HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
St. Louis

$69+ Cheap flights from Illinois to St. Louis (STL)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 2/17. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — STL
Jan 11 — Jan 181
Sun 1/11
Sun 1/18
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Illinois to St. Louis with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheap flight deals from Illinois to St. Louis

Cheapest flights from Illinois to St. Louis
Explore the most affordable flight options available from Illinois to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on December 12, 2025.

This American Airlines deal was found by Cheapflights users on 12/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/317:14 amORD - STL
Nonstop1h 34mAmerican Airlines
Tue 1/136:00 amSTL - ORD
Nonstop1h 27mAmerican Airlines
Deal found 12/11$170
This Frontier deal was found by Cheapflights users on 12/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/3111:23 amORD - STL
1 stop11h 10mFrontier
Thu 1/110:42 amSTL - ORD
1 stop11h 42mFrontier
Deal found 12/9$188
This Southwest deal was found by Cheapflights users on 12/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/248:25 amMDW - STL
Nonstop1h 15mSouthwest
Thu 12/254:25 pmSTL - MDW
Nonstop1h 10mSouthwest
Deal found 12/9$215
This United Airlines deal was found by Cheapflights users on 12/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/249:10 pmORD - STL
Nonstop1h 33mUnited Airlines
Thu 12/256:35 pmSTL - ORD
Nonstop1h 44mUnited Airlines
Deal found 12/9$215
This Delta deal was found by Cheapflights users on 12/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/316:35 amORD - STL
1 stop4h 37mDelta
Tue 1/136:00 amSTL - ORD
1 stop7h 40mDelta
Deal found 12/10$228
This eDestinos deal was found by Cheapflights users on 12/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure eDestinos is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/316:05 amORD - STL
1 stop27h 35mFrontier
Tue 1/135:11 pmSTL - ORD
2 stops18h 57mFrontier
Deal found 12/10$230
This American Airlines deal was found by Cheapflights users on 12/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/2412:45 pmORD - STL
Nonstop1h 24mAmerican Airlines
Thu 12/259:08 amSTL - ORD
Nonstop1h 27mAmerican Airlines
Deal found 12/11$247
This Kiwi.com deal was found by Cheapflights users on 12/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/316:05 amORD - STL
2 stops16h 28mMultiple Airlines
Tue 1/135:11 pmSTL - ORD
1 stop20h 02mMultiple Airlines
Deal found 12/11$254
This Southwest deal was found by Cheapflights users on 12/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/2411:25 amMDW - STL
Nonstop1h 10mSouthwest
Fri 12/262:15 pmSTL - MDW
Nonstop1h 05mSouthwest
Deal found 12/9$317
This Southwest deal was found by Cheapflights users on 12/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/255:15 pmMDW - STL
Nonstop1h 15mSouthwest
Sun 12/283:05 pmSTL - MDW
1 stop6h 20mSouthwest
Deal found 12/11$340
This Kiwi.com deal was found by Cheapflights users on 12/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/246:12 amMDW - STL
2 stops16h 21mFrontier
Thu 12/2510:42 amSTL - MDW
1 stop11h 30mFrontier
Deal found 12/9$348
This Southwest deal was found by Cheapflights users on 12/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/259:50 amMDW - STL
1 stop3h 10mSouthwest
Mon 12/294:40 pmSTL - MDW
1 stop4h 45mSouthwest
Deal found 12/11$367

Find flight deals from Illinois to St. Louis

Keep the following information in mind while searching for Illinois to St. Louis flight deals. Data was last updated December 12, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$117
(American Airlines)

One-way from

$69
(Southwest)

Popular in

October

Cheapest in

November

Average price

$257

Good round-trip deal

$61 or less

Good one-way deal

$98 or less
Provider with most accurate pricing for Chicago (CHI)-Lambert-St Louis flight deals.
Search Deals
Provider most trusted by Cheapflights users for Chicago (CHI)-Lambert-St Louis flights.
Search Deals
From Illinois to Lambert-St Louis
Search Deals
One-way flight from Illinois to Lambert-St Louis
Search Deals
Highest demand for flights based on searches. 2% potential increase in price ($8 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($8 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in December 2025
Search Deals
Price to beat on a round-trip flight from Illinois to Lambert-St Louis.
Search Deals
Price to beat on a one-way flight from Illinois to Lambert-St Louis.
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Illinois 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, Cheapflights users made 2,558,603 searches. Data last updated December 12, 2025.
Use the filters below to find and compare flights from Illinois to St. Louis that are best for you.

