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STL - DEN

Find cheap flights from St. Louis to Denver from $35

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from St. Louis to Denver departing on 5/14. 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.
1 adult
0 bags
Fri 5/24
Fri 5/31

Search hundreds of travel sites at once for deals on flights to Denver

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to Denver, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to Denver, as well as popular online travel agencies
In the last 7 days travelers have searched 44,632,927 times on KAYAK, and here is why:

Save 22% or moreCompare multiple travel sites with one search.

Track pricesNot ready to book? Create a price alert for when prices drop.

Filter your dealsChoose cabin class, free Wi-Fi and more.

Bundle and saveSave money when you bundle your flight + hotel.

Cheap flight deals from St. Louis to Denver (STL-DEN)

Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from St. Louis to Denver 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.
Discover the best prices and deals for you by selecting your travel dates.
Choose your dates
8:02 pm - 9:33 pmSTL-DEN
2h 31mnonstop
6:20 am - 9:30 amDEN-STL
2h 10mnonstop
$42Frontier
Find Deal
Wed, Jun 12 - Wed, Jun 19
10:44 pm - 12:20 amSTL-DEN
2h 36mnonstop
6:20 am - 9:30 amDEN-STL
2h 10mnonstop
$46Frontier
Find Deal
Tue, Jun 4 - Wed, Jun 12
8:04 pm - 9:35 pmSTL-DEN
2h 31mnonstop
10:00 am - 1:09 pmDEN-STL
2h 09mnonstop
$57Frontier
Find Deal
Sat, May 18 - Tue, May 21
8:45 pm - 10:16 pmSTL-DEN
2h 31mnonstop
6:26 am - 9:36 amDEN-STL
2h 10mnonstop
$60Frontier
Find Deal
Fri, May 17 - Wed, May 22
8:04 pm - 9:35 pmSTL-DEN
2h 31mnonstop
12:45 pm - 3:50 pmDEN-STL
2h 05mnonstop
$64Frontier
Find Deal
Sat, May 11 - Tue, May 14
8:04 pm - 9:35 pmSTL-DEN
2h 31mnonstop
6:41 am - 9:47 amDEN-STL
2h 06mnonstop
$68Frontier
Find Deal
Sat, May 11 - Mon, May 13
5:30 pm - 11:14 pmSTL-DEN
6h 44m1 stop
6:10 pm - 12:46 amDEN-STL
5h 36m1 stop
$176Delta
Find Deal
Wed, May 29 - Wed, Jun 5
3:05 pm - 7:49 pmSTL-DEN
5h 44m1 stop
12:55 am - 9:10 amDEN-STL
7h 15m1 stop
$187Delta
Find Deal
Tue, Jun 4 - Mon, Jun 10
7:30 am - 8:52 amSTL-DEN
26h 22m1 stop
7:55 am - 4:10 pmDEN-STL
7h 15m1 stop
$195Sun Country Air
Find Deal
Thu, Oct 3 - Sat, Oct 5
7:23 pm - 7:58 amSTL-DEN
13h 35m1 stop
6:05 pm - 5:25 pmDEN-STL
22h 20m1 stop
Sun, May 19 - Sat, May 25

Flights from St. Louis to Denver - Travel Insights & Trends

Get data-powered insights and trends into flights from St. Louis to Denver to help you find the cheapest flights, the best time to fly and much more.

What’s the cheapest day of the week to fly from St. Louis to Denver?

The average price of all flights from St. Louis to Denver clicked on KAYAK for each day over the last 12 months.
When flying from St. Louis to Denver, you should consider leaving on a Tuesday and avoid Mondays if you are looking for the best rates. For your return to St. Louis, you’ll find the best rates on Wednesdays and the most expensive ones on Mondays.

What is the cheapest month to fly from St. Louis to Denver?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for flights from St. Louis to Denver, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.
The cheapest month for flights from St. Louis to Denver is October, where tickets cost $118 on average. On the other hand, the most expensive months are December and July, where the average cost of tickets is $220 and $188 respectively.

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

To calculate daily average prices, KAYAK takes all prices for each day before departure over the last year for flights from St. Louis to Denver, removes the top 0.1% to account for outliers, and then takes the average of all the values for each month.
To get a below average price on the flight from St. Louis to Denver, you should book around 1 week before departure. For the absolute cheapest price, our data suggests you should book 55 days before departure.

