Cheap flights from St. Louis to Denver from $38

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from St. Louis to Denver departing on 9/6. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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0 bags

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Cheap round-trip flights

Frontier Logo
7:52 pm - 9:20 pmSTL-DEN
2h 28mnonstop
Frontier Logo
6:00 am - 9:07 amDEN-STL
2h 07mnonstop
$91Frontier
Find Deal
Sat, Oct 25 - Tue, Oct 28
Frontier Logo
7:52 pm - 9:20 pmSTL-DEN
2h 28mnonstop
Frontier Logo
6:00 am - 9:07 amDEN-STL
2h 07mnonstop
$97Frontier
Find Deal
Sat, Oct 25 - Tue, Oct 28
Frontier Logo
7:52 pm - 9:20 pmSTL-DEN
2h 28mnonstop
Frontier Logo
6:00 am - 9:07 amDEN-STL
2h 07mnonstop
$101Frontier
Find Deal
Thu, Oct 9 - Tue, Oct 14
Frontier Logo
7:55 pm - 9:20 pmSTL-DEN
2h 25mnonstop
Frontier Logo
6:00 am - 9:06 amDEN-STL
2h 06mnonstop
$106Frontier
Find Deal
Tue, Sep 23 - Sat, Sep 27
Frontier Logo
7:55 pm - 9:20 pmSTL-DEN
2h 25mnonstop
Frontier Logo
6:00 am - 9:06 amDEN-STL
2h 06mnonstop
$113Frontier
Find Deal
Mon, Sep 15 - Sat, Sep 20
Southwest Logo
1:45 pm - 6:40 pmSTL-DEN
5h 55m1 stop
Southwest Logo
5:15 pm - 8:15 pmDEN-STL
2h 00mnonstop
$142Southwest
Find Deal
Sat, Oct 25 - Tue, Oct 28
Southwest Logo
8:45 pm - 10:05 pmSTL-DEN
2h 20mnonstop
Southwest Logo
9:40 am - 5:45 pmDEN-STL
7h 05m2 stops
$148Southwest
Find Deal
Tue, Sep 23 - Sat, Sep 27
Southwest Logo
6:40 pm - 8:00 pmSTL-DEN
2h 20mnonstop
Southwest Logo
5:30 am - 8:30 amDEN-STL
2h 00mnonstop
$150Southwest
Find Deal
Thu, Sep 18 - Mon, Sep 22
American Airlines Logo
2:11 pm - 10:02 pmSTL-DEN
8h 51m1 stop
American Airlines Logo
8:10 am - 6:41 pmDEN-STL
9h 31m1 stop
$159American Airlines
Find Deal
Thu, Sep 4 - Sat, Oct 4
American Airlines Logo
9:23 am - 1:55 pmSTL-DEN
5h 32m1 stop
American Airlines Logo
7:02 am - 4:56 pmDEN-STL
8h 54m1 stop
$166American Airlines
Find Deal
Fri, Aug 15 - Mon, Aug 25

Frontier flights from St. Louis to Denver

Our best Frontier deals on St. Louis to Denver flight tickets
Frontier
Oct 25
STL7:52 pmLambert-St Louis
2h 28m
DEN9:20 pmDenver Intl
Oct 28
DEN6:00 amDenver Intl
2h 07m
STL9:07 amLambert-St Louis
Frontier
Oct 25
STL7:52 pmLambert-St Louis
2h 28m
DEN9:20 pmDenver Intl
Oct 28
DEN6:00 amDenver Intl
2h 07m
STL9:07 amLambert-St Louis
Frontier
Oct 9
STL7:52 pmLambert-St Louis
2h 28m
DEN9:20 pmDenver Intl
Oct 14
DEN6:00 amDenver Intl
2h 07m
STL9:07 amLambert-St Louis

American Airlines flights from St. Louis to Denver

Our best American Airlines deals on St. Louis to Denver flight tickets
American Airlines
Sep 4
STL2:11 pmLambert-St Louis
8h 51m
1 stop
DEN10:02 pmDenver Intl
Oct 4
DEN8:10 amDenver Intl
9h 31m
1 stop
STL6:41 pmLambert-St Louis
American Airlines
Aug 15
STL9:23 amLambert-St Louis
5h 32m
1 stop
DEN1:55 pmDenver Intl
Aug 25
DEN7:02 amDenver Intl
8h 54m
1 stop
STL4:56 pmLambert-St Louis

See travel insights to Denver from

How to get the cheapest flight ticket from St. Louis to Denver

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest month to fly to Denver?

The cheapest month to fly to Denver from St. Louis is in September. Flight prices, which tend to average around $157, are often lower during this time because this is during the off-season. If you don’t want to visit Denver in September, then you should wait until August to fly from St. Louis, when ticket prices are also cheap, with an average price of $158.

What is the cheapest day to depart on your flight to Denver?

The cheapest day to depart on your flight to Denver is on a Wednesday when prices can be found for as low as $294. This is often the case because there is less demand to fly during this day of the week. The most expensive day to fly to Denver is Sunday, with ticket prices averaging around $418.