Fly from

Illinois

Fly to

St. Louis

Route

Depart

Return

Price

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

Mon 2/23

5:50 am-7:10 am

Nonstop1h 20m

Lambert-St Louis

Tue 2/24

6:05 am-7:15 am

Nonstop1h 10m

$144

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

Tue 1/20

9:50 am-2:38 pm

1 stop4h 48m

Lambert-St Louis

Tue 1/27

7:10 am-11:59 am

1 stop4h 49m

$157

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Wed 1/7

1:55 pm-8:43 pm

1 stop6h 48m

Lambert-St Louis

Wed 1/14

6:35 am-1:08 pm

1 stop6h 33m

$157

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

Thu 1/8

6:10 am-2:48 pm

1 stop8h 38m

Lambert-St Louis

Mon 1/12

8:50 am-11:09 pm

1 stop14h 19m

$162

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Thu 1/8

4:49 pm-7:50 am

2 stops15h 01m

Lambert-St Louis

Mon 1/12

5:11 pm-1:13 pm

1 stop20h 02m

$162

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

Wed 1/7

9:32 am-4:45 pm

2 stops7h 13m

Lambert-St Louis

Wed 1/14

6:10 am-1:09 pm

1 stop6h 59m

$162

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Mon 2/23

1:45 pm-8:00 pm

2 stops6h 15m

Lambert-St Louis

Tue 2/24

6:20 am-1:00 pm

1 stop6h 40m

$169

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

Thu 1/8

9:55 am-11:15 am

Nonstop1h 20m

Lambert-St Louis

Mon 1/12

5:55 pm-7:05 pm

Nonstop1h 10m

$171

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

Thu 2/19

5:50 am-7:10 am

Nonstop1h 20m

Lambert-St Louis

Sat 2/21

6:10 am-7:20 am

Nonstop1h 10m

$171

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

Sat 1/17

6:40 am-8:05 am

Nonstop1h 25m

Lambert-St Louis

Sat 1/17

10:25 am-11:35 am

Nonstop1h 10m

$171

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/10

Showing 1-10 of 39 results
1
2
3
4

Best time to book a flight from Illinois to St. Louis

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Illinois with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Illinois to St. Louis

What is the cheapest month to book a flight from Illinois to St. Louis?

Currently, August is the cheapest month in which you can book a flight from Illinois to St. Louis (average of $77). Flying from Illinois to St. Louis in July is currently the most expensive (average of $172). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from IL to STL?

Find hourly flight availability from Illinois to St. Louis. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated December 12, 2025.

It’s typically best to fly out from Illinois to St. Louis in the evening. Doing so could potentially save you 34% on the flight price compared to flying in the afternoon, which is usually more expensive.

What is the cheapest day to fly from Illinois to St. Louis?

Use this chart to determine the cheapest time to fly round-trip from Illinois to St. Louis. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Illinois to St. Louis flight should consider departing on Wednesday evenings when fares are most often at their lowest. Sunday afternoons flights should be avoided if possible as fares are typically the most expensive at this time.

Weekly flight availability from Illinois to St. Louis

Explore weekly flight availability from Illinois to St. Louis. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated December 12, 2025.

The most flights from USIL to STL are scheduled on a Thursday (62 on average). You will have fewer flight options on Friday, which is when the least amount of flights are scheduled (47 on average).

Related info for your journey

Find useful and relevant information for your journey from Illinois to St. Louis. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly into for flights to St. Louis from Illinois?

    If you book a flight to St. Louis from Illinois, you will be flying to Lambert-St Louis, which is the city’s only airport. Lambert-St Louis (STL) is located 12.7 mi from the center of St. Louis.

  • How long is the flight from Illinois to St. Louis?

    Airlines like Southwest, Delta, and American Airlines fly from Illinois to St. Louis in about 1h 20m. The time it takes to get you to your destination can typically vary by up to 3h 28m. There are 251 mi between Illinois and St. Louis. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the cheapest airlines to fly from Illinois to St. Louis one-way?

