STL - DEN

$28 Find Cheap Flights from St. Louis to Denver

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 2/28. 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
1 adult, Economy, 0 bags

KAYAK searches 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
Travelers love KAYAK
41,299,237 searches in the past 7 days on KAYAK

Save 23% or moreCompare multiple travel sites with one search.

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

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

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

Everything you should know

Cheapest round-trip
$67
Overall average: $197
Frontier
Sat 2/7Wed 2/11
STL - DEN • Non-stop
Cheapest one-way
$28
Typical prices: $57-$186
Frontier
Sat 2/28
STL - DEN • Non-stop
Our travelers' advice
AI-powered summary based on content written by travel experts. AI can make mistakes.
Southwest offers two free checked bags on this route.
Avoid peak hours at STL to minimize wait times.
Expert advice
Expert advice
Expert advice
Expert advice
Video guide: How to find cheap flights to Denver
Watch video
Watch video
Watch video
Watch video
When to book
2 weeks
in advance
Our data shows that travelers who book at least 2 weeks in advance save around 17% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
October
Cheapest • 23% price drop
March
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
Start a new search
KAYAK searches 100s of sites at once to find you the best travel deals.
We hope you love your trip to Denver!
Flight Deals
Booking Insights
Expert advice
Flight Deals

Cheap Flights 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 for you by selecting your travel dates on KAYAK.

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

Sat, Feb 7 - Wed, Feb 11
Frontier Logo
3:46 pm - 5:23 pm
STL
-
DEN
2h 37mnonstop
Frontier Logo
10:50 am - 1:58 pm
DEN
-
STL
2h 08mnonstop
$67Frontier
Sat, Feb 7 - Wed, Feb 11
Frontier Logo
3:46 pm - 5:23 pm
STL
-
DEN
2h 37mnonstop
Frontier Logo
10:50 am - 1:58 pm
DEN
-
STL
2h 08mnonstop
$68Frontier
Sat, Feb 21 - Wed, Feb 25
Frontier Logo
2:51 pm - 4:18 pm
STL
-
DEN
2h 27mnonstop
Frontier Logo
12:48 pm - 3:53 pm
DEN
-
STL
2h 05mnonstop
$71Frontier
Sat, Feb 21 - Wed, Feb 25
Frontier Logo
2:51 pm - 4:18 pm
STL
-
DEN
2h 27mnonstop
Frontier Logo
12:48 pm - 3:53 pm
DEN
-
STL
2h 05mnonstop
$72Frontier
Sat, Feb 14 - Wed, Feb 18
Frontier Logo
2:51 pm - 4:18 pm
STL
-
DEN
2h 27mnonstop
Frontier Logo
12:48 pm - 3:53 pm
DEN
-
STL
2h 05mnonstop
$76Frontier
Fri, Feb 27 - Mon, Mar 2
Frontier Logo
1:59 pm - 3:35 pm
STL
-
DEN
2h 36mnonstop
Frontier Logo
10:01 am - 1:09 pm
DEN
-
STL
2h 08mnonstop
$80Frontier
Wed, Feb 4 - Sat, Feb 7
Frontier Logo
3:46 pm - 5:23 pm
STL
-
DEN
2h 37mnonstop
Frontier Logo
11:38 am - 2:46 pm
DEN
-
STL
2h 08mnonstop
$83Frontier
Sat, Feb 28 - Sat, Mar 7
Frontier Logo
2:51 pm - 4:18 pm
STL
-
DEN
2h 27mnonstop
Frontier Logo
6:35 am - 9:49 am
DEN
-
STL
2h 14mnonstop
$85Frontier
Sun, Feb 8 - Wed, Feb 11
Frontier Logo
12:03 pm - 1:36 pm
STL
-
DEN
2h 33mnonstop
Frontier Logo
10:50 am - 1:58 pm
DEN
-
STL
2h 08mnonstop
$87Frontier
Sat, Feb 21 - Sat, Feb 28
Frontier Logo
2:51 pm - 4:18 pm
STL
-
DEN
2h 27mnonstop
Frontier Logo
10:48 am - 1:56 pm
DEN
-
STL
2h 08mnonstop
$88Frontier
Booking Insights

KAYAK's insights & trends for St. Louis to Denver flights

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.