What is the cheapest time of day to depart on your flight to Denver?

The cheapest time of day to fly to Denver is in the evening when flights can be purchased for as low as $166. Flights in the morning are often more expensive with an average ticket price of $470.

What is the cheapest Lambert-St Louis to Denver Intl flight route?

Fly from Lambert-St Louis to Denver Intl for the best Lambert-St Louis - Denver Intl flight prices

How far in advance should I book a flight to Denver?

You are more likely to see cheaper flights to Denver from St. Louis when booking weeks ahead of your departure date. In general, you can expect to find flights to Denver for around $211 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Denver from St. Louis for as low as $151 on momondo.

What cabin class options are available on Lambert-St Louis to Denver Intl flights?

There are 4 cabin classes available to choose from on Lambert-St Louis to Denver Intl flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

How have St. Louis to Denver flight prices changed over time?

As of July 2025, prices for St. Louis to Denver flights are approximately 38% cheaper when compared to flights at the same time last year.

When to book flights from St. Louis to Denver

Are you open to changing your travel dates? Check out the ideal times to fly from St. Louis to Denver according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap St. Louis to Denver (STL to DEN) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from St. Louis to Denver

Best Price Found

$38

Fastest flight time

2h 15m

Direct flights

Every day

Airports in Denver

1 airport
The best one-way flight to Denver from St. Louis in the past 72 hours is $38. The best round-trip flight deal from St. Louis to Denver found on momondo in the last 72 hours is $91.
The fastest flight from St. Louis to Denver takes 2h 15m
Direct flights go from St. Louis to Denver every day.
There is 1 airport near Denver: Denver Intl (DEN)

  • How far is Lambert-St Louis to Denver Intl by plane?

    The straight-line distance from Lambert-St Louis to Denver Intl is 794.2 mi. Typically, this will take 2h 15m by plane in normal conditions.

  • When did momondo last update prices for flights from Lambert-St Louis Airport to Denver Intl Airport?

    Prices for flights from Lambert-St Louis Airport to Denver Intl Airport were last updated today.

  • How many operators does momondo search for flights from Lambert-St Louis Airport to Denver Intl Airport?

  • How old do you have to be to fly from Lambert-St Louis Airport to Denver Intl Airport?

    The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Lambert-St Louis Airport to Denver Intl Airport.

  • What documentation or ID do you need to fly to Denver Intl Airport?

    The necessary travel and health documents for your Denver Intl Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

  • What is the most popular plane model from St. Louis to Denver?

  • What is the most popular airline from St. Louis to Denver?


Best airlines flying from St. Louis to Denver

Compare and see reviews for airlines that fly from St. Louis to Denver with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $45Free CancellationRating
5.9
3,271 reviews
Search Frontier flights
DeltaPriceFrom $128Free CancellationRating
8.0
7,952 reviews
Search Delta flights
United AirlinesPriceFrom $153Free CancellationRating
7.4
8,846 reviews
Search United Airlines flights
SouthwestPriceFrom $178Free CancellationRating
8.0
4,250 reviews
Search Southwest flights
American AirlinesPriceFrom $201Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights
  • Southwest Flights From St. Louis to Denver

    The lowest priced Southwest flight from St. Louis to Denver from the last 72 hours was $178. Generally, Southwest has 44 flights on this route every week with an average price of $297. Southwest is rated 8.0/10 by our users.

  • United Airlines Flights From St. Louis to Denver

    Across 8,846 United Airlines reviews on momondo, the average score is 7.4/10. United Airlines flies from St. Louis to Denver about 27 times each week, with ticket deals ranging from $153 to $310. Price data is based on momondo searches in the last 72 hours.


Traveling to a place near Denver?

Book flights to Denver if you plan to visit one of these locations
Estes Park
Breckenridge
Black Hawk
Aurora
Fort Collins
Keystone
Cripple Creek
Longmont
Boulder
Lakewood
Manitou Springs
Greeley
Westminster
Thornton
Winter Park
Silverthorne
Copper Mountain
Grand Lake
Golden
Frisco

Why use momondo?

Why should I use momondo to find a flight deal from St. Louis to Denver?

Finding the right flight to Denver from St. Louis is quick and easy when you have a range of options in front of you, from reputable agents and recognisable airlines. Options that can then be filtered down to find the best fit. That is what momondo does. We make finding flights to Denver quick and easy, saving you time and money.

Can I find flights from St. Louis to Denver with flexible booking policies on momondo?

momondo does allow users to show only those flights to Denver from St. Louis which offer a flexible booking policy as well as other useful filters and features.

How can momondo help me find flights from St. Louis to Denver?

momondo provides multiple filters to help you find the best flight to Denver from St. Louis. Filter by price, airline, airports, cabin, aircraft, payment method, number of stops and more.

I’m not ready to book a flight from St. Louis to Denver right now. Can momondo alert me if prices change?

Of course. momondo tracks the price of St. Louis to Denver flights. All you need is a valid email address and we will do the rest; it is that quick and easy.


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1 adult
Tue 7/15
Tue 7/22

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