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

The cheapest price for the route for each airline clicked by KAYAK users in the last 72 hours.
In the last 72 hours, the cheapest one-way ticket from St. Louis to Denver found on KAYAK was with Frontier for $35. Frontier proposed a round-trip connection from $42 and Delta from $176.

Which airlines fly most frequently between St. Louis and Denver?

Southwest connects St. Louis to Denver up to 7 flights per day, followed by United Airlines (3 flights per day), and Frontier (one flight per day).

Which airlines fly non-stop between St. Louis and Denver?

Airline and price data is aggregated from results in KAYAK’s search results from the last 2 weeks for flights from St. Louis to Denver.
There are 3 airlines that fly nonstop from St. Louis to Denver. They are: Frontier, Southwest and United Airlines. The cheapest price of all airlines flying this route was found with Frontier at $39 for a one-way flight. On average, the best prices for this route can be found at Frontier.

How many flights are there between St. Louis and Denver per day?

Each day, there are between 11 and 14 nonstop flights that take off from St. Louis and land in Denver, with an average flight time of 2h 23m. The most common departure time is 4:00 pm and most flights take off in the afternoon. Each week, there are 90 flights. The most frequent day of departure is Friday, when 16% of all weekly flights depart. The fewest flights depart on a Wednesday.

Which cabin class options are there for flights between St. Louis and Denver?

The average price of flights for each cabin class for the route found by users searching on KAYAK over the last 2 weeks.
There are 4 cabin class options for the route. These are First, Business, Economy and Prem Economy. Perform a search on KAYAK to find the latest prices and availability for all cabin fares, which differ across airlines.

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

The duration of a nonstop flight to Denver from St. Louis is typically 2h 22m. The journey crosses a distance of 767 miles.

What’s the earliest departure time from St. Louis to Denver?

Early birds can take the earliest flight from St. Louis at 5:35 am and will be landing in Denver at 6:55 am.

What’s the latest departure time from St. Louis to Denver?

If you prefer to fly at night, the latest flight from St. Louis to Denver jets off at 11:22 pm and lands at 12:49 am.

Good to know

Low season

April

High season

July

Cheapest flight

$35
Best time to beat the crowds with an average 2% drop in price.
Most popular time to fly with an average 21% increase in price.
Flight from St. Louis to Denver

When to book flights from St. Louis to Denver

Are your dates flexible? Find out the best times to travel from St. Louis to Denver based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking flights from St. Louis to Denver

  • How can I fly from STL to DEN?

    Frontier and United operate several nonstop flights from STL to DEN that depart throughout the day. American and United operate several flights per day that have one stop. The layover for these flights is often in cities such as Chicago (ORD), Charlotte (CLT), and Dallas (DFW).

  • Does STL have a USO lounge?

    STL provides a USO lounge for active military service members and their families. The James S. McDonnell USO, located in Terminal 1 on the lower level opposite M6 baggage claim, is open 24h a day, 7 days a week, 365 days a year. All services and amenities at the USO are without charge. Some of these offerings include beverages, snacks, Wi-Fi, a DSN phone, laptops, and computers. You can also relax by watching cable TV, watching a DVD or a Blu-ray disc, or playing Xbox 360. The USO also has a seating area, a quiet area where you can sleep, a nursery, and toiletries.

  • Does STL have designated lactation areas for nursing mothers who might prefer some privacy?

    STL provides dedicated private spaces to mothers who want to nurse or breast pump in clean privacy. These lactation suites are located past security at Gates A10, C9, and E33. Each calm, clean room has power outlets for a breast pump, a sink, and a full back comfortable chair with a movable arm table. There is also an Ottoman and a bench so that additional people, such as baby’s siblings, can join mama in the space, with enough room for luggage.

  • How do I get into downtown Denver from the DEN airport?

    You can take the A Line of the RTD bus that runs to the center of Denver. Also, you can take a train that departs from DEN 4 to 6 times an hour. Public transportation from DEN is very convenient to get you into downtown Denver.

  • What is the cheapest flight from St. Louis to Denver?