Find cheap flights to Denver
Find cheap flights to Denver

Planning a trip from St. Louis to Denver? KAYAK’s data-powered insights will help you find cheap flights. Learn the best time to fly, how early to book your ticket, and other tips to secure great prices.

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

The average price of all round-trip flights from St. Louis to Denver clicked on KAYAK for each day over the last 12 months.

For St. Louis to Denver, Wednesday is the cheapest day to fly on average and Sunday is the most expensive. Flying from Denver back to St. Louis, the best deals are generally found on Friday, with Sunday being the most expensive.

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 round-trip 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 $177 (return) on average. On the other hand, the most expensive months are March and July, where the average cost of round-trip tickets is $336 and $282 respectively.

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

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip 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 week.

To get a below average price on the flight from St. Louis to Denver, you should book around 2 weeks before departure, which saves you about 17% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 11 weeks before departure.

Expert advice

Expert advice for your flight from St. Louis to Denver

 
AI-powered summary based on content written by travel experts. AI can make mistakes.
KAYAK teamed up with top travel experts to share the best tips for your journey.
Our travel experts
Stefanie Waldek

Stefanie Waldek

Expert on Frontier and United Airlines

Stefanie Waldek is a freelance space, travel, and design writer based in Saratoga Springs, NY. Her words have appeared in Space.com, Travel + Leisure, Condé Nast Traveler, Architectural Digest, and House Beautiful, among other publications. An expert in aviation and expedition cruising, Stefanie is frequently up in the air or on the sea, likely en route to Antarctica or the Arctic.

Blane Bachelor

Blane Bachelor

Expert on Southwest

Blane Bachelor is a journalist and editor specializing in travel and aviation who writes regularly for top global outlets. Born and raised in Florida, Blane has worked and lived in four countries, including the Netherlands, where she’s currently based with her family. Her favorite way to get to know a new destination is by running or riding a bike around town – or hearing a spooky ghost story about local history. She will always choose the window seat.

Yulia Denisyuk

Yulia Denisyuk

Expert on STL

Yulia is a freelance journalist who’s dispatched from 90+ countries. Her work focuses on cultures, adventure trips and air travel, appearing in NatGeo, NYT, CNTraveler, and more. For past assignments, she’s stayed with nomads in Mongolia and learned the art of Imigongo in Rwanda. She’s based in Chicago; in winter she often questions that decision.

Harriet Baskas

Harriet Baskas

Expert on DEN

Harriet is an award-winning journalist who is happiest in an airport or an unusual museum. Her stories about airports, air travel, and the business of travel have appeared on NBC News, CNBC, USA TODAY, The Points Guy and other outlets. She is the creator of the StuckatTheAirport.com blog and the author of nine books. When not out on the road or exploring the latest airport amenities, she’s home in Seattle getting ready for the next adventure.

Good to know

Low seasonDecember
Cheapest flight$28
Best time to beat the crowds but there is an average 4% increase in price.
Most popular time to fly with an average 45% 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 $28 for a one-way ticket and $67 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, JetBlue, Delta, and Hawaiian 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 Boeing 737 MAX 8 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?

    oneworld, SkyTeam, and Star Alliance are the airline alliances operating flights between St. Louis and Denver, with oneworld being the most commonly used for this route.

  • 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, Southwest or Delta?

    The two airlines most popular with KAYAK users for flights from St. Louis to Denver are Southwest and Delta. With an average price for the route of $299 and an overall rating of 8.0, Southwest is the most popular choice. Delta is also a great choice for the route, with an average price of $326 and an overall rating of 7.9.

  • 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.

