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O'Hare Intl

$49+ Cheap flights from St. Louis (STL) to O'Hare Intl (ORD)

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 10/25. Fares are subject to change and may not be available on all flights or dates of travel.
STL — ORD
Oct 17 — Oct 241
Fri 10/17
Fri 10/24
1 adult, Economy
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Cheapflights Tip: The best prices from Lambert-St Louis to Chicago O'Hare Intl are usually found in September or April, booked 75 days in advance, depart on a Thursday or Friday and return on a Friday

Cheap flight deals from St. Louis to O'Hare Intl

Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to O'Hare Intl (ORD). 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 September 17, 2025.

Round-trip from

$97
(United Airlines)

One-way from

$49
(United Airlines)

Popular in

July

Cheapest in

September

Average price

$216

Good round-trip deal

$469 or less

Good one-way deal

$185 or less
From Lambert-St Louis to Chicago O'Hare Intl
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One-way flight from Lambert-St Louis to Chicago O'Hare Intl
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Highest demand for flights based on searches. 7% potential increase in price ($20 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($6 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Price to beat on a round-trip flight from Lambert-St Louis to Chicago O'Hare Intl.
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Price to beat on a one-way flight from Lambert-St Louis to Chicago O'Hare Intl.
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Find flight deals from St. Louis to O'Hare Intl

Cheapest flights from St. Louis to O'Hare Intl
Explore the most affordable flight options available from St. Louis to O'Hare Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 17, 2025.

This United Airlines deal was found by Cheapflights users on 9/16. 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 10/155:00 amSTL - ORD
Nonstop1h 30mUnited Airlines
Wed 10/229:25 amORD - STL
Nonstop1h 24mUnited Airlines
Deal found 9/16$97
This American Airlines deal was found by Cheapflights users on 9/15. 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 10/237:16 amSTL - ORD
Nonstop1h 27mAmerican Airlines
Mon 10/2710:34 pmORD - STL
Nonstop1h 20mAmerican Airlines
Deal found 9/15$98
This United Airlines deal was found by Cheapflights users on 9/16. 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.
Thu 10/165:00 amSTL - ORD
Nonstop1h 30mUnited Airlines
Tue 11/112:21 pmORD - STL
Nonstop1h 26mUnited Airlines
Deal found 9/16$114
This Southwest deal was found by Cheapflights users on 9/16. 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 10/156:55 amSTL - ORD
1 stop5h 50mSouthwest
Wed 10/227:30 amORD - STL
1 stop7h 15mSouthwest
Deal found 9/16$117
This Southwest deal was found by Cheapflights users on 9/17. 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 10/141:30 pmSTL - ORD
1 stop9h 35mSouthwest
Tue 10/211:30 pmORD - STL
1 stop7h 15mSouthwest
Deal found 9/17$122
This United Airlines deal was found by Cheapflights users on 9/16. 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.
Fri 10/2412:25 pmSTL - ORD
Nonstop1h 25mUnited Airlines
Sat 11/81:00 pmORD - STL
Nonstop1h 25mUnited Airlines
Deal found 9/16$134
This Priceline deal was found by Cheapflights users on 9/15. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/294:00 pmSTL - ORD
1 stop8h 10mFrontier
Thu 10/25:10 amORD - STL
1 stop9h 54mFrontier
Deal found 9/15$143
This Priceline deal was found by Cheapflights users on 9/16. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/254:00 pmSTL - ORD
1 stop8h 10mFrontier
Mon 9/295:10 amORD - STL
1 stop9h 54mFrontier
Deal found 9/16$144
This Frontier deal was found by Cheapflights users on 9/15. 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 10/231:41 pmSTL - ORD
1 stop17h 53mFrontier
Mon 10/2710:51 amORD - STL
1 stop22h 16mFrontier
Deal found 9/15$145
This United Airlines deal was found by Cheapflights users on 9/15. 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 10/135:28 pmSTL - ORD
Nonstop1h 25mUnited Airlines
Mon 10/202:20 pmORD - STL
Nonstop1h 24mUnited Airlines
Deal found 9/15$146
This United Airlines deal was found by Cheapflights users on 9/15. 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 10/1512:25 pmSTL - ORD
Nonstop1h 25mUnited Airlines
Mon 10/202:20 pmORD - STL
Nonstop1h 24mUnited Airlines
Deal found 9/15$148

Cheapflights Fare Finder

 
Customize your flight search to find flights from St. Louis to O'Hare Intl 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 September 17, 2025.
Use the filters below to find and compare flights from St. Louis to Chicago O'Hare Intl Airport that are best for you.

