Cheap Flights from Chicago (ORD) to St. Louis (CPS)

Popular airlines from Chicago O'Hare Intl. Airport (ORD) to St. Louis, MO (CPS-St. Louis Downtown)

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Alternative airports near St. Louis

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to Lambert-St. Louis Intl. STL. Cheapest option available. Average driving time to city center is 20 minutes. Flights from $227
STL
Lambert-St. Louis Intl.
Cheapest
Average driving time to city center20 min
Flights from $227
Flights from Chicago (ORD) to St. Louis (CPS)
Origin airport
O'Hare Intl.
Destination airport
St. Louis Downtown
Distance
263 mi

Chicago to St. Louis Flights

The cheapest times to fly from Chicago to St. Louis

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 Chicago to St. Louis are during the month of . You can find some of the cheapest flights from Chicago to St. Louis with Expedia's search tool and vast selection of airlines.

 

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

Sunday is one of the best days to book for cheap flights from Chicago to St. Louis: 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 Chicago to St. Louis

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 Chicago to St. Louis in 2025. You can also book with separate airlines for your outbound and return journeys, from 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 Chicago to St. Louis 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 Chicago to St. Louis 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 O'Hare Intl. Airport (ORD) to St. Louis Downtown Airport (CPS) cost?
Grab a cheap one-way flight or cheap return flight from O'Hare Intl. Airport (ORD) to St. Louis Downtown Airport (CPS) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to see our cheapest flight offers on this route.
What is the cheapest month to fly from O'Hare Intl. Airport (ORD) to St. Louis Downtown Airport (CPS)?
Traveling in may help you find better deals, as it's the cheapest month for flights between ORD and CPS. You'll usually find the lowest fares during the off-season.
What is the cheapest airline that flies from O'Hare Intl. Airport (ORD) to St. Louis Downtown Airport (CPS)?
To find the cheapest airline that'll fly you from ORD to CPS, use Expedia's filter tool. Tailor your search based on what matters most to you, such as preferred carriers and cabin class. You can then sort your results by "Price (lowest to highest)" to see the cheapest flights first.
How many flights per day from O'Hare Intl. Airport (ORD) to St. Louis Downtown Airport (CPS)?
You'll need to take a flight with a layover when traveling from O'Hare Intl. Airport (ORD) to St. Louis Downtown Airport (CPS). Direct flights don't operate daily on this route. However, simply filter your search to include one or two stops to find an option that works for you.
What day of the week has the most flights from ORD to CPS?
Friday is generally the busiest day for flights, while Tuesday is often the quietest.* Keep in mind that flight schedules can change depending on a number of factors, including the time of year and airline.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from O'Hare Intl. Airport (ORD) to St. Louis Downtown Airport (CPS)?
To arrive at St. Louis Downtown Airport (CPS) on schedule, choose a flight that takes off from O'Hare Intl. Airport (ORD) before 3 PM. The chance of cancellations is 22% higher, on average, for departures after this time.**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 East St. Louis from O'Hare Intl. Airport (ORD)?
If you've booked a direct flight from O'Hare Intl. Airport (ORD) to East St. Louis, Lambert-St. Louis Intl. Airport (STL) is the only airport you can touch down at.
Is it cheaper to buy a plane ticket from O'Hare Intl. Airport (ORD) to St. Louis Downtown Airport (CPS) last-minute?
Waiting until just before your departure to book your flight from ORD to CPS often results in higher prices. While you might find some last-minute discounts, there's no guarantee. Keep your travel schedule open to boost your chances of scoring a bargain.
Is it cheaper to book an ORD to CPS flight and hotel package?
Compared with arranging hotels and flights separately, booking an ORD to CPS flight and hotel package with Expedia could result in significant savings. Better yet, having everything in one convenient place takes the hassle out of planning your trip. Just pick your flights and select from our wide range of hotels, then personalize your trip with extras like tours, car rentals and activities.
Can I cancel or change the date of my flight from O'Hare Intl. Airport (ORD) to St. Louis Downtown Airport (CPS)?
Typically, it's possible to cancel or reschedule your ORD to CPS flight. However, if it's been more than 24 hours since booking, additional fees may apply. Refer to your airline's policies in your itinerary to see what changes are possible and whether any costs are involved. You'll also find further details on our Customer Service portal.

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*Available to One Key members.