$39 Cheap Flights from St. Louis (STL) to Chicago (ORD)

View $39 flight on Thu, Aug 7, 2025Opens in a new window

Popular airlines from St. Louis Lambert Intl. Airport (STL) to Chicago O'Hare Intl. Airport (ORD)

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Find available prices by choosing your travel dates.

Cheap Flights from St. Louis to Chicago (STL-ORD)

Prices were available within the past 7 days and start at $39 for one-way flights and $77 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

United
Mon, Sep 1 - Wed, Sep 3
STL
St. Louis
ORD
Chicago
$77 Roundtrip, found 1 hour ago
$77
Roundtrip
found 1 hour ago
Select United flight, departing Mon, Sep 1 from St. Louis to Chicago, returning Wed, Sep 3, priced at $77 found 1 hour ago
United
Mon, Jun 9 - Mon, Jun 16
STL
St. Louis
ORD
Chicago
$80 Roundtrip, found 2 hours ago
$80
Roundtrip
found 2 hours ago
Select United flight, departing Mon, Jun 9 from St. Louis to Chicago, returning Mon, Jun 16, priced at $80 found 2 hours ago
United
Mon, Sep 1 - Wed, Sep 3
STL
St. Louis
ORD
Chicago
$84 Roundtrip, found 1 hour ago
$84
Roundtrip
found 1 hour ago
Select United flight, departing Mon, Sep 1 from St. Louis to Chicago, returning Wed, Sep 3, priced at $84 found 1 hour ago
Southwest Airlines
Mon, Jun 9 - Tue, Jun 10
STL
St. Louis
ORD
Chicago
$87 Roundtrip, found 1 hour ago
$87
Roundtrip
found 1 hour ago
Select Southwest Airlines flight, departing Mon, Jun 9 from St. Louis to Chicago, returning Tue, Jun 10, priced at $87 found 1 hour ago
Southwest Airlines
Mon, Jun 9 - Mon, Jun 16
STL
St. Louis
ORD
Chicago
$89 Roundtrip, found 2 hours ago
$89
Roundtrip
found 2 hours ago
Select Southwest Airlines flight, departing Mon, Jun 9 from St. Louis to Chicago, returning Mon, Jun 16, priced at $89 found 2 hours ago
Southwest Airlines
Mon, Aug 25 - Wed, Sep 3
STL
St. Louis
ORD
Chicago
$93 Roundtrip, found 5 hours ago
$93
Roundtrip
found 5 hours ago
Select Southwest Airlines flight, departing Mon, Aug 25 from St. Louis to Chicago, returning Wed, Sep 3, priced at $93 found 5 hours ago
Southwest Airlines
Tue, Sep 23 - Wed, Sep 24
STL
St. Louis
ORD
Chicago
$94 Roundtrip, found 2 hours ago
$94
Roundtrip
found 2 hours ago
Select Southwest Airlines flight, departing Tue, Sep 23 from St. Louis to Chicago, returning Wed, Sep 24, priced at $94 found 2 hours ago
American Airlines
Sat, May 17 - Tue, Jun 3
STL
St. Louis
ORD
Chicago
$116 Roundtrip, just found
$116
Roundtrip
just found
Select American Airlines flight, departing Sat, May 17 from St. Louis to Chicago, returning Tue, Jun 3, priced at $116 just found
Southern Airways Express
Tue, May 13 - Fri, May 23
STL
St. Louis
ORD
Chicago
$140 Roundtrip, found 1 day ago
$140
Roundtrip
found 1 day ago
Select Southern Airways Express flight, departing Tue, May 13 from St. Louis to Chicago, returning Fri, May 23, priced at $140 found 1 day ago
Frontier Airlines
Wed, Jun 11 - Sat, Jun 14
STL
St. Louis
ORD
Chicago
$172 Roundtrip, found 1 day ago
$172
Roundtrip
found 1 day ago
Select Frontier Airlines flight, departing Wed, Jun 11 from St. Louis to Chicago, returning Sat, Jun 14, priced at $172 found 1 day ago
Flights from St. Louis (STL) to Chicago (ORD)
Origin airport
Lambert-St. Louis Intl.
Destination airport
O'Hare Intl.
Airlines serving
Alaska Airlines, American Airlines, Delta, Frontier Airlines, Southern Airways Express, Southwest Airlines, United
Roundtrip price
$77
Distance
258 mi

St. Louis to Chicago Flights

The cheapest times to fly from St. Louis to Chicago

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from St. Louis to Chicago are during the month of September. You can find some of the cheapest flights from St. Louis to Chicago with Expedia's search tool and vast selection of airlines.

