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$46+ 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 8/27. Fares are subject to change and may not be available on all flights or dates of travel.
STL — CHI
Aug 2 — Aug 91
Sat 8/2
Sat 8/9
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 86 days in advance, depart on a Thursday or Friday and return on a Thursday

Cheap 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 July 28, 2025.

Round-trip from

$77
(Southwest)

One-way from

$46
(Southwest)

Popular in

April

Cheapest in

August

Average price

$240

Good round-trip deal

$246 or less

Good one-way deal

$159 or less
From Lambert-St Louis to Chicago (CHI)
Search Deals
One-way flight from Lambert-St Louis to Chicago (CHI)
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Highest demand for flights based on searches. 11% potential increase in price ($31 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($4 potential savings vs. average RT price).
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Average for round-trip flights in July 2025
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Price to beat on a round-trip flight from Lambert-St Louis to Chicago (CHI).
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Price to beat on a one-way flight from Lambert-St Louis to Chicago (CHI).
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Find 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 July 28, 2025.

This Southwest deal was found by Cheapflights users on 7/25. 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.
Sat 8/236:00 pmSTL - MDW
Nonstop1h 05mSouthwest
Mon 8/252:35 pmMDW - STL
Nonstop1h 10mSouthwest
Deal found 7/25$77
This United Airlines deal was found by Cheapflights users on 7/25. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/223:20 pmSTL - ORD
Nonstop1h 25mUnited Airlines
Thu 9/259:25 amORD - STL
Nonstop1h 24mUnited Airlines
Deal found 7/25$77
This American Airlines deal was found by Cheapflights users on 7/26. 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.
Sat 9/136:10 amSTL - ORD
Nonstop1h 20mAmerican Airlines
Sat 9/137:10 pmORD - STL
Nonstop1h 22mAmerican Airlines
Deal found 7/26$91
This Southwest deal was found by Cheapflights users on 7/25. 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.
Mon 9/223:55 pmSTL - ORD
1 stop5h 35mSouthwest
Thu 9/255:45 pmORD - STL
1 stop4h 50mSouthwest
Deal found 7/25$97
This Tripair deal was found by Cheapflights users on 7/27. 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 Tripair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/235:30 pmSTL - ORD
Nonstop1h 25mMultiple Airlines
Sun 8/248:15 amORD - STL
1 stop3h 55mMultiple Airlines
Deal found 7/27$159
This Jettzy deal was found by Cheapflights users on 7/26. 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 Jettzy is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/291:00 pmSTL - ORD
1 stop18h 37mSouthern / Mokulele
Tue 9/21:10 pmORD - STL
1 stop19h 30mSouthern / Mokulele
Deal found 7/26$166
This Delta deal was found by Cheapflights users on 7/28. 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 9/1310:15 amSTL - MDW
1 stop5h 11mDelta
Tue 9/1610:35 amMDW - STL
1 stop5h 30mDelta
Deal found 7/28$177
This Delta deal was found by Cheapflights users on 7/28. 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 9/137:10 amSTL - ORD
1 stop7h 23mDelta
Sat 9/207:20 amORD - STL
1 stop7h 28mDelta
Deal found 7/28$177
This Frontier deal was found by Cheapflights users on 7/27. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/22:52 pmSTL - MDW
1 stop7h 43mFrontier
Sat 8/96:20 amMDW - STL
1 stop7h 39mFrontier
Deal found 7/27$178
This Frontier deal was found by Cheapflights users on 7/27. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/22:52 pmSTL - ORD
1 stop8h 37mFrontier
Sat 8/95:01 amORD - STL
1 stop8h 58mFrontier
Deal found 7/27$178

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 July 28, 2025.
Use the filters below to find and compare flights from St. Louis to Chicago that are best for you.

