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$70+ Cheap flights from St. Louis (STL) to Chicago (CHI)

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 4/24. Fares are subject to change and may not be available on all flights or dates of travel.
STL — CHI
Apr 25 — May 21
Sat 4/25
Sat 5/2
1 adult, Economy
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Cheapflights Tip: The best prices from Lambert-St Louis to Chicago are usually found in August or September, booked 52 days in advance, depart on a Friday or Thursday and return on a Thursday

Cheap flight deals from St. Louis to Chicago

Cheapest flights from St. Louis to Chicago
Explore the most affordable flight options available from St. Louis to Chicago. Find the lowest fares from popular airlines and budget airlines, with prices last updated on March 26, 2026.

This Frontier deal was found by Cheapflights users on 3/23. 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.
Tue 4/711:21 am
STL
-
MDW
1 stop8h 46m
Frontier
Thu 4/96:00 am
MDW
-
STL
1 stop11h 34m
Frontier
Deal found 3/23$180
This Frontier deal was found by Cheapflights users on 3/23. 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 4/84:59 pm
STL
-
ORD
1 stop6h 37m
Frontier
Fri 4/105:05 pm
ORD
-
STL
1 stop6h 53m
Frontier
Deal found 3/23$180
This Frontier deal was found by Cheapflights users on 3/24. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/1611:25 am
STL
-
MDW
1 stop10h 54m
Frontier
Mon 4/209:14 am
MDW
-
STL
1 stop14h 05m
Frontier
Deal found 3/24$181
This Frontier deal was found by Cheapflights users on 3/24. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/1611:25 am
STL
-
ORD
1 stop11h 14m
Frontier
Mon 4/206:00 am
ORD
-
STL
1 stop17h 19m
Frontier
Deal found 3/24$181
This Kiwi.com deal was found by Cheapflights users on 3/23. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/56:41 pm
STL
-
ORD
1 stop13h 14m
Frontier
Wed 5/69:42 pm
ORD
-
STL
1 stop21h 41m
Frontier
Deal found 3/23$190
This Expedia deal was found by Cheapflights users on 3/22. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/88:08 pm
STL
-
ORD
1 stop24h 29m
Frontier
Sat 5/165:30 pm
ORD
-
STL
1 stop6h 51m
Frontier
Deal found 3/22$191
This Kiwi.com deal was found by Cheapflights users on 3/24. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/56:41 pm
STL
-
MDW
1 stop27h 21m
Frontier
Tue 5/126:00 am
MDW
-
STL
1 stop26h 55m
Frontier
Deal found 3/24$196
This Kiwi.com deal was found by Cheapflights users on 3/24. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/56:41 pm
STL
-
ORD
1 stop13h 14m
Frontier
Tue 5/126:55 am
ORD
-
STL
1 stop26h 00m
Frontier
Deal found 3/24$196
This Kiwi.com deal was found by Cheapflights users on 3/25. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/228:23 pm
STL
-
ORD
1 stop15h 09m
Frontier
Wed 4/296:08 pm
ORD
-
STL
2 stops25h 13m
Frontier
Deal found 3/25$200
This Frontier deal was found by Cheapflights users on 3/22. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/2311:25 am
STL
-
MDW
1 stop8h 06m
Frontier
Sun 4/262:00 pm
MDW
-
STL
1 stop9h 19m
Frontier
Deal found 3/22$201
This Frontier deal was found by Cheapflights users on 3/25. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/711:21 am
STL
-
ORD
1 stop11h 18m
Frontier
Wed 4/84:21 pm
ORD
-
STL
1 stop7h 04m
Frontier
Deal found 3/25$201
This Kiwi.com deal was found by Cheapflights users on 3/25. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/2311:25 am
STL
-
MDW
1 stop8h 06m
Frontier
Tue 4/282:15 pm
MDW
-
STL
1 stop16h 35m
Frontier
Deal found 3/25$204

Find flight deals from St. Louis to Chicago

Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Chicago (CHI). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated March 26, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$180
(Frontier)

One-way from

$70
(Frontier)

Popular in

January

Cheapest in

August

Average price

$310

Good round-trip deal

$327 or less

Good one-way deal

$201 or less
Provider with most accurate pricing for Lambert-St Louis-Chicago (CHI) flight deals.
Search Deals
Provider most trusted by Cheapflights users for Lambert-St Louis-Chicago (CHI) flights.
Search Deals
From Lambert-St Louis to Chicago (CHI)
Search Deals
One-way flight from Lambert-St Louis to Chicago (CHI)
Search Deals
Highest demand for flights based on searches. 28% potential increase in price ($122 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 6% potential price decrease ($18 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in March 2026
Search Deals
Price to beat on a round-trip flight from Lambert-St Louis to Chicago (CHI).
Search Deals
Price to beat on a one-way flight from Lambert-St Louis to Chicago (CHI).
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from St. Louis to Chicago 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 March 26, 2026.
Use the filters below to find and compare flights from St. Louis to Chicago that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip
Quickest round-trip

