St. Louis

$46+ 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 8/20. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — STL
Jul 30 — Aug 61
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Cheap 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 July 25, 2025.

Round-trip from

$77
(Southwest)

One-way from

$46
(American Airlines)

Popular in

July

Cheapest in

September

Average price

$361

Good round-trip deal

$151 or less

Good one-way deal

$106 or less
From Illinois to Lambert-St Louis
One-way flight from Illinois to Lambert-St Louis
Highest demand for flights based on searches. 2% potential increase in price ($6 potential increase over avg. RT price).
Cheapest flight prices on average. 2% potential price decrease ($7 potential savings vs. average RT price).
Average for round-trip flights in July 2025
Price to beat on a round-trip flight from Illinois to Lambert-St Louis.
Price to beat on a one-way flight from Illinois to Lambert-St Louis.

Find 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 July 25, 2025.

This Southwest deal was found by Cheapflights users on 7/24. 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 8/1411:45 amMDW - STL
Nonstop1h 10mSouthwest
Mon 8/1811:50 amSTL - MDW
Nonstop1h 05mSouthwest
Deal found 7/24$77
This United Airlines deal was found by Cheapflights users on 7/23. 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 8/272:20 pmORD - STL
Nonstop1h 24mUnited Airlines
Sat 8/305:30 pmSTL - ORD
Nonstop1h 25mUnited Airlines
Deal found 7/23$77
This American Airlines deal was found by Cheapflights users on 7/22. 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.
Thu 9/1810:34 pmORD - STL
Nonstop1h 14mAmerican Airlines
Tue 10/72:15 pmSTL - ORD
Nonstop1h 23mAmerican Airlines
Deal found 7/22$91
This Southwest deal was found by Cheapflights users on 7/24. 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 8/145:45 pmORD - STL
1 stop4h 50mSouthwest
Mon 8/183:55 pmSTL - ORD
1 stop5h 35mSouthwest
Deal found 7/24$97
This SmartFares deal was found by Cheapflights users on 7/22. 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 SmartFares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/58:15 amORD - STL
1 stop3h 45mSouthern / Mokulele
Fri 9/129:20 amSTL - ORD
1 stop6h 59mSouthern / Mokulele
Deal found 7/22$172
This Delta deal was found by Cheapflights users on 7/24. 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.
Sat 9/209:20 amMDW - STL
1 stop6h 54mDelta
Sat 10/43:55 pmSTL - MDW
1 stop5h 15mDelta
Deal found 7/24$177
This Delta deal was found by Cheapflights users on 7/24. 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.
Fri 8/225:45 amORD - STL
1 stop4h 12mDelta
Wed 8/276:40 amSTL - ORD
1 stop6h 05mDelta
Deal found 7/24$177
This Frontier deal was found by Cheapflights users on 7/23. 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 7/3011:28 amORD - STL
1 stop12h 19mFrontier
Thu 7/312:36 pmSTL - ORD
1 stop9h 46mFrontier
Deal found 7/23$188
This Trip.com deal was found by Cheapflights users on 7/23. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/142:23 pmORD - STL
Nonstop1h 24mMultiple Airlines
Mon 8/181:00 pmSTL - ORD
1 stop3h 32mMultiple Airlines
Deal found 7/23$190
This Gotogate deal was found by Cheapflights users on 7/24. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/2512:35 pmMDW - STL
1 stop20h 36mFrontier
Sat 7/262:52 pmSTL - MDW
1 stop7h 43mFrontier
Deal found 7/24$197
This American Airlines deal was found by Cheapflights users on 7/24. 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.
Sun 7/276:36 pmSPI - STL
1 stop21h 46mAmerican Airlines
Thu 7/314:52 pmSTL - SPI
1 stop49h 06mAmerican Airlines
Deal found 7/24$1,076

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 July 25, 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

