Cheap Flights from St. Louis (STL) to Denver (APA)

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Find available prices by choosing your travel dates.
Flights from St. Louis (STL) to Denver (APA)
Origin airport
Lambert-St. Louis Intl.
Destination airport
Centennial
Distance
777 mi

St. Louis to Denver Flights

The cheapest times to fly from St. Louis to Denver

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

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

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

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 Denver 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 St. Louis to Denver 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 Denver 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 Centennial Airport (APA) cost?
Discover the latest flight deals from STL to APA by entering your preferred travel dates and searching on Expedia. Easily compare prices by departure date if you have flexibility with your schedule and use handy filters to explore prices for your preferred journey. As a member of One Key™, our free loyalty program, you can use Price Tracking to watch fares and receive notifications if prices go up or down.
What is the cheapest month to fly from STL to APA?
The cheapest flights from STL to APA are usually during off-peak season, when demand is lower. To save money, avoid flying during public holidays, school breaks and major local events.
What is the cheapest airline that flies from STL to APA?
Use the filter tool on Expedia to compare airlines and find the cheapest carrier that’ll take you from STL to APA. Sort your results by “Price (lowest to highest)” to snap up a great deal.
How many flights per day from Lambert-St. Louis Intl. Airport (STL) to Centennial Airport (APA)?
There aren’t any daily nonstop flights available from Lambert-St. Louis Intl. Airport (STL) to Centennial Airport (APA). But you can opt for flights with layovers. Filter your search on Expedia to include one or two stops, and you’ll be cruising above the clouds in no time at all.
What day of the week has the most flights from STL to APA?
You’ll typically find Tuesday the quietest day for flights, while Fridays are often the busiest.* However this can change from season to season and during public holidays or peak travel times.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Lambert-St. Louis Intl. Airport (STL) to Centennial Airport (APA)?
To arrive at Centennial Airport (APA) on time, opt for a flight that leaves Lambert-St. Louis Intl. Airport (STL) 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 Denver from Lambert-St. Louis Intl. Airport (STL)?
Check out your flight options from Lambert-St. Louis Intl. Airport (STL) to Denver Intl. Airport (DEN). This is the only airport in Denver you can fly into if you’re taking a direct flight.
Is it cheaper to buy a plane ticket from Lambert-St. Louis Intl. Airport (STL) to Centennial Airport (APA) last-minute?
Booking your flight from STL to APA just before your trip is generally more expensive. However, if there’s some wiggle room with your itinerary, you could snag a cheap last-minute fare.
Is it cheaper to book a STL to APA flight and hotel package?
Compared with arranging hotels and flights separately, booking a STL to APA flight and hotel package with Expedia could lead to significant savings. Better yet, having everything in one easy place takes the hassle out of planning your trip. Just secure your flights and choose from our extensive range of stays, then customize your trip with other add-ons like tours, car rentals and activities.
Can I cancel or change the date of my flight from Lambert-St. Louis Intl. Airport (STL) to Centennial Airport (APA)?
In most instances, you’re able to reschedule or cancel your STL to APA flight. However, additional charges may apply, especially if you made your booking more than 24 hours ago. Double-check your itinerary for the airline’s guidelines and fees on flight changes, or if you’d like further details, visit our Customer Service portal.

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*Available to One Key members.