Cheap flights from Denver to St. Louis 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 Denver to St. Louis departing on 10/22. 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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Frontier Logo
6:00 am - 9:07 amDEN-STL
2h 07mnonstop
Frontier Logo
7:45 pm - 9:13 pmSTL-DEN
2h 28mnonstop
$99Frontier
Find Deal
Fri, Nov 7 - Mon, Nov 10
Frontier Logo
6:00 am - 9:07 amDEN-STL
2h 07mnonstop
Frontier Logo
7:52 pm - 9:20 pmSTL-DEN
2h 28mnonstop
$100Frontier
Find Deal
Mon, Oct 20 - Fri, Oct 24
Frontier Logo
6:00 am - 9:07 amDEN-STL
2h 07mnonstop
Frontier Logo
7:52 pm - 9:20 pmSTL-DEN
2h 28mnonstop
$101Frontier
Find Deal
Thu, Oct 23 - Fri, Oct 24
Frontier Logo
6:00 am - 9:07 amDEN-STL
2h 07mnonstop
Frontier Logo
7:45 pm - 9:13 pmSTL-DEN
2h 28mnonstop
$103Frontier
Find Deal
Mon, Nov 3 - Mon, Nov 10
Frontier Logo
6:00 am - 9:07 amDEN-STL
2h 07mnonstop
Frontier Logo
7:45 pm - 9:13 pmSTL-DEN
2h 28mnonstop
$104Frontier
Find Deal
Thu, Nov 6 - Mon, Nov 10
Frontier Logo
6:00 am - 9:07 amDEN-STL
2h 07mnonstop
Frontier Logo
7:52 pm - 9:20 pmSTL-DEN
2h 28mnonstop
$106Frontier
Find Deal
Fri, Oct 24 - Mon, Oct 27
Frontier Logo
6:00 am - 9:07 amDEN-STL
2h 07mnonstop
Frontier Logo
7:45 pm - 9:13 pmSTL-DEN
2h 28mnonstop
$107Frontier
Find Deal
Wed, Nov 12 - Fri, Nov 14
Frontier Logo
6:00 am - 9:07 amDEN-STL
2h 07mnonstop
Frontier Logo
7:45 pm - 9:13 pmSTL-DEN
2h 28mnonstop
$109Frontier
Find Deal
Fri, Nov 14 - Sun, Nov 16
Frontier Logo
6:00 am - 9:07 amDEN-STL
2h 07mnonstop
Frontier Logo
7:52 pm - 9:20 pmSTL-DEN
2h 28mnonstop
$111Frontier
Find Deal
Sun, Oct 19 - Thu, Oct 23
Frontier Logo
6:00 am - 9:07 amDEN-STL
2h 07mnonstop
Frontier Logo
7:45 pm - 9:13 pmSTL-DEN
2h 28mnonstop
$113Frontier
Find Deal
Thu, Nov 13 - Sun, Nov 16

Frontier flights from Denver to St. Louis

Our best Frontier deals on Denver to St. Louis flight tickets
Frontier
Nov 7
DEN6:00 amDenver Intl
2h 07m
STL9:07 amLambert-St Louis
Nov 10
STL7:45 pmLambert-St Louis
2h 28m
DEN9:13 pmDenver Intl
Frontier
Oct 20
DEN6:00 amDenver Intl
2h 07m
STL9:07 amLambert-St Louis
Oct 24
STL7:52 pmLambert-St Louis
2h 28m
DEN9:20 pmDenver Intl
Frontier
Oct 23
DEN6:00 amDenver Intl
2h 07m
STL9:07 amLambert-St Louis
Oct 24
STL7:52 pmLambert-St Louis
2h 28m
DEN9:20 pmDenver Intl

Delta flights from Denver to St. Louis

Our best Delta deals on Denver to St. Louis flight tickets
Delta
Oct 13
DEN12:50 amDenver Intl
6h 15m
1 stop
STL8:05 amLambert-St Louis
Oct 22
STL1:40 pmLambert-St Louis
7h 35m
1 stop
DEN8:15 pmDenver Intl
Delta
Oct 11
DEN5:30 amDenver Intl
7h 09m
1 stop
STL1:39 pmLambert-St Louis
Oct 14
STL1:30 pmLambert-St Louis
7h 45m
1 stop
DEN8:15 pmDenver Intl
Delta
Oct 13
DEN12:50 amDenver Intl
6h 15m
1 stop
STL8:05 amLambert-St Louis
Oct 16
STL6:52 pmLambert-St Louis
6h 07m
1 stop
DEN11:59 pmDenver Intl

momondo Fare Finder

 
Customize your flight search to find flights from Denver to St. Louis that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 832,500 searches. Data last updated October 6, 2025.
Use the filters below to find and compare flights from Denver to St. Louis that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Fri 11/7