KAYAK’s top tips for finding a cheap flight from St. Louis to Denver

  • Looking for a cheap flight? 25% of our users found flights on this route for $147 or less one-way and $236 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.

Prefer to fly direct from St. Louis to Denver?

 
Direct data is based off flight results for the next 60 days. Find direct flights from all airlines flying direct from Lambert-St Louis to Denver Intl.
Find which airlines fly direct from Lambert-St Louis Airport to Denver Intl Airport, which days they fly and book direct flights.

Direct departures

Lambert-St Louis to Denver Intl

Monday

Frontier, Southwest, United Airlines

Frontier, Southwest, +1 more

Tuesday

Southwest, United Airlines

Southwest, United Airlines

Wednesday

Frontier, Southwest, United Airlines

Frontier, Southwest, +1 more

Thursday

Southwest, United Airlines

Southwest, United Airlines

Friday

Frontier, Southwest, United Airlines

Frontier, Southwest, +1 more

Saturday

Frontier, Southwest, United Airlines

Frontier, Southwest, +1 more

Sunday

Frontier, Southwest, United Airlines

Frontier, Southwest, +1 more

See more direct flights

Direct returns

Denver Intl to Lambert-St Louis

Monday

Frontier, Southwest, United Airlines

Frontier, Southwest, +1 more

Tuesday

Southwest, United Airlines

Southwest, United Airlines

Wednesday

Frontier, Southwest, United Airlines

Frontier, Southwest, +1 more

Thursday

Southwest, United Airlines

Southwest, United Airlines

Friday

Frontier, Southwest, United Airlines

Frontier, Southwest, +1 more

Saturday

Frontier, Southwest, United Airlines

Frontier, Southwest, +1 more

Sunday

Frontier, Southwest, United Airlines

Frontier, Southwest, +1 more

See more direct flights

Reviews of the top 5 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
SouthwestOverall score based on 4268 reviews
8.1Boarding
8.6Crew
8.0Comfort
7.0Food
7.5Entertainment
Airline reviews

All good except once again bags took an hour at Midway Airport Happens all the time. Ridiculous

10.0 ExcellentAnonymous, Jan 2026
PHX - MDW
Read more Southwest reviews

All good except once again bags took an hour at Midway Airport Happens all the time. Ridiculous

Everything went smoothly and we even arrived a little bit early.

Great vacation. Can't wait till next year for another one.

Pretty seamless, just a tad bit late in taking off and landing.

Everything a cheap airline should be at normal airline rates.

Sacrament staff are always polite and helpful. Airport is easy to maneuver and boarding is straightforward.

Delays delays delays. Late taking off, late landing, wait for a gate, etc.

Near 4 hour flight with only 1 service. Had to use call button to request water. Internet and power not working until into flight. Internet would stop working during flight.

The Southwest employees (all two of them) were very nice and cheerful despite the fact the line to self-check a bag (simply drop it off) was hundreds of people long. Thank God I arrived early to the airport because I stood in this line for at least an hour. Once on the flight that had been delayed by an hour, we had no Wi-Fi and thus no entertainment. Finally, I hope the investor strong arm tactics against Southwest pay off in a short-term windfall to your C-Suite because the rest of you are screwed. I have been a faithful Southwest customer for 15 years due to everything you just got rid of. I'm flying to Idaho and Washington in October, both places I used to simply book with Southwest without a second thought now with Frontier (Washington) and United (Idaho) because they offer everything the "new" Southwest does but cheaper and at better times, destinations, etc. This really makes me sad...

Flights delayed by 4-6 hours. Boarding was a mess and unclear. Bags were not at arrival airport and had never even been put on the plane. No idea when I’ll get them. Don’t fly into Denver!

The service from the flight attendants were of supreme quality. They greeted and treated everyone with a wide smile. This is totally absent nowadays. Kudos to them!!!!

Excellent flight and got us around tough weather. Only issue was seat TV did not work and crew tried to reboot.