St. LouisChicago

STL - MDW

STLMDW

Lambert-St Louis

Tue 4/21

3:55 pm-5:05 pm

Nonstop1h 10m

Chicago Midway

Tue 4/28

1:55 pm-3:05 pm

Nonstop1h 10m

$215

St. LouisChicago

STL - MDW

STLMDW

Lambert-St Louis

Tue 5/5

8:45 pm-9:50 pm

Nonstop1h 05m

Chicago Midway

Wed 5/6

11:35 am-5:55 pm

2 stops6h 20m

$228

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Wed 5/20

6:57 pm-11:59 pm

1 stop5h 02m

Chicago O'Hare Intl

Wed 5/27

7:07 am-12:20 pm

1 stop5h 13m

$233

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Tue 4/21

5:45 am-11:10 am

1 stop5h 25m

Chicago O'Hare Intl

Tue 5/5

2:40 pm-7:15 pm

1 stop4h 35m

$234

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Sun 5/10

4:19 pm-11:13 pm

1 stop6h 54m

Chicago O'Hare Intl

Sun 5/17

5:30 pm-12:21 am

1 stop6h 51m

$247

St. LouisChicago

STL - MDW

STLMDW

Lambert-St Louis

Sat 5/2

10:35 am-2:25 pm

1 stop3h 50m

Chicago Midway

Mon 5/4

11:40 am-12:55 pm

Nonstop1h 15m

$271

St. LouisChicago

STL - MDW

STLMDW

Lambert-St Louis

Thu 6/4

12:40 pm-1:45 pm

Nonstop1h 05m

Chicago Midway

Mon 6/8

6:40 pm-12:05 am

1 stop5h 25m

$271

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Sat 5/2

1:03 pm-8:16 pm

1 stop7h 13m

Chicago O'Hare Intl

Mon 5/4

5:04 pm-8:44 pm

1 stop3h 40m

$279

St. LouisChicago

STL - MDW

STLMDW

Lambert-St Louis

Fri 5/1

9:40 pm-10:45 pm

Nonstop1h 05m

Chicago Midway

Sat 5/9

7:45 am-1:35 pm

1 stop5h 50m

$294

St. LouisChicago

STL - MDW

STLMDW

Lambert-St Louis

Tue 5/5

1:45 pm-2:55 pm

Nonstop1h 10m

Chicago Midway

Tue 5/12

8:15 am-9:30 am

Nonstop1h 15m

$297

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/23

Showing 1-10 of 41 resultsSorted by cheapest first
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Compare providers for flights from St. Louis to Chicago

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from St. Louis to Chicago in March.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars
Justfly.comPrice Accuracy3 starsTrust Score*3 stars
Kiwi.comPrice Accuracy3 starsTrust Score*3 stars
CheapfaremartPrice Accuracy-Trust Score*1 star

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on St. Louis-Chicago flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on St. Louis-Chicago flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from St. Louis-Chicago flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on St. Louis-Chicago flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for St. Louis-Chicago flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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

Have a flexible travel schedule? Discover the best time to fly to Chicago from St. Louis 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 St. Louis to Chicago

How far ahead should I book a flight from St. Louis to Chicago?

Use this chart to determine the optimal time to book a round-trip flight from St. Louis to Chicago. Price data was last updated on March 13, 2026.

The price you pay for your flight from St. Louis to Chicago may vary depending on when you book. For the best chance of a lower fare, look to book 51 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

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

Currently, November is the cheapest month in which you can book a flight from St. Louis to Chicago (average of $77). Flying from St. Louis to Chicago in March 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 STL to CHI?

Find hourly flight availability from St. Louis to Chicago. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated March 26, 2026.

It’s optimal to fly from St. Louis to Chicago in the morning. By choosing this option you can save up to 33% on the cost of your flight, compared to a flight at noon.

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

Use this chart to determine the cheapest time to fly round-trip from St. Louis to Chicago. Price data was last updated on March 23, 2026.

Travelers seeking maximum savings on their St. Louis to Chicago flight should consider departing on Wednesday 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 St. Louis to Chicago

Explore weekly flight availability from St. Louis to Chicago. 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 March 26, 2026.

