$36 Find Cheap Flights from Denver to Belleville

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 Belleville departing on 1/21. 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

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Flight Deals

Cheap Flights from Denver to Belleville (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 Belleville 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 Denver to Belleville

Thu, Oct 30 - Mon, Nov 3
Frontier Logo
6:00 am - 9:07 amDEN-STL
2h 07mnonstop
Frontier Logo
2:12 pm - 11:16 pmSTL-DEN
10h 04m1 stop
$98Frontier
Find Deal
Mon, Nov 10 - Mon, Nov 17
Frontier Logo
6:00 am - 9:07 amDEN-STL
2h 07mnonstop
Frontier Logo
2:42 pm - 3:59 amSTL-DEN
14h 17m1 stop
$99Frontier
Find Deal
Thu, Oct 30 - Mon, Nov 3
Frontier Logo
8:32 am - 5:27 pmDEN-STL
7h 55m1 stop
Frontier Logo
7:45 pm - 9:13 pmSTL-DEN
2h 28mnonstop
$100Frontier
Find Deal
Mon, Oct 27 - Thu, Oct 30
Frontier Logo
6:00 am - 9:07 amDEN-STL
2h 07mnonstop
Frontier Logo
8:40 pm - 10:10 pmSTL-DEN
2h 30mnonstop
$101Frontier
Find Deal
Fri, Dec 12 - Mon, Dec 15
Frontier Logo
6:50 am - 10:02 amDEN-STL
2h 12mnonstop
Frontier Logo
7:43 pm - 9:15 pmSTL-DEN
2h 32mnonstop
$103Frontier
Find Deal
Fri, Nov 7 - 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
$105Frontier
Find Deal
Sat, Nov 1 - Sat, Nov 8
Frontier Logo
6:00 am - 9:07 amDEN-STL
2h 07mnonstop
Frontier Logo
4:33 pm - 11:16 pmSTL-DEN
7h 43m1 stop
$107Frontier
Find Deal
Wed, Nov 5 - Mon, Nov 10
Frontier Logo
12:59 am - 10:12 amDEN-STL
8h 13m1 stop
Frontier Logo
9:07 pm - 3:59 amSTL-DEN
7h 52m1 stop
$108Frontier
Find Deal
Sat, Nov 15 - Tue, Nov 18
Multiple Airlines Logo
12:25 pm - 5:16 pmDEN-STL
27h 51m2 stops
Multiple Airlines Logo
7:45 pm - 9:13 pmSTL-DEN
2h 28mnonstop
$157Multiple Airlines
Find Deal
Sat, Nov 8 - Tue, Nov 11
Multiple Airlines Logo
12:25 pm - 5:16 pmDEN-STL
27h 51m2 stops
Multiple Airlines Logo
7:45 pm - 9:13 pmSTL-DEN
2h 28mnonstop
$159Multiple Airlines
Find Deal

Everything you should know

Cheapest round-trip
$98
Typical prices: $145-$320
Frontier
Thu 10/30Mon 11/3
DEN - STL • Non-stop
Cheapest non-stop
$101
Typical prices: $135-$327
Frontier
Mon 10/27Thu 10/30
DEN - STL • Non-stop
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We hope you love your trip to Belleville!
Useful Info

Good to know

Low seasonJanuary
Cheapest flight$36
Best time to beat the crowds with an average 27% drop in price.
Most popular time to fly with an average 1% increase in price.
Flight from Denver to St. Louis

When to book flights from Denver to Belleville

Are your dates flexible? Find out the best times to travel from Denver to Belleville 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 Belleville

  • Which airports will I be using when flying from Denver to Belleville?

    When flying out of Denver you’ll be using Denver Intl. Belleville does not have its own airport so you’ll be flying into nearby Lambert-St Louis airport, which is 26.3 mi away.

  • How long does a flight from Denver to Belleville take?

    Direct flights cover the 767 miles separating Denver and Belleville in about 2h 07m.

  • How many flights are there between Denver and Belleville?

    21 direct flights run between Denver and Belleville on a daily basis. On average, there are about 150 departures each week.

  • What’s the cheapest day of the week to fly between Denver and Belleville?

    Consider leaving on a Thursday and avoid Fridays if you are looking for the best rates. For your return to Denver, you’ll find the best rates on Wednesdays and the most expensive ones on Fridays.

  • How does KAYAK find such low prices on flights from Denver to Belleville?

    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 Belleville.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Belleville 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 Belleville?

    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 Belleville 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 Belleville?

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

Top tips for finding cheap flights from Denver to Belleville

  • There is no airport in Belleville. Instead, you’ll be flying into St. Louis Lambert Airport when flying between Denver and Belleville.
  • The cheapest flight from Denver to Belleville was found 74 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 May, June and July. The cheapest month to fly is January.