Fly from

St. Louis

Fly to

O'Hare Intl

Route

Depart

Return

Price

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Wed 10/15

5:00 am-6:30 am

Nonstop1h 30m

Chicago O'Hare Intl

Wed 10/22

9:25 am-10:49 am

Nonstop1h 24m

$97

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Wed 10/15

5:00 am-6:30 am

Nonstop1h 30m

Chicago O'Hare Intl

Wed 10/15

1:03 pm-2:27 pm

Nonstop1h 24m

$97

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Wed 10/15

12:25 pm-1:50 pm

Nonstop1h 25m

Chicago O'Hare Intl

Thu 10/16

2:20 pm-3:44 pm

Nonstop1h 24m

$97

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Tue 10/14

6:30 am-8:00 am

Nonstop1h 30m

Chicago O'Hare Intl

Tue 10/21

9:25 am-10:49 am

Nonstop1h 24m

$97

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Wed 10/15

6:55 am-12:45 pm

1 stop5h 50m

Chicago O'Hare Intl

Wed 10/22

3:10 pm-10:05 pm

1 stop6h 55m

$117

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Tue 10/14

1:30 pm-11:05 pm

1 stop9h 35m

Chicago O'Hare Intl

Tue 10/21

1:30 pm-8:45 pm

1 stop7h 15m

$122

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Thu 11/20

8:25 am-12:15 pm

1 stop3h 50m

Chicago O'Hare Intl

Thu 11/20

1:45 pm-10:10 pm

1 stop8h 25m

$122

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Tue 10/7

9:20 am-10:50 am

Nonstop1h 30m

Chicago O'Hare Intl

Fri 10/10

11:01 am-12:28 pm

Nonstop1h 27m

$134

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Fri 10/24

12:25 pm-1:50 pm

Nonstop1h 25m

Chicago O'Hare Intl

Sat 11/8

1:00 pm-2:25 pm

Nonstop1h 25m

$134

St. LouisChicago

STL - ORD

STLORD

Lambert-St Louis

Mon 10/20

5:28 pm-6:53 pm

Nonstop1h 25m

Chicago O'Hare Intl

Fri 10/24

9:25 am-10:49 am

Nonstop1h 24m

$134

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/14

Showing 1-10 of 22 results
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The best insider tips for St. Louis to Chicago O'Hare Intl Airport 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 O'Hare Intl Airport trip
Airlines
Lufthansa

Lufthansa's Economy Flex offers preferred seating and same-day flight changes.


Lufthansa's Free Neighbor Seat allows extra space for a fee on long-haul flights.

Read more about Lufthansaby Blane Bachelor
United Airlines

Basic Economy on United allows no carry-on bags, only a personal item.


Prepay checked bag fees 24 hours before to save money on United flights.

Read more about United Airlinesby Harriet Baskas
Airports
STL

Security lines at STL are straightforward, averaging 5-10 minutes off-peak. Check real-time wait times online before heading to the airport.

Read more about STLby Taryn White
ORD

For a quick city trip from ORD, take the 'L' train. It's often faster than taxis due to Chicago traffic.

Read more about ORDby 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
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

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 O'Hare Intl

Have a flexible travel schedule? Discover the best time to fly to O'Hare Intl 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 O'Hare Intl Airport

How far ahead should I book a flight from St. Louis to Chicago O'Hare Intl Airport?

Use this chart to determine the optimal time to book a round-trip flight from St. Louis to O'Hare Intl. Price data was last updated on September 12, 2025.

To ensure you get the cheapest price possible for a flight from St. Louis to Chicago O'Hare Intl Airport, you should look to book at least 75 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

What is the cheapest month to book a flight from St. Louis to Chicago O'Hare Intl Airport?

Currently, August is the cheapest month in which you can book a flight from St. Louis to Chicago O'Hare Intl Airport (average of $245). Flying from St. Louis to Chicago O'Hare Intl Airport 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 ORD?

Find hourly flight availability from St. Louis to O'Hare Intl. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated September 17, 2025.

It’s typically best to fly out from St. Louis to Chicago O'Hare Intl Airport in the morning. Doing so could potentially save you 47% on the flight price compared to flying at noon, which is usually more expensive.

What is the cheapest day to fly from St. Louis to Chicago O'Hare Intl Airport?

Use this chart to determine the cheapest time to fly round-trip from St. Louis to O'Hare Intl. Price data was last updated on September 14, 2025.

Travelers seeking maximum savings on their St. Louis to Chicago O'Hare Intl Airport flight should consider departing on Friday 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.

