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Cheap Flights from St Louis (STL) to Denver (DENA)

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Flight deals from St Louis to Denver

Looking for a cheap last-minute deal or the best return flight from St Louis to Denver? Find the lowest prices on one-way and return tickets right here.
Denver.£43 per passenger.Departing Wed, 4 Feb, returning Sat, 7 Feb.Return flight with Frontier Airlines.Outbound direct flight with Frontier Airlines departs from St Louis on Wed, 4 Feb, arriving in Denver International.Inbound direct flight with Frontier Airlines departs from Denver International on Sat, 7 Feb, arriving in St Louis.Price includes taxes and charges.From £43, select.
Denver.£46 per passenger.Departing Sat, 24 Jan, returning Sat, 31 Jan.Return flight with Frontier Airlines.Outbound direct flight with Frontier Airlines departs from St Louis on Sat, 24 Jan, arriving in Denver International.Inbound direct flight with Frontier Airlines departs from Denver International on Sat, 31 Jan, arriving in St Louis.Price includes taxes and charges.From £46, select.
Denver.£49 per passenger.Departing Sat, 31 Jan, returning Mon, 2 Feb.Return flight with Frontier Airlines.Outbound direct flight with Frontier Airlines departs from St Louis on Sat, 31 Jan, arriving in Denver International.Inbound direct flight with Frontier Airlines departs from Denver International on Mon, 2 Feb, arriving in St Louis.Price includes taxes and charges.From £49, select.
Denver.£65 per passenger.Departing Mon, 23 Feb, returning Mon, 2 Mar.Return flight with Frontier Airlines.Outbound direct flight with Frontier Airlines departs from St Louis on Mon, 23 Feb, arriving in Denver International.Inbound direct flight with Frontier Airlines departs from Denver International on Mon, 2 Mar, arriving in St Louis.Price includes taxes and charges.From £65, select.
Denver.£70 per passenger.Departing Wed, 4 Mar, returning Wed, 11 Mar.Return flight with Frontier Airlines.Outbound direct flight with Frontier Airlines departs from St Louis on Wed, 4 Mar, arriving in Denver International.Inbound direct flight with Frontier Airlines departs from Denver International on Wed, 11 Mar, arriving in St Louis.Price includes taxes and charges.From £70, select.
Denver.£139 per passenger.Departing Wed, 8 Apr, returning Sun, 12 Apr.Return flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from St Louis on Wed, 8 Apr, arriving in Denver International.Inbound indirect flight with Frontier Airlines, departs from Denver International on Sun, 12 Apr, arriving in St Louis.Price includes taxes and charges.From £139, select.
Denver.£149 per passenger.Departing Tue, 24 Mar, returning Sun, 12 Apr.Return flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from St Louis on Tue, 24 Mar, arriving in Denver International.Inbound indirect flight with Frontier Airlines, departs from Denver International on Sun, 12 Apr, arriving in St Louis.Price includes taxes and charges.From £149, select.
Denver.£160 per passenger.Departing Mon, 30 Mar, returning Mon, 6 Apr.Return flight with Frontier Airlines.Outbound direct flight with Frontier Airlines departs from St Louis on Mon, 30 Mar, arriving in Denver International.Inbound direct flight with Frontier Airlines departs from Denver International on Mon, 6 Apr, arriving in St Louis.Price includes taxes and charges.From £160, select.

Find the cheapest month to fly from St Louis to Denver

We’re always keeping an eye on fares, so you can find the best one in seconds. It looks like St Louis to Denver flights are currently cheapest in February.
Jan
from £46
Feb
from £43
Mar
from £70
Apr
from £139
May
from £243
Jun
from £243
Jul
from £243
Aug
from £243
Sep
from £243
Oct
from £313
Nov
from £283
Dec
Find prices

Direct flights from St Louis to Denver

Alternative St Louis to Denver routes

Looking for the cheapest, fastest or easiest route from St Louis to Denver? You could fly into the following airports instead.

St Louis to Denver: Flight information

The things to know before you go.
Cheapest flight found£43
Cheapest month to flyFebruary
Average flight time2 hrs, 26 mins
Most popular airlineSouthwest Airlines
Average flights per week110

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

There are 4 airports in Denver: Denver Arapahoe Co, Broomfield, Denver International, and Northern Colorado Regional.
The best price we found for a return flight from St Louis to Denver is £43. 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 26 minutes is the average flight time from St Louis to Denver.
Southwest Airlines, United and Air Canada fly direct from St Louis to Denver.
As of January 2026, there are 105 flights per week flying from St Louis to Denver.
The cheapest month to fly from St Louis to Denver is usually February.
If you're flying from St Louis Airport, the cheapest airport near Denver is Denver International – which is 18.6 miles away from the centre of Denver. We've found flights into this airport from £43.
After crunching the numbers on our flight calendar, we found that it's currently cheapest to fly from St Louis Airport to Denver on Wednesday, 4 February 2026.
Yes – the average flight time is 2 hours and 26 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 Denver 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 Denver is around 40 days in advance, so don’t leave your flight to the last minute.
In January, the average temperature is usually around -1°C. July is typically the warmest month in Denver, when it usually averages around 31°C. You can expect the least rain in January. The coldest month is December, with temperatures averaging -6°C. The rainiest month is July.
Currently, Frontier Airlines offers the cheapest flight tickets to Denver.

