25 pmChicago Midway
$127
Find similar

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 August 18, 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

Tue 9/16

7:10 pm-8:32 pm

Nonstop1h 22m

Lambert-St Louis

Tue 9/23

7:23 am-8:45 am

Nonstop1h 22m

$91

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Tue 9/30

8:00 am-9:26 am

Nonstop1h 26m

Lambert-St Louis

Tue 10/7

7:16 am-8:43 am

Nonstop1h 27m

$93

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

Tue 9/9

6:00 am-11:30 am

1 stop5h 30m

Lambert-St Louis

Tue 9/9

1:20 pm-5:05 pm

1 stop3h 45m

$97

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Tue 9/16

7:30 am-2:30 pm

1 stop7h 00m

Lambert-St Louis

Tue 9/16

4:35 pm-9:30 pm

1 stop4h 55m

$97

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Thu 9/18

12:55 pm-2:19 pm

Nonstop1h 24m

Lambert-St Louis

Thu 9/18

7:04 pm-8:36 pm

Nonstop1h 32m

$136

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Mon 9/15

4:55 pm-6:23 pm

Nonstop1h 28m

Lambert-St Louis

Mon 9/22

7:04 pm-8:36 pm

Nonstop1h 32m

$138

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

Thu 9/4

6:20 am-3:04 pm

1 stop8h 44m

Lambert-St Louis

Sun 9/7

4:00 pm-11:20 pm

1 stop7h 20m

$144

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Thu 9/4

5:10 am-3:04 pm

1 stop9h 54m

Lambert-St Louis

Sun 9/7

4:00 pm-12:10 am

1 stop8h 10m

$144

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Thu 9/11

10:34 pm-11:48 pm

Nonstop1h 14m

Lambert-St Louis

Mon 9/15

1:00 pm-4:19 pm

1 stop3h 19m

$149

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Thu 9/11

10:34 pm-11:48 pm

Nonstop1h 14m

Lambert-St Louis

Mon 9/15

1:00 pm-4:19 pm

1 stop3h 19m

$152

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 typical price of a round-trip flight between Chicago and St. Louis?

What is the cheapest month to fly to St. Louis?

In general, September 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 $263. The month of April is another great option to travel to St. Louis, with average flight prices from Chicago averaging around $268.

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 $319. 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 in the evening is the least expensive time of day to depart. momondo users have found prices as low as $287 when looking at flights departing in the evening. In the morning is when there is more demand to fly to St. Louis, so prices are often more expensive at around $429 per ticket.

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

Fly from Chicago Midway 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 $273 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 $118 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.

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

As of August 2025, prices for Chicago to St. Louis flights are approximately 49% 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

$46

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 $46. The best round-trip flight deal from Chicago to St. Louis found on momondo in the last 72 hours is $91.
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)
Search flight deals

  • Is flying the fastest way to get from Chicago to St. Louis?

    The quickest way to travel this route is to take a flight from Chicago to St. Louis, doing so can potentially save up to 4h 35m of travel time. While these options may take longer, booking a train from Chicago to St. Louis or a bus from Chicago to St. Louis may suit your needs if travel time is less of a factor in your decision making.

  • Is flying the cheapest way to get from Chicago to St. Louis?

    A train from Chicago to St. Louis is currently going to be the least expensive option currently available. You can also find deals for a flight from Chicago to St. Louis starting at $91, or consider a bus from Chicago to St. Louis starting at $68. Both of these alternative options are worth considering when looking to reach your destination.

  • 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
4,246 reviews
Search Southwest flights
American AirlinesPriceFrom $115Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights
Southern / MokulelePriceFrom $118Free CancellationRating
6.5
27 reviews
Search Southern / Mokulele flights
United AirlinesPriceFrom $152Free CancellationRating
7.4
8,925 reviews
Search United Airlines flights

  • Southwest Flights From Chicago to St. Louis

    Southwest operates around 22 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 4,246 reviews.

  • United Airlines Flights From Chicago to St. Louis

    Across 8,925 United Airlines reviews on momondo, the average score is 7.4/10. United Airlines flies from Chicago to St. Louis about 18 times each week, with ticket deals ranging from $152 to $325. 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
Fairview Heights
Hermann
Maryland Heights
Florissant
O'Fallon
Fenton
Wentzville
Collinsville
Alton
St. Peters
Farmington
Festus
Glencoe
Eureka
Clayton
Edwardsville
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.
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