Very large passenger too space from my own seat. Arm board couldn’t be lowered because of his size. It wads very uncomfortable trip, as the flight was full couldn’t move anywhere having back pain because of the position in which I was the entire flight.

was sitting in the jet bridge for 10 minutes in -20 degree weather waiting for my bag

Outdated equipment in disrepair, wifi inoperable. Broken seats, taped air vents, generally poor condition, the 717 showed its age and lack of upkeep.

My flight out of Baton Rouge to Atlanta was delayed by a half hour. This got us into Atlanta airport 30 minutes late. I ran through the airport to get to my connecting flight. As I approached the boarding gate, I saw the boarding door was still open and a passenger was being checked in. But when I got to the gate, the boarding agent told me they had already given away my seat and there were no empty seats on that flight. So I had to take a later flight. That has never happened to me before. Very frustrating.

Connection through Atlanta was difficult. Mechanical issue on plane caused a two hour delay. New gate was a mile away.

No WiFi. Comfort plus should have alcohol provided, crew only offered water or tea. Who the heck wants tea?

The flight was delayed and oversold. I volunteered to give up my seat for compensation. Thinking I could get a good night's sleep instead of arriving home at 2 am. It took over an hour to get the new reservation confirmed, three different gate attendants, and two red coats. It took even longer to confirm the overnight hotel, and when I arrived, the line was 45 minutes long, with two people checking in, and at least 15 people slowly, very slowly—no food except frozen convenience food, no coupon for food from airlines. Slept, headed back to the airport, and that flight had an equipment change and a gate change just as they were about to board. It took an additional hour to board as they cleaned the plane from storage.

There was no wifi available on this flight. And there were no screens, no onboard entertainment, no entertainment options at all. It was like travelling in the 1990s again, except without even a main screen for options. Seats, as usual, were tight and uncomfortable.

The flight was delayed by two de-icings. The seatbelt did not work correctly. It did not stay tight.

Hotter than Hades in August. Why, why do crews think that in the winter when we are already dressed for cold weather we need a cabin that is 82 degrees. Even the vents were blowing hot air.

Flight was delayed. De-icing took a while. When we landed had to wait for another plane to vacate our gate. Just an overall bad experience.

Not good - outbound flight was delayed and missed my connection even though I got to the gate after running through the airport - the agent would not let me on because the door was closed (flight had not left). There was no notification from United - overall experience was very disappointing. Additionally, I was downgraded from first class to coach on the alternative flight

United have really come back. Airport and boarding process is clear and good, app and information also very good

The entertainment available didn’t work for anyone on the flight. Long 6 hr flight with no entertainment option and the staff didn’t know until an hour into the flight when we made sure they knew about it. They had no way to fix it.

Late FA meant slow boarding. WiFi did not work. I’m a medium plus sized passenger. The seatbelt was for the first time ever barely fitting. And we delayed on the tarmac 40 min

My husband and I had boarded the flight from Denver to Chicago, and one of the last passengers to get on the plane opened the overhead bin above my husband's seat and threw his bag out of the bin to make space for his own. He said, "Mine is bigger!" The flight attendant supported the new passenger. They didn't care that my husband has two artificial knees and must have the foot room in front of his seat to be able to fit his legs in -- and to be able to stand, much less walk, at the end of the flight. I have never seen this happen before, and it was a disaster.

I understand stuff happens, but plane failures are likely due to lack of maintenance. Additionally, air conditioning wasn't working, no snack/drink service, no WiFi. Fortunately, the crew was communicative and light-hearted. United grabbed another plane and we were able to get to our destination.

Had to cancel first flight because Airporter Bus took over 3 hrs to get to airport which resulted in an extra $378 dollar fare . Is there anyway I can be reimbursed for initial fare since it was not my fault? Sent from my iPhone EJ Ledet

The flight attendant use 1.5 hours to answer my call. My dirty food tray was unattended.