The best time to book a flight from St. Louis to Chicago

Sunday is one of the best days to book for cheap flights from St. Louis to Chicago: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

How to find cheap round-trip tickets from St. Louis to Chicago

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from St. Louis to Chicago in 2025. You can also book with separate airlines for your outbound and return journeys, from $39 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap St. Louis to Chicago flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

You could also save big by booking one of Expedia's vacation packages. Bundling together your St. Louis to Chicago airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

*Terms apply.

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

Frequently asked questions

How much does a flight from Lambert-St. Louis Intl. Airport (STL) to O'Hare Intl. Airport (ORD) cost?
Cheap round-trip flights from Lambert-St. Louis Intl. Airport (STL) to O’Hare Intl. Airport (ORD) start from $97. This information is based on the cheapest price found on Expedia for this return journey departing within the next three months. This airfare is for a American Airlines flight leaving STL on May 15 2025 and touching down at ORD. The price was last updated on April 21 2025 and has not changed since.
What is the cheapest month to fly from STL to ORD?
The cheapest flights from STL to ORD are usually during off-peak season, when demand is lower. To save money, avoid flying during public holidays, school breaks and major local events.
Which airlines fly direct from Lambert-St. Louis Intl. Airport (STL) to O'Hare Intl. Airport (ORD)?
When heading out of Lambert-St. Louis Intl. Airport (STL), you can get on a nonstop flight to O’Hare Intl. Airport (ORD) with United Airlines.
What is the cheapest airline that flies from STL to ORD?
Currently, the cheapest airline operating one-way flights from STL to ORD is United. You can book a seat on this route from $49. This fare is based on the lowest price found on Expedia departing within the next three months. The flight takes off from STL on July 2 2025. Prices were last updated on April 21 2025 and have not changed since.
How many flights per day from Lambert-St. Louis Intl. Airport (STL) to O'Hare Intl. Airport (ORD)?
When flying out of Lambert-St. Louis Intl. Airport (STL), you can take your pick from an average of 11 daily direct flights to O’Hare Intl. Airport (ORD).
What are the most popular departure times for flights from Lambert-St. Louis Intl. Airport (STL) to O'Hare Intl. Airport (ORD)?
More travelers fly between STL and ORD at 11 AM than at any other time. Prefer a quieter experience? Consider flying outside peak hours and you’re likely to save on your fare as well.
What day of the week has the most flights from STL to ORD?
If you travel on a Saturday, you’ll get the widest range of options for flights from Lambert-St. Louis Intl. Airport (STL) to O’Hare Intl. Airport (ORD).
What is the earliest flight from Lambert-St. Louis Intl. Airport (STL) to O'Hare Intl. Airport (ORD)?
Hop on the earliest flight at around 5:40AM UTC-6, departing from Lambert-St. Louis Intl. Airport (STL). You’ll be traveling for approximately 1h 28m, coming in to land at O’Hare Intl. Airport (ORD) at approximately 7:08AM UTC-6.
How long does it take to fly from Lambert-St. Louis Intl. Airport (STL) to O'Hare Intl. Airport (ORD)?
It takes approximately 1 hour and 31 minutes to cover the 260 mi from STL to ORD.
What is the best time to fly from Lambert-St. Louis Intl. Airport (STL) to O'Hare Intl. Airport (ORD)?
Opt for a flight from Lambert-St. Louis Intl. Airport (STL) to O’Hare Intl. Airport (ORD) that takes off before 3 PM to reduce the risk of cancellations and delays. Departures after this time are on average 22% more likely to be canceled.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG’s global flight data platform.
What airports do you fly into for Chicago from Lambert-St. Louis Intl. Airport (STL)?
You can land at O’Hare Intl. Airport (ORD) or Midway Intl. Airport (MDW) when traveling to Chicago on a direct flight from Lambert-St. Louis Intl. Airport (STL).
Is it cheaper to buy a plane ticket from Lambert-St. Louis Intl. Airport (STL) to O'Hare Intl. Airport (ORD) last-minute?
Waiting until just before your trip to book a flight from STL to ORD often results in higher prices. While you may come across some last-minute offers, they aren’t always guaranteed. Allow some flexibility in your schedule for the best chance of snagging a bargain.
Is it cheaper to book a STL to ORD flight and hotel package?
You’ll generally save money by securing a STL to ORD flight and hotel package compared to booking separately. In fact, you could save hundreds of dollars by bundling with Expedia. And it’s easy to manage everything in one convenient place. After selecting your ideal accommodations and flights, consider adding extras such as tours, activities and car rentals.
Can I cancel or change the date of my flight from Lambert-St. Louis Intl. Airport (STL) to O'Hare Intl. Airport (ORD)?
In most cases, you can reschedule or cancel your STL to ORD flight. However, there may be additional charges, especially if you made your booking over 24 hours ago. Double-check your itinerary for the airline’s fees and guidelines on flight changes, or if you need further details, visit our Customer Service portal.

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*Available to One Key members.