    In the last 3 days, the lowest price for a flight from St. Louis to Denver was $35 for a one-way ticket and $42 for a round-trip.

  • Do I need a passport to fly between St. Louis and Denver?

    A passport is not required to fly from St. Louis to Denver.

  • Which airlines offer Wi-Fi service onboard planes from St. Louis to Denver?

    American Airlines, Alaska Airlines, Delta, and PSA Airlines offer inflight Wi-Fi service on the St. Louis to Denver flight route.

  • Which aircraft models fly most regularly from St. Louis to Denver?

    The Airbus A319 is the aircraft model that flies most regularly on the St. Louis to Denver flight route.

  • Which airline alliances offer flights from St. Louis to Denver?

    Star Alliance is the only airline alliance operating flights between St. Louis and Denver.

  • On which days can I fly direct from St. Louis to Denver?

    There are nonstop flights from St. Louis to Denver on a daily basis.

  • Which is the best airline for flights from St. Louis to Denver, Delta or United Airlines?

    The two airlines most popular with KAYAK users for flights from St. Louis to Denver are Delta and United Airlines. With an average price for the route of $340 and an overall rating of 8.0, Delta is the most popular choice. United Airlines is also a great choice for the route, with an average price of $299 and an overall rating of 7.4.

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

    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 St. Louis to Denver.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Denver from St. Louis 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 St. Louis to Denver?

    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 Denver with an airline and back to St. Louis with another airline. Booking your flights between St. Louis and DEN can sometimes prove cheaper using this method.

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

    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 Denver from St. Louis up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

See more FAQs

Top tips for finding a cheap flight from STL to Denver

  • Looking for a cheap flight? 25% of our users found flights on this route for $119 or less one-way and $148 or less round-trip.
  • When you arrive at the Denver International Airport (DEN), you can ease the stiffness out of your muscles by getting a massage at the spa, The Massage, at the B concourse on the mezzanine level. Or you could try the Colorado Oasis or Xpres spas at DEN.
  • If when you arrive at DEN you need to pick up some necessities you couldn’t pack due to airline restrictions, stop at the Peak News and Gifts to get the toiletries and essentials you need before heading into Denver.
  • As part of the Lambert Art and Culture Program at the Lambert St. Louis International Airport (STL), the airport has installed a piano permanently in Terminal 1, so travelers are treated to live music as they make their way to their plane.
  • DEN is happy to provide service animals and pets with relief areas in all three terminals, in the middle of all the gates. For A, B, and C terminals, the pet relief areas are near the US mail drop areas. If you are in Jeppesen terminal, the pet relief area is on the northwest side of the second level.
  • If you want to park your car at STL before you head off to Denver, long-term parking lots are available in lots B and D for an affordable price, and payment is usually due at the time you exit the lot. Free shuttles that run every 10min can take you to your terminal.
See more tips

Prefer to fly non-stop from St. Louis to Denver?

Find which airlines fly direct from Lambert-St Louis to Denver Intl, which days they fly and book direct flights.

Nonstop departures

Lambert-St Louis to Denver Intl

Monday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Tuesday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Wednesday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Thursday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Friday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Saturday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Sunday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

See more direct flights

Nonstop returns

Denver Intl to Lambert-St Louis

Monday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Tuesday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Wednesday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Thursday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Friday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Saturday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

Sunday

Air Canada, Frontier, Southwest, +1 more

Air Canada, Frontier, +2 more

See more direct flights
See more direct flights

Top 4 airlines serving from St. Louis to Denver

 
See real verified KAYAK customer reviews for airlines flying from St. Louis to Denver. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from St. Louis to Denver? 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
DeltaOverall score based on 11004 reviews
8.0entertainment
7.9comfort
7.5food
8.2boarding
8.6crew
Airline reviews

On my way home I had a layover. The flight from ATL to CLT was amended 5x while I was waiting. I could have driven home sooner. Overall from Dallas, Tx to Charlotte, NC I started my trip at 4:30pm, I didn’t get home until past midnight. I know things happen, but 5x to make me run back and forth in an airport from different terminals is excessive. I also upgraded to comfort + , I didn’t feel it was worth it. There was no benefit