Fly from

St. Louis

Fly to

Chicago

Route

Depart

Return

Price

St. LouisChicago

STL - MDW

STLMDW

Lambert-St Louis

Sat 8/23

6:00 pm-7:05 pm

Nonstop1h 05m

Chicago Midway

Mon 8/25

2:35 pm-3:45 pm

Nonstop1h 10m

$77

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Mon 9/22

3:20 pm-4:45 pm

Nonstop1h 25m

Chicago O'Hare Intl

Thu 9/25

9:25 am-10:49 am

Nonstop1h 24m

$77

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Sat 9/13

6:10 am-7:30 am

Nonstop1h 20m

Chicago O'Hare Intl

Sat 9/13

7:10 pm-8:32 pm

Nonstop1h 22m

$91

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Mon 9/22

3:55 pm-9:30 pm

1 stop5h 35m

Chicago O'Hare Intl

Thu 9/25

5:45 pm-10:35 pm

1 stop4h 50m

$97

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Sat 8/23

5:30 pm-6:55 pm

Nonstop1h 25m

Chicago O'Hare Intl

Sun 8/24

8:15 am-12:10 pm

1 stop3h 55m

$159

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Fri 8/29

1:00 pm-7:37 am

1 stop18h 37m

Chicago O'Hare Intl

Tue 9/2

1:10 pm-8:40 am

1 stop19h 30m

$166

St. LouisChicago

STL - MDW

STLMDW

Lambert-St Louis

Sat 9/13

10:15 am-3:26 pm

1 stop5h 11m

Chicago Midway

Tue 9/16

10:35 am-4:05 pm

1 stop5h 30m

$177

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Sat 9/13

7:10 am-2:33 pm

1 stop7h 23m

Chicago O'Hare Intl

Sat 9/20

7:20 am-2:48 pm

1 stop7h 28m

$177

St. LouisChicago

STL - MDW

STLMDW

Lambert-St Louis

Sat 8/2

2:52 pm-10:35 pm

1 stop7h 43m

Chicago Midway

Sat 8/9

6:20 am-1:59 pm

1 stop7h 39m

$178

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Sat 8/2

2:52 pm-11:29 pm

1 stop8h 37m

Chicago O'Hare Intl

Sat 8/9

5:01 am-1:59 pm

1 stop8h 58m

$178

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/28

Showing 1-10 of 22 results
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The best insider tips for St. Louis to Chicago flights

Snippets provided in this section are AI-generated based on a summarization of Cheapflights-commissioned articles. The articles are presented as-is, for general informational purposes only, and may not be up-to-date. The opinions contained in the articles are original to the author and reflect their authentic experience, which may vary significantly from the experience of others.
Cheapflights partnered with top experts to bring you the best recommendations for your St. Louis to Chicago trip
Airlines
Lufthansa

Economy Flex offers preferred seating and same-day flight changes, adding value over Light fares.


Lufthansa's Free Neighbor Seat option allows extra space for a fee, enhancing comfort.

Read more about Lufthansaby Blane Bachelor
Southwest

Southwest offers two free checked bags, even oversized, with Wanna Get Away fares.


Southwest's open seating policy allows seat choice based on check-in time, enhancing boarding efficiency.

Read more about Southwestby Marisa Garcia
United Airlines

Basic Economy allows a personal item only; no carry-on bags unless you're a MileagePlus member.


Prepay checked bags 24 hours before to save on fees, especially for domestic flights.

Read more about United Airlinesby Harriet Baskas
Airports
STL

Expect security screening at STL to take 5-10 minutes during off-peak times. Check real-time wait times online before heading to the airport.

Read more about STLby Taryn White
ORD

At ORD, expect long walks between terminals. Use the free shuttle train for easier navigation between terminals.

Read more about ORDby Ramsey Qubein
MDW

The Orange Line train connects MDW to downtown Chicago in under 30 minutes, offering a convenient and affordable transportation option.

Read more about MDWby Ramsey Qubein
Our travel experts
Blane Bachelor

Blane Bachelor

Expert on Lufthansa

Blane Bachelor

Blane Bachelor

Blane Bachelor is a journalist and editor specializing in travel and aviation who writes regularly for top global outlets. Born and raised in Florida, Blane has worked and lived in four countries, including the Netherlands, where she’s currently based with her family. Her favorite way to get to know a new destination is by running or riding a bike around town – or hearing a spooky ghost story about local history. She will always choose the window seat.

Read more
Marisa Garcia

Marisa Garcia

Expert on Southwest

Marisa Garcia

Marisa Garcia

Marisa knows planes inside and out, spending 16 years working on aircraft in hangars at airports around the world. She is an aviation industry expert, specialized in airline interiors and regulations. Ten years ago, she pivoted to journalism. She shares her insights in leading aviation, travel, and business publications and on her site FlightChic.

Read more
Harriet Baskas

Harriet Baskas

Expert on United Airlines

Harriet Baskas

Harriet Baskas

Harriet is an award-winning journalist who is happiest in an airport or an unusual museum. Her stories about airports, air travel, and the business of travel have appeared on NBC News, CNBC, USA TODAY, The Points Guy and other outlets. She is the creator of the StuckatTheAirport.com blog and the author of nine books. When not out on the road or exploring the latest airport amenities, she’s home in Seattle getting ready for the next adventure.

Read more
Ramsey Qubein

Ramsey Qubein

Expert on ORD and MDW

Ramsey Qubein

Ramsey Qubein

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

Taryn White

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

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 July 25, 2025.

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, August is the cheapest month in which you can book a flight from St. Louis to Chicago (average of $245). Flying from St. Louis to Chicago in March is currently the most expensive (average of $321). 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 July 28, 2025.

