$40 Find Cheap Flights from Denver to St. Charles

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Denver to St. Charles departing on 6/11. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
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Cheap Flight Deals from Denver to St. Charles (DEN-STL)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Denver to St. Charles that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.

Recent round-trip flight deals from Denver to St. Charles

KAYAK's recommended round-trip deals from the most popular airlines that fly from Denver to St. Charles.
Discover the best prices for you by selecting your travel dates on KAYAK.
Frontier Logo
7:00 am - 10:08 amDEN-STL
2h 08mnonstop
Frontier Logo
7:29 pm - 8:56 pmSTL-DEN
2h 27mnonstop
$116Frontier
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Wed, Jun 11 - Wed, Jun 18
Frontier Logo
7:00 am - 10:08 amDEN-STL
2h 08mnonstop
Frontier Logo
7:29 pm - 8:56 pmSTL-DEN
2h 27mnonstop
$131Frontier
Find Deal
Wed, Jun 11 - Fri, Jun 13
 Logo
6:30 pm - 2:54 pmDEN-STL
19h 24m1 stop
 Logo
7:24 pm - 8:51 pmSTL-DEN
2h 27mnonstop
Fri, May 30 - Mon, Jun 2
United Airlines Logo
8:40 pm - 11:59 pmDEN-STL
2h 19mnonstop
United Airlines Logo
4:32 pm - 6:01 pmSTL-DEN
2h 29mnonstop
$210United Airlines
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Wed, Jun 11 - Tue, Jun 17
Delta Logo
12:55 am - 9:35 amDEN-STL
7h 40m1 stop
Delta Logo
7:30 am - 12:04 pmSTL-DEN
5h 34m1 stop
$217Delta
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Fri, May 30 - Wed, Jun 4
Southwest Logo
10:25 am - 1:30 pmDEN-STL
2h 05mnonstop
Southwest Logo
5:55 am - 7:15 amSTL-DEN
2h 20mnonstop
$220Southwest
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Wed, May 21 - Tue, May 27
United Airlines Logo
1:25 pm - 4:31 pmDEN-STL
2h 06mnonstop
United Airlines Logo
4:32 pm - 6:01 pmSTL-DEN
2h 29mnonstop
$223United Airlines
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Tue, May 27 - Tue, Jun 3
Southwest Logo
7:00 am - 12:50 pmDEN-STL
4h 50m1 stop
Southwest Logo
5:20 am - 8:50 amSTL-DEN
4h 30m1 stop
$235Southwest
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Wed, May 21 - Tue, May 27
Delta Logo
12:59 am - 9:00 amDEN-STL
7h 01m1 stop
Delta Logo
3:40 pm - 9:57 pmSTL-DEN
7h 17m1 stop
$243Delta
Find Deal
Mon, May 26 - Tue, Jun 3
 Logo
6:30 pm - 2:54 pmDEN-STL
19h 24m1 stop
 Logo
9:50 am - 4:01 pmSTL-DEN
31h 11m3 stops
Fri, May 30 - Thu, Jun 5
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Good to know

Low seasonJanuary
High seasonMay
Cheapest flight$40
Best time to beat the crowds with an average 16% drop in price.
Most popular time to fly and prices are also 17% lower on average.
Flight from Denver to St. Louis

When to book flights from Denver to St. Charles

Are your dates flexible? Find out the best times to travel from Denver to St. Charles based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price

FAQs for booking flights from Denver to St. Charles

  • Which airports will I be using when flying from Denver to St. Charles?

    When flying out of Denver you’ll be using Denver Intl. St. Charles does not have its own airport so you’ll be flying into nearby Lambert-St Louis airport, which is 7.2 mi away.

  • How long does a flight from Denver to St. Charles take?

    Direct flights cover the 767 miles separating Denver and St. Charles in about 2h 00m.

  • How many flights are there between Denver and St. Charles?

    19 direct flights run between Denver and St. Charles on a daily basis. On average, there are about 138 departures each week.

  • What’s the cheapest day of the week to fly between Denver and St. Charles?

    Consider leaving on a Wednesday and avoid Thursdays if you are looking for the best rates. For your return to Denver, you’ll find the best rates on Saturdays and the most expensive ones on Mondays.

  • How does KAYAK find such low prices on flights from Denver to St. Charles?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Denver to St. Charles.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Denver to St. Charles?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to St. Charles from Denver is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Denver to St. Charles?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to St. Charles with an airline and back to Denver with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Denver to St. Charles?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to St. Charles from Denver up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • Which airlines provide the cheapest flights from Denver to St. Charles?

    In the last 72 hours, the cheapest one-way ticket between Denver and St. Charles found on KAYAK was with Frontier for $40. Frontier offered a round-trip connection from $116 and United Airlines from $210.