2.0 MediocreMarisol, Apr 2024DFW - ATL
Read more about Delta reviews

On my way home I had a layover. The flight from ATL to CLT was amended 5x while I was waiting. I could have driven home sooner. Overall from Dallas, Tx to Charlotte, NC I started my trip at 4:30pm, I didn’t get home until past midnight. I know things happen, but 5x to make me run back and forth in an airport from different terminals is excessive. I also upgraded to comfort + , I didn’t feel it was worth it. There was no benefit

On my way home I had a layover. The flight from ATL to CLT was amended 5x while I was waiting. I could have driven home sooner. Overall from Dallas, Tx to Charlotte, NC I started my trip at 4:30pm, I didn’t get home until past midnight. I know things happen, but 5x to make me run back and forth in an airport from different terminals is excessive.

They did a fine job. Can't wait to use Delta in the future.

There was a loud squeaky sound the whole time we were flying.

Had a broken tray in business class. Crew just shrugged it off.

Seat back monitors and outlets were dead and not working.

Everything was great except for the seat. The backrest would not stay in the upright position.

I usually have a positive experience with Delta. Complimentary upgrades are always nice!

Flight delayed about 2 hrs so it made it a VERY late night

It was a crowded flight. They did the best they could.

Positive: Entertainment via phone on the short was great and my first time. Good food and wine and head phones for free. Negative: Seat hardly reclined on the long flight. Breakfast was an egg with a bun. No egg choices and rather have something sweet like bun/jam and Youghurt.

They did get us booked on a later flight, but it made us miss our connecting flight. So, we had to stay and another state overnight with no luggage or clothes. Because they kept our luggage at airport for next flight on the next day.

Flight was on time. Staff were friendly. I paid for Economy Plus but was required to check my standard carry-on luggage due to lack of space on the aircraft. This cost me 30 minutes, unexpectedly, in waiting at the baggage claim. This experience did not meet my expectations.

Crew is way too many times on the intercom re explaining the same thing

Amazing comfortable chairs great snacks super friendly staff pilots did excellent job. Smooth sailing all the way. Definitely be flying United more.

We waited too long to get water while the plane was on the Tarmac awaiting de-icing.

The plane was delayed coming in and on the tarmac. I was coming from another flight so it made for a very long day. The stewardess kept trying to slam the overhead bins closed and I was worried that she had damaged my new luggage. They ran out of snacks and lccdsddd me a hummus box which was nice. It took them a very long time to pick up the garbage so I could not go to the washroom and had little time. To prepare for disbarment. The TV system was hard to control from the armrest and picture wasn’t clear. The crew did apologize several times for the lateness. It took the Denver airport an unusually long time to de-ice the plane.

By in large it was a good experience. The flight crew was great and that's the most important to me. Boarding was fine.

It was fine. Everything ran on time, crew was great.

Staff friendly and app worked really well. Modest delays were frustrating

This flight is frequently delayed. The connections seemingly are more frequently delayed. I’ve missed connections as a result twice on the same route to charlotte then Charleston. Final destination arrival has been the next day, twice in a row. No pilots, no crew. Too many excuses. Unfortunately, my days with American are over.

Entertainment was okay not because anything was wrong but it is a short flight so having no wifi is annoying but understandable. Crew was outstanding as usual

Those seats were way too narrow. I had the middle seat, one person was a very skinny person and we still couldn’t avoid touching each other anytime one of us moved. The other person was larger and we were basically sitting in each others lap the entire flight. There was zero entertainment. The flight was long enough to justify tvs, but no. Gotta sit there in your infant seat and twiddle your thumbs.

The Flight attendant had an attitude and didn't allow anyone any time to prepare for landing despite being absent throughout the entire trip

Flight boarded without pilots. Sat on plane for 3 hrs. after over an hour late boarding. Plane never took off. Had to deplane near midnight. Line for rebooking was 3 hours + long. I had to leave.

The flight was great but board was a nightmare. The gate was changed 4 times during the layover period

The experience was great and much better than the flight going out. of course I was in first class but the service was excellent

Cold air blew constantly on my legs almost making me numb.

Missed the flight because of them and up geting a rental car

Delayd flight out of atl as always miss my conection in dfw no flight untill next day

There were 3 leg for the trip and each leg was delayed by 90 minutes or more. The boarding process takes forever with people waiting on the jetway even though most folks do not have carry-on. The whole process is poorly managed.