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

  • Approximately 2 hours 5 minutes is how long you'll be travelling on a direct flight from Lambert-St. Louis International Airport to Denver.

  • The timezone in Denver is UTC-6. The city is one hour behind St Louis, where Lambert-St. Louis International Airport is located.

  • Lambert-St. Louis International Airport (STL) to Denver International Airport (DEN) is the most popular route, with 53 weekly departures to pick from. If you have things to do before leaving, the last flight from STL to DEN is with Southwest Airlines at 22:45. Go for the first departure with United Airlines at 05:15 if you want to get on your way earlier.

  • For stress-free travel, arrive at the airport two hours ahead of international flights and an hour before domestic departures. This ensures you have enough time to board your STL to Denver flight.

  • Taking off during a peak time like a bank holiday? Expect longer queues at check-in and security. To play it safe, arrive up to four hours before international flights and two hours before domestic departures.

  • You can book a direct Lambert-St. Louis International Airport to Denver ticket. Begin your trip at STL and arrive at Denver International Airport (DEN).

  • Well-known carriers that offer direct flights from Lambert-St. Louis International Airport to Denver include:

  • Located around 10 miles from central St Louis, STL can be reached in about 20 minutes by car. The journey on public transport will take roughly 35 minutes.

  • Catching an early flight from Lambert-St. Louis International Airport to Denver? Avoid the stress of rushing to the airport (and enjoy a little extra shut-eye) by choosing one of these hotels near STL:

  • 78.04% of flights that leave from Lambert-St. Louis International Airport make it to their destination on time.

  • STL's address is 10701 Lambert International Blvd..

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

  • The best price we've found for a one-way Lambert-St. Louis International Airport to Denver flight is £21. The cheapest price for a return flight is £43. Remember fares may change due to availability at the time of booking.

  • To snag cheap flights from STL to Denver, book your journey one month ahead of your departure date.

  • The best month for scoring cheap Lambert-St. Louis International Airport to Denver tickets is May. Use the 'Whole month' tool to compare all available prices, then select the dates offering the lowest fares.

  • Snapping up a cheap flight from STL to Denver couldn't be easier with Price Alerts. All you need to do is set up one of these automatic notifications and we'll notify you as soon as a cheaper option becomes available.

  • Select your ideal departure and arrival times, airlines and number of stops with our filters. Then, sort the results for your flight from Lambert-St. Louis International Airport to Denver by 'Best,' 'Cheapest' or 'Fastest.'

Airports in Denver

Denver International Airport (DEN)

  • Denver International Airport (DEN) is around 25 miles from central Denver. If you're getting a cab or a ride-share, the drive will take roughly 35 minutes.

  • If you're travelling on public transport, expect a journey time of around 1 hour 30 minutes.

  • Once your flight from Lambert-St. Louis International Airport to Denver has touched down, kick back and relax at a nearby hotel. Baymont by Wyndham Denver International Airport is a comfortable option that's a quick drive from DEN.

  • Pick up a Denver International Airport rental car and discover Denver and beyond with your own set of wheels. Routes Car Rentals, Dollar and Budget are leading providers you can book with here.

  • Lock in the best possible rate by booking your ride from Denver International Airport about one week ahead of your flight from STL to Denver.

  • The street address for DEN is 8500 Pena Boulevard.

Best time to go to Denver

  • Plan your trip to Denver in peak season if you want a lively atmosphere, but remember that hotel prices may be higher. Alternatively, book your flights from Lambert-St. Louis International Airport to Denver in the off-season when prices are cheaper and it's not as busy.

  • Lock in a Lambert-St. Louis International Airport to Denver plane ticket with a departure in July if you're eager to visit the city during its warmest month. Expect temperatures to range from 14ºC (57ºF) to 32ºC (90ºF).

  • If you like travelling in cooler conditions, search for a cheap ticket from STL to Denver in January when temperatures average between -9ºC (16ºF) and 7ºC (45ºF).

More about Denver

Explore more of United States

  • Denver is always a good idea, but there are so many other parts of United States just waiting to be discovered. About 65 miles south of Denver, a visit to Colorado Springs will keep you on the go. Don't miss top attractions like US Northern Command (USNORTHCOM) / North American Aerospace Defence Command (NORAD) Headquarters, Cheyenne Mountain Air Force Station and National Strength and Conditioning Association (NSCA).

  • Pueblo is another sought-after destination in United States and is around 100 miles south of Denver. No trip is complete without experiencing Pueblo Weisbrod Aircraft Museum, Rosemount Museum and Pueblo Zoo.

Plan the rest of your trip from St Louis to Denver

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