Top tips for finding cheap flights from Denver to St. Charles

  • There is no airport in St. Charles. Instead, you’ll be flying into St. Louis Lambert Airport when flying between Denver and St. Charles.
  • The cheapest flight from Denver to St. Charles was found 78 days before departure, on average.
  • Book at least 1 week before departure in order to get a below-average price.
  • High season is considered to be February, March and April. The cheapest month to fly is July.

Top 3 airlines serving Denver to St. Charles

Need help choosing which airline to fly with from Denver to St. Charles? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
SouthwestOverall score based on 4294 reviews
7.1Food
8.2Boarding
8.6Crew
7.6Entertainment
8.0Comfort
Airline reviews

I would have liked to arrive on time - not 5 hours late!

4.0 OkayAnonymous, Apr 2025DEN - SEA
Read more Southwest reviews

I would have liked to arrive on time - not 5 hours late!

1.5 hour delay, poor service, no compassion from the crew. Terrible experience

Our flight was diverted from being a non-stop to getting within 150 miles and requiring another plane. We heard 4 or 5 different versions from SW as to why we had to stop, then wait for a replacement plane. Five hour delay, weather did not come up as a single excuse.... communication was not clear and well explained. No one really took charge!

I really like open seating. I hate that I've heard this is going away. This is one of the unique things that makes Southwest my goto choice.

It was 2 hours 45 minutes late, for no apparently clear reason.

Crew was great flight was great baggage claim was a failure. It took over 1 hour for bags to arrive. Poor communication poor effort when I spoke to the supervisor about the delay

Everything was great except the food. The pretzels are really crappy.

It seems as though the provisions are even less. Although SWA used to be an economy Airline, that isn't really the case anymore. I paid over $700. for a round trip to Denver and I could have flown just about any airline for the price. The drinks are now in a 6-ounce cup and with ice I'm sure a can would fill more than 2 cups. However, I am very proud of SWA for using paper rather than continuing to contribute to the millions of plastic cups being used each day. I've thought of this fr many years and am so glad to see it come to fruition, if not by only SWA so far.

My original flight was extremely delayed but I was able to join the standby list for an earlier flight. I was grateful for this feature but I wish I could’ve gotten my standby confirmation sooner.

Excellent. The lady boarding the flight was awesome. Very efficient, and she got everyone on line.

Electric plugs didn't work. Entertainment system wasn't working

The design of the light switch on the arm rest is ridiculous.

The gate attendant let me walk right by her with a bag too big for the overhead compartment

Overall, it was a good experience. Boarding was good and there was plenty of overhead bin space for everyone’s carryons (even when we boarded toward the end). Only improvement would be to offer trash service more regularly.

David went above and beyond to make our flight the best that it could be

No food service almost missed because of first flight delays

Had a hard time finding my assigned seat. No attendants to assist.

The negative was the wait at the airport coming back. I checked my bags in, an hour before boarding and I get the notification that my flight was delayed. Rather had gotten the notification while I was at the hotel. Then it was delayed 3 x’s. Ugh!

Plane still had screens for watching movies. Good selection too.

There was no air on the plane and it was very hot.

Everything went as planned. Crew was great. Seats were still not that comfortable.

they delayed my flight which ended up, causing my layover flight to leave without me, resulting in me missing a flight and having to stay overnight in Houston international. I got no compensation other than a flight to my original location only a day later. i’ve never experienced such a unprofessional situation

The seats were extremely hard and uncomfortable, even for a budget airline.

Boarding was very well executed. Got my bag right away.

Overall experience good. There was no food and seats were not terribly comfortable.

There was nothing to like, flight delayed had to move to different departure areas, disorganized to say the leasr

There were a lot of issues every step of the process. Check in, security, boarding, and dealing with luggage. Plus the money you think you are saving you end up using in hidden fees.

The flight attendant was arguing with a passenger before takeoff. The passenger was frustrated but the flight attendant should have handled it with grace, but instead she was nasty and rude. The seats were comfortable and the flight was uneventful. I wish we didn’t have to pay for drinks or snacks but that’s what you get with a budget airline.

Booked two aisle seats and were switched to an aisle and middle. Not happy.

I fly Frontier often and generally don't have any issues. For some reason, the Denver to Houston's George Bush Intercontinental (IAH) flight always needs to wait on the tarmac in Houston because a gate is not available after landing. I've been stuck for as little as 15 minutes and as much as a little over an hour. I know only fly the Frontier Denver to IAH route when there is not an available flight to Houston Hobby (HOU).

Everything you need to know for your flight from Denver to St. Charles

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