6:00 am-9:07 am

Nonstop2h 07m

Lambert-St Louis

Mon 11/10

7:45 pm-9:13 pm

Nonstop2h 28m

$99

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Mon 10/20

6:00 am-9:07 am

Nonstop2h 07m

Lambert-St Louis

Fri 10/24

7:52 pm-9:20 pm

Nonstop2h 28m

$100

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Thu 10/23

6:00 am-9:07 am

Nonstop2h 07m

Lambert-St Louis

Fri 10/24

7:52 pm-9:20 pm

Nonstop2h 28m

$101

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Mon 11/3

6:00 am-9:07 am

Nonstop2h 07m

Lambert-St Louis

Mon 11/10

7:45 pm-9:13 pm

Nonstop2h 28m

$103

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Thu 11/6

6:00 am-9:07 am

Nonstop2h 07m

Lambert-St Louis

Mon 11/10

7:45 pm-9:13 pm

Nonstop2h 28m

$104

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Fri 10/24

6:00 am-9:07 am

Nonstop2h 07m

Lambert-St Louis

Mon 10/27

7:52 pm-9:20 pm

Nonstop2h 28m

$106

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Wed 11/12

6:00 am-9:07 am

Nonstop2h 07m

Lambert-St Louis

Fri 11/14

7:45 pm-9:13 pm

Nonstop2h 28m

$107

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Fri 11/14

6:00 am-9:07 am

Nonstop2h 07m

Lambert-St Louis

Sun 11/16

7:45 pm-9:13 pm

Nonstop2h 28m

$109

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Sun 10/19

6:00 am-9:07 am

Nonstop2h 07m

Lambert-St Louis

Thu 10/23

7:52 pm-9:20 pm

Nonstop2h 28m

$111

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Thu 11/13

6:00 am-9:07 am

Nonstop2h 07m

Lambert-St Louis

Sun 11/16

7:45 pm-9:13 pm

Nonstop2h 28m

$113

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to St. Louis from

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

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 St. Louis?

In general, January is the cheapest month to fly from Denver to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $168. The month of August is another great option to travel to St. Louis, with average flight prices from Denver averaging around $194.

What is the cheapest day to depart on your flight to St. Louis?

The cheapest day to depart on your flight to St. Louis is on a Friday when prices can be found for as low as $223. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Sunday because tickets tend to average around $318. These prices are subject to change though, so be sure to set up a Price Alert for flights to St. Louis.

What is the cheapest time of day to depart on your flight to St. Louis?

Flying to St. Louis from Denver in the evening is the least expensive time of day to depart. momondo users have found prices as low as $230 when looking at flights departing in the evening. In the afternoon is when there is more demand to fly to St. Louis, so prices are often more expensive at around $309 per ticket.

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

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

How far in advance should I book a flight to St. Louis?

You are more likely to see cheaper flights to St. Louis from Denver when booking weeks ahead of your departure date. In general, you can expect to find flights to St. Louis for around $228 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to St. Louis from Denver for as low as $158 on momondo.

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

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

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

As of October 2025, prices for Denver to St. Louis flights are approximately 25% cheaper when compared to flights at the same time last year.

When to book flights from Denver to St. Louis

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

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

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

Best Price Found

$81

Fastest flight time

2h 00m

Direct flights

Every day

Airports in St. Louis

1 airport
The best one-way flight to St. Louis from Denver in the past 72 hours is $81. The best round-trip flight deal from Denver to St. Louis found on momondo in the last 72 hours is $170.
The fastest flight from Denver to St. Louis takes 2h 00m
Direct flights go from Denver to St. Louis every day.
There is 1 airport near St. Louis: Lambert-St Louis (STL)
  • How far is Denver Intl to Lambert-St Louis by plane?

    The distance between Denver Intl and Lambert-St Louis is about 794.2 mi. A reasonable flight in good conditions will take 2h 05m.

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

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

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

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

    The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Denver Intl Airport to Lambert-St Louis Airport.

  • What documentation or ID do you need to fly to Lambert-St Louis Airport?

    The necessary travel and health documents for your Lambert-St Louis 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 Denver to St. Louis?

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

Best airlines flying from Denver to St. Louis

Compare and see reviews for airlines that fly from Denver to St. Louis with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $56Free CancellationRating
5.8
3,146 reviews
Search Frontier flights
United AirlinesPriceFrom $154Free CancellationRating
7.4
8,957 reviews
Search United Airlines flights
SouthwestPriceFrom $177Free CancellationRating
8.0
4,232 reviews
Search Southwest flights
  • Southwest Flights From Denver to St. Louis

    Southwest is one of the most popular airlines flying from Denver to St. Louis, operating 35 flights/week on average for this route. A good Southwest flight deal for Denver to St. Louis starts from $177 round-trip, up to an average price of $300. Our users have rated Southwest at 8.0/10.

  • United Airlines Flights From Denver to St. Louis

    Another popular option for Denver to St. Louis flights is United Airlines (7.4/10, 8,957 ratings). United Airlines flies from Denver to St. Louis around 31 times per week, with deals starting from $154 round-trip and rising to an average price of around $326.

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
St. Charles
Chesterfield
Hermann
Fairview Heights
Florissant
Maryland Heights
O'Fallon
Collinsville
Fenton
Wentzville
St. Peters
Alton
Farmington
Festus
Glencoe
Clayton
Edwardsville
Eureka
Litchfield
Shrewsbury

Why use momondo?

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

momondo collates all your flight options in one place and lets you filter them to find the perfect flight from Denver to St. Louis. momondo saves you time and could save you money on your trip.

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

All flight searches from Denver to St. Louis on momondo can be filtered to show those which offer flexible booking policies.

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

Once you have performed a search for Denver to St. Louis flights, momondo helps you find the right one by offering useful filters to narrow down your flight selection. Flights can be filtered by multiple factors such as airline, airport and price; but also by other criteria like aircraft type and payment method.

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

If you are simply researching potential flights to St. Louis, momondo offers a useful price alert feature which will track prices for flights to St. Louis from Denver and alert you when they change.

An easier way to manage your St. Louis trip

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1 adult
Wed 11/5
Wed 11/12

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