Cheap Flights from Denver to St Louis

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Flight deals from Denver to St Louis

Looking for a cheap last-minute deal or the best return flight from Denver to St Louis? Find the lowest prices on one-way and return tickets right here.

Find the cheapest month to fly from Denver to St Louis

We’re always keeping an eye on fares, so you can find the best one in seconds. It looks like Denver to St Louis flights are currently cheapest in October.

Direct flights from Denver to St Louis

Denver to St Louis: Alternative routes

Compare routes from Denver to St Louis below. You may find an airport to fly into that's cheaper, faster, or easier than St Louis.

Denver to St Louis: Flight information

The things to know before you go.
Cheapest flight foundRs11,985
Cheapest month to flyOctober
Average flight time2 hrs, 5 mins
Most popular airlineSouthwest Airlines
Average flights per week86

Finding cheap flights from Denver to St Louis: Frequently asked questions

The best price we found for a return flight from Denver to St Louis is Rs22,857. This is an estimate based on information collected from different airlines and travel providers over the last 4 days and is subject to change and availability.
2 hours and 5 minutes is the average flight time from Denver to St Louis.
Southwest Airlines, United and Air Canada fly direct from Denver to St Louis.
As of September 2025, there are 86 flights per week flying from Denver to St Louis.
The cheapest month to fly from Denver to St Louis is usually October.
After crunching the numbers on our flight calendar, we found that it is currently cheapest to fly from Denver to St Louis Airport on Sunday, 19 October 2025.
Yes – the average flight time is 2 hours and 5 minutes.
We show every price from over 1,200 airlines and travel agents, comparing them all so you don’t have to. If you know you want to fly to St Louis but you’re not ready to book, set up a Price Alert. We’ll track prices for you, and let you know when they rise or fall.
We crunched all the numbers in our flight calendar and it looks like the cheapest time to book a flight to St Louis is around 40 days in advance, so don’t leave your flight to the last minute.
The cheapest airline that flies to St Louis is Frontier Airlines .

Travelling from Denver to Lambert-St. Louis International Airport (STL): What you need to know

  • Put your plans into motion at Denver International Airport (DEN), the main airport in Denver. Look for flights from Denver to Lambert-St. Louis International Airport (STL) that take off from this base.

  • 2 hours 5 minutes is the average journey time for a direct Denver to Lambert-St. Louis International Airport flight.

  • St Louis is one hour ahead of Denver. Lambert-St. Louis International Airport is located in St Louis, which operates on the UTC-5 timezone.

  • With 53 direct weekly flights between the two airports, Denver International Airport (DEN) to Lambert-St. Louis International Airport (STL) is the most popular route. Southwest Airlines operates the earliest flight at 5am. If you're eager to get more out of your day before taking off, the last flight from DEN to STL is with Southwest Airlines at 10:25pm.

  • Arrive at the airport on time so you don't miss your flight from Denver to STL. Be there at least two hours ahead for international flights and an hour early for domestic departures to avoid sprinting to your gate.

  • Delays at security and check-in are likely if you're flying during high season, so give yourself some extra breathing room. The recommendation for peak periods? Get there up to four hours early for international flights and at least two hours for domestic departures.

Airports in Denver

Denver International Airport (DEN)

  • Denver International Airport (DEN) provides a hassle-free way to reach your destination. Nonstop flights from Denver to Lambert-St. Louis International Airport (STL) depart from this terminal.

  • Popular airlines that operate direct flights from Denver to Lambert-St. Louis International Airport departing DEN include:

  • Southwest Airlines ranks first in bookings for flights from DEN to STL.

  • The carrier with the most reliable on-time arrival rate on this route is United Airlines.

  • Located around 40 kilometres from the centre of Denver, DEN can be reached in about 35 minutes by car (depending on traffic). The journey on public transport will take roughly 1 hour 30 minutes.

  • Spending the night in a hotel can take the hassle out of getting to the airport on time. If you're searching for somewhere to stay before your flight from Denver to Lambert-St. Louis International Airport, consider Baymont by Wyndham Denver International Airport. It's a quick drive from Denver International Airport.

  • 80.23% of flights leaving Denver International Airport land at their destination according to schedule. Given its strong on-time performance, you're unlikely to be delayed when flying out of DEN.

  • DEN is located at 8500 Pena Boulevard.

About Lambert-St. Louis International Airport (STL)

Getting from Lambert-St. Louis International Airport (STL) to central St Louis

  • Lambert-St. Louis International Airport is around 16 kilometres from central St Louis. How long it takes to get there by cab or car hire will depend on the time of day. Do some research before your trip.

  • It takes around 35 minutes if you're travelling on public transport.

How to find the cheapest flights from Denver to Lambert-St. Louis International Airport (STL)

  • The cheapest price we've found for a one-way ticket from Denver to Lambert-St. Louis International Airport is Rs11,985. For a return flight on this route, the best price is Rs22,857. Depending on how early you book and the availability, these fares can change.

  • To pick up cheap flights from Denver to STL, book in advance. Airlines generally offer their most competitively priced fares when flights are first released.

  • The 'Whole month' search tool shows you the cheapest Denver to Lambert-St. Louis International Airport tickets across every month. It's a great way to find a bargain if your travel plans are flexible.

  • You don't need to search every day to find out if fares have dropped when you create a Price Alert. We'll let you know as soon as a new deal shows up on flight tickets from Denver to STL.

  • Chase down a great fare on a flight from Denver to Lambert-St. Louis International Airport with the help of the filters. Pick your ideal departure and arrival times, airlines and number of stops. You can also sort your results by 'Cheapest,' 'Fastest' or 'Best.'

The best time to fly from Denver to Lambert-St. Louis International Airport (STL)

  • It's time to decide your travel dates for your flight from Denver to Lambert-St. Louis International Airport (STL). July is the peak month for travel to St Louis. If you like your getaways a little more chill, head there in April.

  • Lock in a Denver to STL flight ticket departing in July if you want to explore the city during its warmest month. Expect temperatures in St Louis to range from 17ºC to 33ºC.

  • January sees temperatures of between -8ºC and 7ºC. Look for cheap tickets from Denver to Lambert-St. Louis International Airport around that time if you like cooler conditions.

More about St Louis

Explore more of the United States

  • St Louis has plenty going for it, but there are so many other corners of the United States just waiting to be discovered. Around 257 kilometres east of St Louis, a trip to Evansville will fill your itinerary to the brim. Start with attractions like Mesker Park Zoo, Riverfront Park and Evansville Zoological Society.

  • Columbia is another favourite destination in the United States and is around 177 kilometres west of St Louis. No journey is complete without experiencing Sentinel Park, Museum of Art and Archaeology and Bur Oak Brewing Company.

Prices shown on this page are estimated lowest prices only. Found in the last 45 days.