Flights from Denver (DEN) to St. Louis (STL)

Fly east to the Gateway to the West when you travel from Denver to St. Louis with Southwest Airlines®! Southwest® has flights from Denver International Airport to Lambert-St. Louis International Airport that that will take you on a trip of a lifetime. Find your flight to St. Louis with Southwest and book with confidence. If your upcoming excursion has flexible dates, search for flights with our Low Fare Calendar and discover the lowest fares we’ve got. Don't forget to explore Southwest Vacations® to find package deals on flights, hotels, rental cars, and more.

Check out Denver to St. Louis flights and book yours now!


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Denver, CO to St. Louis, MO

departing on 8/28

one-way starting at*

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*Restrictions and exclusions apply. Seats and dates are limited. Select markets. 120 travel days available.

Check out Denver to St. Louis flights and book yours now!

Flight details

Average flight time: 2 hours 0 minutes

Departing from: Denver International Airport (DEN)

Arriving at: Lambert-St. Louis International Airport (STL)


Route information


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Based on DOT published scheduled average flights Monday-Friday between 8/4/2020 and 1/4/2021, as of 8/4/2020.

Explore St. Louis

There’s so much to see in St. Louis, that it’s no wonder they call Missouri the Show-Me State! First and foremost, is St. Louis’ most famous landmark, the Gateway Arch! Built as a monument to the country's westward expansion, the Gateway Arch is an engineering marvel that spans 630 feet from leg to leg while rising 630 feet into the air! While you’re checking out the arch, you can learn more about it at the Museum of Westward Expansion and the Gateway Arch Visitors Center. The park surrounding the arch features miles of bike paths, and you can even hitch a ride to the top to take in some truly incredible aerial views of the city.

If you like the park surrounding Gateway Arch, you’ll like Forest Park even better. Almost double the size of New York’s famous Central Park, this aptly named urban park truly is sized more like a forest than a park, with a whopping 1,371 acres of meadows, trees, ponds, lakes, streams, golf courses, tennis courts, sculptures, wetlands, and wildlife. Originally built in 1876, Forest Park was the home of the 1904 World’s Fair and remains steeped in St. Louis history to this day. Known as the Heart of St. Louis, Forest Park is also home to great attractions like the St. Louis Zoo, the Saint Louis Art Museum, the St. Louis Science Center, and the Missouri History Museum.

Travel tips


Infancy policy

One child over 14 days and under two (2) years of age, not occupying a seat, may be carried free of charge when traveling with an adult (12 years of age or older). Learn more.


Pet policy

Customers flying with a pet are subject to a pet fare. To learn more about traveling with your furry friend, explore the Southwest pet policy.


Unaccompanied minor

Minors under the age of 18 are not permitted to fly unaccompanied on international flights or any itinerary that includes an international flight. Learn more.


Bags fly free

Start packing! Every ticketed Customer’s first two checked bags are free. Learn more.


The Southwest travel experience

At Southwest, we know that planning a memorable trip from Denver to St. Louis takes a lot more than just scoring some cheap flights from Denver International Airport to Lambert-St. Louis International Airport. From booking to boarding, we offer services and perks that make your travel experience as smooth as possible. Find out more about the Southwest Experience before you book your Denver to St. Louis flight.

It’s simple and fun to fly with Southwest, no matter which of our destinations you choose. And when you search for your next flight to St. Louis, you know you won’t be hassled by hidden fees—we offer low fares and, as always, bags fly free. That’s our Transfarency® promise. Enroll in our Click 'N Save® emails and stay in the know about our latest flight deals. Looking for tours, activities, and more hidden gems? Check out Southwest Airlines Experiences and earn Rapid Rewards points when you fly.

1First and second checked bags. Weight and size limits apply.

2Fare difference may apply.