The most flights from STL to CHI are scheduled on a Thursday (73 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (11 on average).

How much does it cost to fly round-trip from St. Louis to Chicago?

The best insider tips for St. Louis to Chicago flights

AI-powered summary based on content written by travel experts. AI can make mistakes.
Cheapflights partnered with top experts to bring you the best recommendations for your St. Louis to Chicago trip
Our travel experts
Ramsey Qubein

Ramsey Qubein

Expert on ORD and MDW

An avid traveler and aviation expert who has visited 173 countries, all 50 states and seven continents, Ramsey Qubein flies nearly 400,000 miles a year. As a North Carolina-based freelance journalist for publications including Conde Nast Traveler, Forbes, USA Today and Bloomberg among others, he explores the latest trends in aviation, hospitality, cruises and business.

Read more
Taryn White

Taryn White

Expert on STL

Taryn White is a freelance travel writer, digital creator, and travel advisor who has visited nearly 100 countries and all 50 states. She’s familiar with many airports and enjoys beach hopping, boutique hotels, spa experiences, and exploring local culture. Her work has appeared in Travel + Leisure, Condé Nast Traveler, National Geographic, Smithsonian Magazine, AFAR, and more.

Read more

Reviews of airlines servicing Chicago

Get insights into the airlines that provide service to Chicago. 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 Chicago. Reviews last updated March 26, 2026.
Read through reviews of airlines operating flights from St. Louis to Chicago, such as Southwest,United Airlines, andAmerican Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,331 reviews

Food

7.0

Crew

8.6

Overall

8.0

Entertainment

7.5

Boarding

8.1

Comfort

8.0

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.
Southwest
8.0
Very good
4,331 reviews
Southwest
8.0
Very good
4,331 reviews

Food

7.0

Crew

8.6

Overall

8.0

Entertainment

7.5

Boarding

8.1

Comfort

8.0

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.
United Airlines
7.4
Good
9,493 reviews
Southwest
8.0
Very good
4,331 reviews

Food

7.0

Crew

8.6

Overall

8.0

Entertainment

7.5

Boarding

8.1

Comfort

8.0

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.
American Airlines
7.1
Good
11,499 reviews
Southwest
8.0
Very good
4,331 reviews

Food

7.0

Crew

8.6

Overall

8.0

Entertainment

7.5

Boarding

8.1

Comfort

8.0

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.
Southern / Mokulele
6.5
Okay
27 reviews
Southwest
8.0
Very good
4,331 reviews

Food

7.0

Crew

8.6

Overall

8.0

Entertainment

7.5

Boarding

8.1

Comfort

8.0

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Chicago. 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 from for flights from St. Louis to Chicago?

    If you book a flight to Chicago from St. Louis, you will be flying from 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. There are 37 flights from Lambert-St Louis to Chicago per day from 4 different airlines.

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

    Departing from St. Louis to Chicago will take you 5h 02m. The distance between St. Louis and Chicago is about 258 mi. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.

  • What are the cheapest airlines flying from St. Louis to Chicago round-trip?

    Cheapflights users have booked flights from St. Louis to Chicago round-trip from $97. Other airlines that can offer you cheap pricing are Southwest, from $117, and United Airlines, from $125. These flights start at 68% lower than the current average price 3 months from now.

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

    To fly one-way, consider booking your trip with Southwest, which is currently one of the cheapest options available, starting at $48. American Airlines flights start at $50 while deals on United Airlines start at $75 one-way.

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

    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 St. Louis to Chicago on time: Republic Airways (82%), Turkish Airlines (74%), Japan Airlines (74%).

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

    The cheapest flight price from St. Louis to Chicago is $125. On average you can expect to pay $865. The most popular route, (Lambert-St Louis - Chicago O'Hare Intl), can usually be booked for $185.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from St. Louis to Chicago 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 St. Louis to Chicago?

    Currently, November is the cheapest month in which you can book a flight from St. Louis to Chicago (average of $77). Flying from St. Louis to Chicago in March 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 Chicago?

Book flights to Chicago if you plan to visit one of these locations
Lansing
Merrillville
Hammond
Porter
Benton Harbor

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Top 4 airlines flying from St. Louis to Chicago

Discover the top 4 airlines that operate flights from St. Louis to Chicago. 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 March 26, 2026.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$97Average$293FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$117Average$340FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$125Average$346FlexibilityNo cancel feeOn-time69%
Southern / MokuleleCheapest$140Average$198FlexibilityNo cancel feeOn-timeN/A

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