Thu 8/14

11:45 am-12:55 pm

Nonstop1h 10m

Lambert-St Louis

Mon 8/18

11:50 am-12:55 pm

Nonstop1h 05m

$77

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Thu 8/14

2:23 pm-3:47 pm

Nonstop1h 24m

Lambert-St Louis

Mon 8/18

8:00 am-9:25 am

Nonstop1h 25m

$77

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Thu 9/18

10:34 pm-11:48 pm

Nonstop1h 14m

Lambert-St Louis

Tue 10/7

2:15 pm-3:38 pm

Nonstop1h 23m

$91

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Thu 8/14

5:45 pm-10:35 pm

1 stop4h 50m

Lambert-St Louis

Mon 8/18

3:55 pm-9:30 pm

1 stop5h 35m

$97

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Fri 9/5

8:15 am-12:00 pm

1 stop3h 45m

Lambert-St Louis

Fri 9/12

9:20 am-4:19 pm

1 stop6h 59m

$172

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

Sat 9/20

9:20 am-4:14 pm

1 stop6h 54m

Lambert-St Louis

Sat 10/4

3:55 pm-9:10 pm

1 stop5h 15m

$177

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Fri 8/22

5:45 am-9:57 am

1 stop4h 12m

Lambert-St Louis

Wed 8/27

6:40 am-12:45 pm

1 stop6h 05m

$177

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Tue 7/29

11:28 am-11:47 pm

1 stop12h 19m

Lambert-St Louis

Sun 8/3

2:36 pm-12:22 am

1 stop9h 46m

$188

ChicagoSt. Louis

ORD - STL

ORDSTL

Chicago O'Hare Intl

Thu 8/14

2:23 pm-3:47 pm

Nonstop1h 24m

Lambert-St Louis

Mon 8/18

1:00 pm-4:32 pm

1 stop3h 32m

$190

ChicagoSt. Louis

MDW - STL

MDWSTL

Chicago Midway

Thu 8/7

6:20 am-1:34 pm

1 stop7h 14m

Lambert-St Louis

Sun 8/10

2:36 pm-11:17 pm

1 stop8h 41m

$198

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/22

Showing 1-10 of 24 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 $311). Flying from Illinois to St. Louis in March is currently the most expensive (average of $356). 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 July 25, 2025.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Illinois to St. Louis as you normally would.

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 July 25, 2025.

The most flights from USIL to STL are scheduled on a Thursday (71 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (46 on average).

Reviews of airlines servicing St. Louis

Get insights into the airlines that provide service to St. Louis. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to St. Louis. Reviews last updated July 25, 2025.
Peruse reviews from past customers who have flown with Southwest, Delta, and United Airlines from Illinois to St. Louis to help guide your decision. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.

Crew

8.6

Comfort

8.0

Entertainment

7.6

Food

7.0

Boarding

8.1

Overall

8.0

Reviews

1 / 20
8.0
Excellent

John,May 2025

PVD - BNA

It’s southwest so no frills but clean, efficient and got me to my location.

Crew

8.6

Comfort

8.0

Entertainment

7.6

Food

7.0

Boarding

8.1

Overall

8.0

Reviews

1 / 20
8.0
Excellent

John,May 2025

PVD - BNA

It’s southwest so no frills but clean, efficient and got me to my location.
8.0
Very good

Crew

8.6

Comfort

8.0

Entertainment

7.6

Food

7.0

Boarding

8.1

Overall

8.0

Reviews

1 / 20
8.0
Excellent

John,May 2025

PVD - BNA

It’s southwest so no frills but clean, efficient and got me to my location.

Crew

8.6

Comfort

8.0

Entertainment

7.6

Food

7.0

Boarding

8.1

Overall

8.0

Reviews

1 / 20
8.0
Excellent

John,May 2025

PVD - BNA

It’s southwest so no frills but clean, efficient and got me to my location.

Crew

8.6

Comfort

8.0

Entertainment

7.6

Food

7.0

Boarding

8.1

Overall

8.0

Reviews

1 / 20
8.0
Excellent

John,May 2025

PVD - BNA

It’s southwest so no frills but clean, efficient and got me to my location.

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.

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

    The cheapest airline one-way is American Airlines, with whom users have recently found tickets for as low as $46. However, be on the lookout for offers from Southwest and United 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?

  • 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: Republic Airways (88%), Envoy Air (88%), SkyWest Airlines (83%).

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

    Looking at all options, your cheapest flight can be booked for $45. While the most popular route (Chicago O'Hare Intl - Lambert-St Louis) can be booked for $77 on average our data indicates $229 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 $311). Flying from Illinois to St. Louis in March is currently the most expensive (average of $356). 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
O'Fallon
Maryland Heights
Fairview Heights
Collinsville
Eureka
St. Peters
Glencoe
Alton
Festus
Chesterfield
Farmington

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Alternative routes for Illinois to St. Louis

See prices for flight routes from nearby airports that may be better suited for you.

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 July 25, 2025.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$115Average$268FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$116Average$328FlexibilityNo cancel feeOn-time63%
Southern / MokuleleCheapest$118Average$212FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$152Average$321FlexibilityNo cancel feeOn-time69%

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