Reviews of the top 3 airlines serving Denver to Belleville

 
Need help choosing which airline to fly with from Denver to Belleville? 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 4235 reviews
8.6Crew
7.0Food
8.0Comfort
7.5Entertainment
8.1Boarding
Airline reviews

Connecting flight is on time and boarding was a breeze!

10.0 ExcellentGabriel, Sep 2025DEN - SMF
Read more Southwest reviews

Connecting flight is on time and boarding was a breeze!

Excellent. Would encourage Southwest to keep current boarding procedures with free style seating. Makes for a fantastic experience

WiFi did not work. For as outrageous as these flights cost, when they’re advertised with certain services/ features they should be in working order

Worst experience I had on Southwest. Still better than most, but the seating was barely tolerable.

It was okay. The plane was delayed from earlier in the day, but they kept updating the departure time, sometimes later, sometimes earlier. That was stressful. Once we finally got on and took off, it was fine. I was supposed to have a connection in Chicago to Los Angeles, and the time for so late I was rebooked to arrive in LA 3 hours late. The departure time to Chicago later became early enough to have taken my original connection and arrive earlier but that wasn't an option.

Everything was on time. I was disappointed by the front section female, African American flight attendant. I did not see her name tag or would have identified by name not race. As passengers moved to the bathroom early in flight, she would say with a disdainful tone “I have to say the seat belt light is on” then go back to her book. Better trained flight attendants say something like be careful the seat belt light is on.

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!

Flight was awfully bumpy and landing was a bit jolting. I was in the restroom when snacks and drinks were served and was not asked if i wanted any. I had to ask for water finally.

Crew seemed a bit cranky. No seatback screens. But boarding was efficient and on time and we arrived early.

See previous note about the passenger in Denver who threw my husband's bag out of the overhead bin in order to maker room for his own. And the flight attendant back up the new passenger.

Terrible. They wouldn't allow me on my flight on the 14th..

Impressed with the service despite turbulence because of the weather. Both flights arrived before their scheduled times.

Great experience…left a bit behind schedule but made up fir that in the air and landed 10 minutes early 😁

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

The single worst check in experience I could imagine. I’ll never do any business with Frontier or any affiliated company

Too many extra fees, uncomfortable, little leg room. Will not recommend this airline.

Frontier is the Walmart of airlines. Frontier has removed adjustability and comfort from their seats to make the flight lighter and save gas. This makes it impossible to sleep on their flights. Their customer service is abysmal. Once, I bought a drink on the plane, and they swiped my credit card on the plane to pay for it. Then I got three weeks of daily notices from my bank telling me they tried to charge the wrong card number over and over again. I tried to call them, but they removed the ability to actually talk to someone that can resolve such a problem from their company to cut corners. The only way to talk to someone in person is to go to the check-in counter at the airport (40 minutes drive from my house). Eventually their system gave up on trying to charge the card, after 21 days of repeated tries. They don't pad their prices even a little to handle customer service issues like missed flights. They also have a blanket policy preventing helping you reschedule a missed flight if their system says you "cancelled" your own flight online. This is a major problem because their website is broken on mobile devices, the only web browser you have at the airport when their gate staff tell you that you have to reschedule your own missed flight online because they can't help you. I tried to reschedule my flight on my android device and instead, their website crashed and "cancelled" my missed flight. When I got to the counter, the agent argued with me for 5 minutes insisting that I intentionally cancelled my own flight (implying I had to buy another flight). She missed the point: the problem was that I could not buy another flight because their website is broken. I left to avoid more conflict with the "customer service" agent. I tried to redress my issue with their only other "customer service" chanel available: the contact form on their website. The response I got was more of the same: you cancelled your own flight, according to our website / computer records, therefore we won't help you. I was trying to explain the problem with their broken website that cost me hundreds of dollars by crashing / malfunctioning and resulting in a cancelled flight, but they only had deaf ears for this problem. Worst customer service I have ever experienced. I will never buy another Frontier flight again, because it is a risky, painful move that I will likely regret often.

What I expected, nickeled and dined and a frontier flight attendant loudly complained about her job and lack of communication as she headed to the gate on her cell phone. Not professional.

Severe turbulence. Captain never came on to reassure passengers after things settled down.

I’m not gonna fly Frontier Airlines because booking is not an option. No water or food is for high price, not equipped for health emergency incompetent crew for emergency services. Cheap airline shows it is cheaper in all service categories. Boarding is the best of all airlines!

We were delayed three times ,and that destroyed my plans, and reservations

Very bad! No good service delayed my second connection flight

Frontier is terrible. Paid for exit row, not given exit row, refused to refund fee.

2 hour delay due to late plane, wrong size plane causing overbooking, and people getting off and on the plane after boarding was completed.

Everything you need to know for your flight from Denver to Belleville

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