Reviews of airlines servicing O'Hare Intl

Get insights into the airlines that provide service to O'Hare Intl. 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 O'Hare Intl. Reviews last updated September 17, 2025.
See what other customers who have flown with United Airlines and American Airlines from St. Louis to Chicago O'Hare Intl Airport have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
United Airlines
7.4
Good
8,926 reviews

Comfort

7.3

Entertainment

7.1

Food

6.6

Overall

7.4

Crew

8.1

Boarding

7.7

Reviews

1 / 20
2.0
Mediocre

Deb,Jan 2025

MKE - ORD

It was terrible! So much to say, but in a nutshell we used vouchers from United because our last trip with them was awful with many mishaps and errors made. Unfortunately, this trip was even worse!
United Airlines
7.4
Good
8,926 reviews
United Airlines
7.4
Good
8,926 reviews

Comfort

7.3

Entertainment

7.1

Food

6.6

Overall

7.4

Crew

8.1

Boarding

7.7

Reviews

1 / 20
2.0
Mediocre

Deb,Jan 2025

MKE - ORD

It was terrible! So much to say, but in a nutshell we used vouchers from United because our last trip with them was awful with many mishaps and errors made. Unfortunately, this trip was even worse!
American Airlines
7.2
Good
10,000 reviews
United Airlines
7.4
Good
8,926 reviews

Comfort

7.3

Entertainment

7.1

Food

6.6

Overall

7.4

Crew

8.1

Boarding

7.7

Reviews

1 / 20
2.0
Mediocre

Deb,Jan 2025

MKE - ORD

It was terrible! So much to say, but in a nutshell we used vouchers from United because our last trip with them was awful with many mishaps and errors made. Unfortunately, this trip was even worse!

Related info for your journey

Find useful and relevant information for your journey from St. Louis to O'Hare Intl. 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 O'Hare Intl?

    If you book a flight to Chicago O'Hare Intl 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 62 flights from Lambert-St Louis to Chicago O'Hare Intl per day from 3 different airlines.

  • How long is the flight from St. Louis to Chicago O'Hare Intl Airport?

    United Airlines and Southwest can get you from St. Louis to Chicago O'Hare Intl Airport in just under 1h 30m. Your travel time can differ by up to 4h 20m. The distance between St. Louis and Chicago O'Hare Intl Airport is about 258 mi. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the cheapest airlines flying from St. Louis to Chicago O'Hare Intl Airport round-trip?

    Flying on American Airlines is currently your cheapest option to Chicago O'Hare Intl Airport, with prices starting at $117. Additional round-trip tickets that might be worth considering are offered by Southern / Mokulele and United Airlines, with the lowest prices starting at $140 and $143, respectively. American Airlines is 58% cheaper than the average price of flights available within the next 90 days to this destination.

  • What are the most reliable airlines from St. Louis to Chicago O'Hare Intl Airport?

    Before booking your flight to Chicago O'Hare Intl Airport from St. Louis, check out the most reliable airlines to get you to your destination on time: Cathay Pacific (89%), Japan Airlines (80%), Copa Airlines( 78%).

  • What are the cheapest flights from St. Louis to Chicago O'Hare Intl Airport?

    The cheapest flight price from St. Louis to Chicago O'Hare Intl Airport is $75. On average you can expect to pay $706. The most popular route, (Lambert-St Louis - Chicago O'Hare Intl), can usually be booked for $97.

  • Can I find deals for flights from St. Louis to O'Hare Intl that include hotel bookings?

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

  • How can I find direct flights from St. Louis to O'Hare Intl?

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

  • Can I find deals for business class flights from St. Louis to O'Hare Intl?

    Yes. Cheapflights offers flight deals from St. Louis to O'Hare Intl 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 O'Hare Intl Airport?

    Currently, August is the cheapest month in which you can book a flight from St. Louis to Chicago O'Hare Intl Airport (average of $245). Flying from St. Louis to Chicago O'Hare Intl Airport 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 O'Hare Intl Airport?

Book flights to Chicago O'Hare Intl Airport if you plan to visit one of these locations
Schaumburg
Rosemont
Skokie
Gurnee
Hoffman Estates
Des Plaines
Elgin
Arlington Heights
Orland Park
Beloit
Racine
Rockford
Oak Brook
Elk Grove Village
Downers Grove
Naperville
Evanston
Merrillville
Bridgeview
Warrenville

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Top 3 airlines flying from St. Louis to O'Hare Intl

Discover the top 3 airlines that operate flights from St. Louis to O'Hare Intl. 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 September 17, 2025.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$117Average$277FlexibilityNo cancel feeOn-time71%
Southern / MokuleleCheapest$140Average$217FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$143Average$314FlexibilityNo cancel feeOn-time69%

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