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St. Louis

$67+ 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 2/23. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — STL
Jan 27 — Feb 31
Tue 1/27
Tue 2/3
1 adult, Economy
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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 28, 2025.

This eDestinos deal was found by Cheapflights users on 12/27. 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 stops23h 41mFrontier
Deal found 12/27$442
This Expedia deal was found by Cheapflights users on 12/26. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/2810:50 pmMDW - STL
1 stop11h 12mFrontier
Tue 12/3010:48 amSTL - MDW
1 stop11h 24mFrontier
Deal found 12/26$462
This Expedia deal was found by Cheapflights users on 12/26. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/307:00 amORD - STL
1 stop27h 02mFrontier
Thu 1/110:42 amSTL - ORD
1 stop7h 51mFrontier
Deal found 12/26$467
This Expedia deal was found by Cheapflights users on 12/26. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/287:00 amORD - STL
1 stop27h 02mFrontier
Tue 12/3010:48 amSTL - ORD
1 stop7h 45mFrontier
Deal found 12/26$487
This eDestinos deal was found by Cheapflights users on 12/26. 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.
Tue 12/301:14 pmORD - STL
2 stops44h 26mFrontier
Tue 1/135:11 pmSTL - ORD
2 stops23h 41mFrontier
Deal found 12/26$540
This United Airlines deal was found by Cheapflights users on 12/26. 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.
Tue 12/3010:50 amORD - STL
Nonstop1h 37mUnited Airlines
Tue 1/1311:20 amSTL - ORD
Nonstop1h 35mUnited Airlines
Deal found 12/26$590
This American Airlines deal was found by Cheapflights users on 12/26. 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.
Tue 12/306:03 pmORD - STL
Nonstop1h 28mAmerican Airlines
Tue 1/136:52 amSTL - ORD
1 stop6h 30mAmerican Airlines
Deal found 12/26$607
This American Airlines deal was found by Cheapflights users on 12/25. 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.
Mon 12/294:05 pmORD - STL
1 stop7h 50mAmerican Airlines
Wed 12/315:00 amSTL - ORD
1 stop28h 21mAmerican Airlines
Deal found 12/25$614
This Kiwi.com deal was found by Cheapflights users on 12/26. 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 12/315:00 amORD - STL
1 stop29h 56mMultiple Airlines
Sun 1/410:57 amSTL - ORD
2 stops26h 13mMultiple Airlines
Deal found 12/26$618
This Southwest deal was found by Cheapflights users on 12/25. 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.
Tue 12/304:20 pmMDW - STL
Nonstop1h 10mSouthwest
Tue 12/306:30 pmSTL - MDW
Nonstop1h 10mSouthwest
Deal found 12/25$723
This Southwest deal was found by Cheapflights users on 12/26. 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.
Mon 12/2910:00 amMDW - STL
Nonstop1h 25mSouthwest
Wed 12/318:30 amSTL - MDW
1 stop4h 15mSouthwest
Deal found 12/26$733
This Southwest deal was found by Cheapflights users on 12/27. 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 12/3110:05 amMDW - STL
1 stop6h 00mSouthwest
Fri 1/27:50 amSTL - MDW
1 stop4h 50mSouthwest
Deal found 12/27$743

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 28, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$145
(Kiwi.com)

One-way from

$67
(Kiwi.com)

Popular in

October

Cheapest in

November

Average price

$274

Good round-trip deal

$61 or less

Good one-way deal

$138 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 ($7 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($7 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 28, 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

ORD - STL

ORDSTL

Chicago O'Hare Intl

Wed 1/21

10:48 am-11:33 pm

1 stop12h 45m

Lambert-St Louis

Wed 1/28

5:42 pm-10:41 am

1 stop16h 59m

$145

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Tue 2/10

7:50 pm-9:15 pm

Nonstop1h 25m

Lambert-St Louis

Tue 2/17

9:59 am-11:26 am

Nonstop1h 27m

$154

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

Sat 1/31

7:40 pm-8:55 pm

Nonstop1h 15m

Lambert-St Louis

Mon 2/2

5:55 pm-7:05 pm

Nonstop1h 10m

$157

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

Sat 2/21

7:45 am-9:05 am

Nonstop1h 20m

Lambert-St Louis

Mon 2/23

5:30 pm-6:40 pm

Nonstop1h 10m

$157

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

Sat 1/24

7:40 pm-8:55 pm

Nonstop1h 15m

Lambert-St Louis

Sat 1/31

7:40 am-8:50 am

Nonstop1h 10m

$167

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Sat 1/24

1:00 pm-2:28 pm

Nonstop1h 28m

Lambert-St Louis

Sat 1/31

11:20 am-12:55 pm

Nonstop1h 35m

$171

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

Thu 1/29

6:10 am-7:35 am

Nonstop1h 25m

Lambert-St Louis

Mon 2/2

5:55 pm-7:05 pm

Nonstop1h 10m

$171

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Sat 1/31

4:42 pm-6:13 pm

Nonstop1h 31m

Lambert-St Louis

Mon 2/2

8:31 am-10:00 am

Nonstop1h 29m

$172

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

Tue 2/10

6:14 pm-11:37 pm

1 stop5h 23m

Lambert-St Louis

Tue 2/17

6:35 am-12:46 pm

1 stop6h 11m

$173

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

Tue 1/20

7:16 pm-11:25 pm

1 stop4h 09m

Lambert-St Louis

Wed 1/21

6:10 am-1:09 pm

1 stop6h 59m

$173

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/28

Showing 1-10 of 45 results
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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 28, 2025.

It’s typically best to fly out from Illinois to St. Louis at noon. Doing so could potentially save you 16% on the flight price compared to flying in the morning, 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 27, 2025.

Travelers seeking maximum savings on their Illinois to St. Louis flight should consider departing on Tuesday at noon 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 28, 2025.

The most flights from USIL to STL are scheduled on a Friday (59 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (34 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 American Airlines, Southwest, and United Airlines fly from Illinois to St. Louis in about 1h 15m. The time it takes to get you to your destination is usually consistent. There are 251 mi between Illinois and St. Louis. Generally, flights for this route are nonstop.

  • 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 Southwest and American Airlines, 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: Envoy Air (81%), Turkish Airlines (79%), Austrian Airlines (76%).

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

    Looking at all options, your cheapest flight can be booked for $78. While the most popular route (Chicago O'Hare Intl - Lambert-St Louis) can be booked for $153 on average, our data indicates $341 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
Swansea
Fairview Heights
Maryland Heights
Collinsville
Eureka
Glencoe
Chesterfield
Alton
Farmington
Festus

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for Illinois to St. Louis

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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 28, 2025.
AirlineCheapestAverageFlexibilityOn-time
SouthwestCheapest$77Average$387FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$115Average$299FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$144Average$307FlexibilityNo cancel feeOn-time69%
Southern / MokuleleCheapest$145Average$213FlexibilityNo cancel feeOn-timeN/A

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