    The cheapest airline one-way is Southern / Mokulele, with whom users have recently found tickets for as low as $34. However, be on the lookout for offers from American Airlines and Southwest, as they are both options that can get you from Illinois to St. Louis for a low price.

  • What are the most popular routes from Illinois to St. Louis?

    When deciding which route to take from Illinois to St. Louis consider Chicago O'Hare Intl - Lambert-St Louis, Chicago Midway - Lambert-St Louis or Springfield Capital - Lambert-St Louis as they are the most popular.

  • What are the most reliable airlines from Illinois to St. Louis?

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Illinois to St. Louis on time: Turkish Airlines (88%), Envoy Air (85%), Republic Airways (83%).

  • What are the cheapest flights from Illinois to St. Louis?

    Looking at all options, your cheapest flight can be booked for $58. While the most popular route (Chicago O'Hare Intl - Lambert-St Louis) can be booked for $117 on average, our data indicates $245 when flying from Illinois to St. Louis.

  • Can I find deals for flights from Illinois to St. Louis that include hotel bookings?

    Yes. In addition to deals on Illinois to St. Louis flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Illinois to St. Louis?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Illinois to St. Louis.

  • Can I find deals for business class flights from Illinois to St. Louis?

    Yes. Cheapflights offers flight deals from Illinois to St. Louis by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Illinois to St. Louis?

    Currently, August is the cheapest month in which you can book a flight from Illinois to St. Louis (average of $77). Flying from Illinois to St. Louis in July is currently the most expensive (average of $172). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
Edwardsville
O'Fallon
Fairview Heights
Maryland Heights
Collinsville
Swansea
Eureka
Glencoe
St. Peters
Chesterfield
Alton
Farmington
Festus

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Illinois to St. Louis

See prices for flight routes from nearby airports that may be better suited for you.
John F Kennedy Intl to Kansas City flights
LaGuardia to Kansas City flights
Newark to St. Louis flights
John F Kennedy Intl to St. Louis flights
Los Angeles to Kansas City flights
LaGuardia to St. Louis flights
Newark to Kansas City flights
Denver to Kansas City flights
Dallas/Fort Worth to Kansas City flights
Boston to Kansas City flights
Dulles Intl to Kansas City flights
Dallas/Fort Worth to St. Louis flights
O'Hare Intl to Kansas City flights
Minneapolis to Kansas City flights
Denver to St. Louis flights
Dulles Intl to St. Louis flights
Hobby to Kansas City flights
Miami to Kansas City flights
Los Angeles to St. Louis flights
San Francisco to Kansas City flights
Reagan-National to Kansas City flights
San Francisco to St. Louis flights
Hobby to St. Louis flights
Boston to St. Louis flights
O'Hare Intl to St. Louis flights
Baltimore to Kansas City flights
Atlanta to St. Louis flights
Atlanta to Kansas City flights
Baltimore to St. Louis flights
George Bush Intcntl to Kansas City flights
Sky Harbor Intl to Kansas City flights
Ontario to Kansas City flights
Orlando to Kansas City flights
Minneapolis to St. Louis flights
Detroit to St. Louis flights
George Bush Intcntl to St. Louis flights
Seattle to Kansas City flights
Seattle to St. Louis flights
Orlando to St. Louis flights
Midway to Kansas City flights
Portland to Kansas City flights
Sky Harbor Intl to St. Louis flights
Fort Lauderdale to St. Louis flights
Austin to St. Louis flights
Raleigh to Kansas City flights
Philadelphia to Kansas City flights
Love Field to Kansas City flights
Philadelphia to St. Louis flights
Fort Lauderdale to Kansas City flights
San Diego to St. Louis flights

Top 4 airlines flying from Illinois to St. Louis

Discover the top 4 airlines that operate flights from Illinois to St. Louis. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated December 12, 2025.
AirlineCheapestAverageFlexibilityOn-time
SouthwestCheapest$77Average$387FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$115Average$299FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$144Average$300FlexibilityNo cancel feeOn-time69%
Southern / MokuleleCheapest$145Average$213FlexibilityNo cancel feeOn-timeN/A

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.