The attendants were kind and helpful. A sugar-free drink would have been very welcome.

Pilot navigated severe weather/snow storm with skill. Described his intentions clearly

one crew said "he" didn't serve double alcohol drinks for travelers in exit rows. crew on prior flight did. Is this a AA rule, and the prior crew was being nice? Also, I think we deserve more than a 25% refund for losing first class seats when rescheduling a flight due to weather

It was a little concerning to hear the ground crew arguing with the flight crew over baggage space. Instead of taking them and checking them, they started checking for space in the first class cabin moving items around like the flight crew didn't know what they were doing. I was embarrassed for them.

2 hour delay due to equipment failure. No updates via the app and airport screens (which continued to show a departure time in the past). AA eventually switched planes and the new plane was not catered or cleaned correctly.

I booked an aisle seat and was given a middle. At 6'4" 230lbs, it is not ideal to fly in the middle row for myself and passengers.

Trip delayed for 2 hours because of rain. We boarded and have to get down the flight and reboard again.

The aircraft had several problems - from excess fuel to non operational ac. Two hours of delay in Chicago could have been avoided with proper planning and aircraft maintenance.

This flight captain and crew were amazing, started ahead of time of departure and reached 30 mins before arrival time. Amazing!

It was costly and difficult to check in. $85 to take a small suitcase with me, carry on or checked and $75 on the return trip, Plus $25 if I didn't check my self in check in $25, because I couldn't do it on the kiosk. Small very uncomfortable seats, waited on the runway for near an hour each way. It was my worst flight to date.

Due to weather, my flight was delayed, further delayed, then canceled. I eventually got through to a support person who helped me find a different route out of MSP, but to get to DIA, they didn't want to, but eventually did help with the connection ticket purchase. But even this replacement flight was delayed time and time again, and I would have missed my connecting flights and I didn't want to get stuck in a layover city, so after 12 hours at the airport with two young boys who were very tired, we just cancelled our plans and spent the week at home, instead of Nana's.

I knew going into this that Frontier, being a low cost carrier, would be pretty bare bones and charge for most extras but this was made up for by the fact that the airplane was a reasonably new Airbus, every employee was great and best of all, Everett Washington is an amazing airport - thanks Frontier for flying there!!!

Seats were new and comfortable. Staff was fine. Missed my connection due to weather -which wasn’t their fault- but got no help at all. Gate staff sent me to customer service, which was and stayed unstaffed. Sign with QR code directed me to call or chat. Chat was useless. Call was returned after an hour. No itinerary offered by Frontier could get me home in less than 30 hours. Rebooked with another airline and got a partial refund that came to about 10 percent of what I paid to get home.

The experience was good. No frills but I got there safe and sound and on time.

As every law enforcement agency I could imagine surrounded the plane and we didn’t disembark for 2 hours and then had to stick around for another hour to go get our personal belongings after leaving them behind and being bused away from the plane, it was scary and inconvenient. We were given no information as to why this was happening. Lack of communication with passengers was disappointing.

Frontier Airlines was AWFUL. I was an hour early for my flight and the lady refused to check me in. I had to purchase a whole new ticket with a different airline.

Late, terrible communication, horrible planning of passenger seating until the literal last minute. One of the worst flying experiences of my life. Y'all suck

First of all, we never got on the connecting flight to Denver. They delayed our flight for two hours. If we would have gotten on that flight, we would have been stuck in Denver for 13 hours. So we re- routed our flight for a straight through flight to Oklahoma two days later. THEN, they delayed that flight for two hours. After that we were able to finally get on our flight and come home. Frontier Airlines - one of the worst airlines I have ever been on.

Terrible communication with weather delay, lost baggage, near impossible to reach customer service

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

Other airlines flying from St. Louis to Denver

Flights from the other most popular airlines that fly from St. Louis to Denver according to KAYAK users. Prices are the lowest found on KAYAK over the last 7 days. Price and availability are not guaranteed.