Not have to pay for every single item to take a flight. Seating and delays sucked.

Terrible. Seats are bad and the baggage policy is inconsistent

Everything was good, and most importantly on time. They have been extremely tardy in some of my flights

They lost my baggage on my connection flight, it’s been 24 hours since I put my claim in and still no update on my bags.

It’s a cheap airline. I wish they had better seats.

The only issues had were outside of Frontier’s control or weren’t expected. It was a two hour flight they completed fast. We landed almost an hour ahead of schedule. The issues with no entertainment or food weren’t issues since there was no expectations. The issue of the loud or crying babies was outside of frontiers control.

Seats are cramped and very uncomfortable. You have to pay for everything and it is too expensive.

Smooth process and flight. My favorite kind. Uneventful and on-time!

Xmas Day- Flights were on time for departure and arrival, baggage check in and boarding process were hassle free, baggage also arrived without any delay. Satisfied customer on this journey.

Book cheap flights from St. Louis to Denver

Recent one-way flight deals

 
Only flying one-way? Below are some of the best one-way flight deals from St. Louis to Denver found on KAYAK in the last 72 hours.
5/14Tue
nonstopFrontier
2h 30mSTL-DEN
$35
5/17Fri
nonstopFrontier
2h 31mSTL-DEN
$39
6/19Wed
nonstopFrontier
2h 31mSTL-DEN
$45
5/26Sun
1 stopSun Country Air
15h 40mSTL-DEN
$91
5/24Fri
1 stopSun Country Air
24h 05mSTL-DEN
$98
7/24Wed
1 stopDelta
5h 24mSTL-DEN
$99
5/30Thu
1 stopAmerican Airlines
7h 46mSTL-DEN
$103
7/22Mon
1 stopDelta
6h 02mSTL-DEN
$119
5/14Tue
2 stopsUnited Airlines
22h 17mSTL-DEN
$248
5/25Sat
2 stopsUnited Airlines
14h 23mSTL-DEN
$256

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Last minute flights from St. Louis to Denver

Last minute flight, train and bus deals

 
These last-minute flight deals are the cheapest flights found on KAYAK in the last 72 hours for flights from St. Louis to Denver that are departing in the next 10 days.
4/29Mon
nonstopFrontier
2h 31mSTL-DEN
4/30Tue
multi-stopFrontier
8h 28mDEN-STL
$119
4/29Mon
nonstopFrontier
2h 31mSTL-DEN
4/30Tue
nonstopFrontier
2h 05mDEN-STL
$148
4/29Mon
multi-stopDelta
5h 50mSTL-DEN
4/29Mon
multi-stopDelta
7h 11mDEN-STL
$318
4/26Fri
multi-stop
24h 30mSTL-DEN
4/29Mon
multi-stop
18h 44mDEN-STL
$331
4/26Fri
multi-stop
24h 30mSTL-DEN
5/2Thu
multi-stop
16h 40mDEN-STL
$334
4/25Thu
nonstopUnited Airlines
2h 25mSTL-DEN
5/2Thu
nonstopUnited Airlines
2h 04mDEN-STL
$458
4/26Fri
multi-stopUnited Airlines
5h 31mSTL-DEN
5/2Thu
nonstopUnited Airlines
2h 04mDEN-STL
$467
4/26Fri
multi-stopDelta
5h 06mSTL-DEN
5/1Wed
multi-stopDelta
4h 47mDEN-STL
$492
4/25Thu
multi-stopAlaska Airlines
10h 32mSTL-DEN
4/29Mon
multi-stopAlaska Airlines
16h 14mDEN-STL
$807
4/25Thu
multi-stopAlaska Airlines
10h 32mSTL-DEN
4/29Mon
multi-stopAlaska Airlines
29h 27mDEN-STL
$832

Search by stops

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St. Louis - Denver Flights

Departure:

St. Louis (STL)United States

Destination:

Denver (DEN)United States

Return flight deals:

Denver - St. Louis

Cabin classes:

$607
$1,351
$833
$59

Compare transportation modes for St. Louis to Denver

Average priceAverage duration
Flights$7822h 30m
Buses$20426h 20m