It’s optimal to fly from St. Louis to Chicago in the morning. By choosing this option you can save up to 51% 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 July 27, 2025.

Travelers seeking maximum savings on their St. Louis to Chicago flight should consider departing on Thursday mornings when fares are most often at their lowest. Saturday at noon 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 July 28, 2025.

The most flights from STL to CHI are scheduled on a Monday (81 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (63 on average).

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 July 28, 2025.
Read through reviews of airlines operating flights from St. Louis to Chicago, such as Southwest, Delta, and United Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,237 reviews

Comfort

8.0

Boarding

8.1

Entertainment

7.5

Crew

8.6

Overall

8.0

Food

7.0

Reviews

1 / 20
8.0
Excellent

Gina,Jul 2025

LAS - DEN

We experienced bad weather, which turned our 1.5 hour flight from Las Vegas to Denver, into 3.5. The pilot and crew kept us updated and explained that we had to circle and or possibly redirect to another airport. After circling for sometime, we were able to land smoothly in Denver. Thank you to all the flight crew, tower control, and all who got us to our destination safely.
Southwest
8.0
Very good
4,237 reviews
Southwest
8.0
Very good
4,237 reviews

Comfort

8.0

Boarding

8.1

Entertainment

7.5

Crew

8.6

Overall

8.0

Food

7.0

Reviews

1 / 20
8.0
Excellent

Gina,Jul 2025

LAS - DEN

We experienced bad weather, which turned our 1.5 hour flight from Las Vegas to Denver, into 3.5. The pilot and crew kept us updated and explained that we had to circle and or possibly redirect to another airport. After circling for sometime, we were able to land smoothly in Denver. Thank you to all the flight crew, tower control, and all who got us to our destination safely.
Delta
8.0
Very good
7,971 reviews
Southwest
8.0
Very good
4,237 reviews

Comfort

8.0

Boarding

8.1

Entertainment

7.5

Crew

8.6

Overall

8.0

Food

7.0

Reviews

1 / 20
8.0
Excellent

Gina,Jul 2025

LAS - DEN

We experienced bad weather, which turned our 1.5 hour flight from Las Vegas to Denver, into 3.5. The pilot and crew kept us updated and explained that we had to circle and or possibly redirect to another airport. After circling for sometime, we were able to land smoothly in Denver. Thank you to all the flight crew, tower control, and all who got us to our destination safely.
United Airlines
7.4
Good
8,893 reviews
Southwest
8.0
Very good
4,237 reviews

Comfort

8.0

Boarding

8.1

Entertainment

7.5

Crew

8.6

Overall

8.0

Food

7.0

Reviews

1 / 20
8.0
Excellent

Gina,Jul 2025

LAS - DEN

We experienced bad weather, which turned our 1.5 hour flight from Las Vegas to Denver, into 3.5. The pilot and crew kept us updated and explained that we had to circle and or possibly redirect to another airport. After circling for sometime, we were able to land smoothly in Denver. Thank you to all the flight crew, tower control, and all who got us to our destination safely.
American Airlines
7.2
Good
10,000 reviews
Southwest
8.0
Very good
4,237 reviews

Comfort

8.0

Boarding

8.1

Entertainment

7.5

Crew

8.6

Overall

8.0

Food

7.0

Reviews

1 / 20
8.0
Excellent

Gina,Jul 2025

LAS - DEN

We experienced bad weather, which turned our 1.5 hour flight from Las Vegas to Denver, into 3.5. The pilot and crew kept us updated and explained that we had to circle and or possibly redirect to another airport. After circling for sometime, we were able to land smoothly in Denver. Thank you to all the flight crew, tower control, and all who got us to our destination safely.

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 71 flights from Lambert-St Louis to Chicago per day from 4 different airlines.

  • 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 $77. Other airlines that can offer you cheap pricing are United Airlines, from $77, and American Airlines, from $91. 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 $46. United Airlines flights start at $46 while deals on Southern / Mokulele start at $84 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: Avianca (84%), Royal Jordanian (79%), Japan Airlines (79%).

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

    The cheapest flight price from St. Louis to Chicago is $121. On average you can expect to pay $1,690. The most popular route, (Lambert-St Louis - Chicago O'Hare Intl), can usually be booked for $91.

  • 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, August is the cheapest month in which you can book a flight from St. Louis to Chicago (average of $245). Flying from St. Louis to Chicago in March is currently the most expensive (average of $321). 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
Merrillville
Lansing
Hammond
Benton Harbor
Porter
Valparaiso
Chesterton

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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 July 28, 2025.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$115Average$271FlexibilityNo cancel feeOn-time71%
Southern / MokuleleCheapest$129Average$197FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$130Average$316FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$168Average$289FlexibilityNo cancel feeOn-time63%

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