$40 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 3/6. 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

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Everything you should know

Cheapest round-trip
$79
Overall average: $279
Frontier
Sat 3/14Wed 3/18
DEN - STL • Non-stop
Cheapest one-way
$40
Typical prices: $87-$194
Frontier
Fri 3/6
DEN - STL • Non-stop
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Flight Deals
Useful Info
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

Sat, Mar 14 - Wed, Mar 18
Frontier Logo
6:35 am - 9:49 am
DEN
-
STL
2h 14mnonstop
Frontier Logo
8:12 pm - 9:49 pm
STL
-
DEN
2h 37mnonstop
$79Frontier
Fri, Feb 20 - Mon, Feb 23
Frontier Logo
10:01 am - 1:09 pm
DEN
-
STL
2h 08mnonstop
Frontier Logo
1:54 pm - 3:30 pm
STL
-
DEN
2h 36mnonstop
$80Frontier
Wed, Mar 18 - Sat, Mar 21
Frontier Logo
6:35 am - 9:49 am
DEN
-
STL
2h 14mnonstop
Frontier Logo
8:12 pm - 9:49 pm
STL
-
DEN
2h 37mnonstop
$83Frontier
Mon, Mar 2 - Sat, Mar 7
Frontier Logo
12:59 am - 6:51 am
DEN
-
STL
28h 52m
1 stop
Frontier Logo
8:12 pm - 9:49 pm
STL
-
DEN
2h 37mnonstop
$84Frontier
Sat, Feb 28 - Sat, Mar 7
Frontier Logo
7:24 am - 5:46 pm
DEN
-
STL
9h 22m
1 stop
Frontier Logo
8:12 pm - 9:49 pm
STL
-
DEN
2h 37mnonstop
$87Frontier
Fri, Mar 27 - Mon, Mar 30
Frontier Logo
6:35 am - 9:49 am
DEN
-
STL
2h 14mnonstop
Frontier Logo
8:12 pm - 9:49 pm
STL
-
DEN
2h 37mnonstop
$88Frontier
Sat, Mar 28 - Sat, Apr 4
Frontier Logo
6:35 am - 9:49 am
DEN
-
STL
2h 14mnonstop
Frontier Logo
8:16 pm - 9:49 pm
STL
-
DEN
2h 33mnonstop
$93Frontier
Sat, Feb 21 - Mon, Feb 23
Frontier Logo
10:48 am - 1:56 pm
DEN
-
STL
2h 08mnonstop
Frontier Logo
8:47 pm - 7:54 am
STL
-
DEN
12h 07m
1 stop
$107Frontier
Tue, Feb 24 - Fri, Feb 27
Frontier Logo
11:59 pm - 10:27 pm
DEN
-
STL
21h 28m
1 stop
Frontier Logo
1:59 pm - 3:35 pm
STL
-
DEN
2h 36mnonstop
$110Frontier
Wed, Feb 18 - Sat, Feb 21
Frontier Logo
12:48 pm - 3:53 pm
DEN
-
STL
2h 05mnonstop
Frontier Logo
2:51 pm - 4:18 pm
STL
-
DEN
2h 27mnonstop
$111Frontier
Useful Info

Good to know

Low seasonNovember
Cheapest flight$40
Best time to beat the crowds but there is an average 8% increase in price.
Most popular time to fly with an average 4% 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 00m.

  • 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 151 departures each week.

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

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

  • 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.

  • Which airlines provide the cheapest flights from Denver to Belleville?

    In the last 72 hours, the cheapest one-way ticket between Denver and Belleville found on KAYAK was with Frontier for $28. Frontier offered a round-trip connection from $53 and United Airlines from $155.

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 4271 reviews
8.1Boarding
8.0Comfort
7.5Entertainment
8.6Crew
7.0Food
Airline reviews

Flight attendants very hospitable and friendly. Pilot flew a smooth take off and landing.

10.0 ExcellentAnonymous, Feb 2026
MSY - PHX
Read more Southwest reviews

Flight attendants very hospitable and friendly. Pilot flew a smooth take off and landing.

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.

The seats were comfortable, and the boarding process was pretty smooth.

It was rough. The staff was unprofessional, the choice of on board drinks terrible, it was cramped in space at every airport, they always ran out of overhead bin space so they pressured people to check bags for free or we couldn’t leave on the plane— so I did check my bag to help, and they nearly lost my bag. My bag did not arrive on the luggage belt, another man on my flight and I had to waste our time going to the baggage office to search for our bags. I would only fly southwest again if it was my last choice. Also, my flights were consistently delayed over and over again— at one point they straight up told us we were waiting for the pilot to arrive.

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.

Sitting on the runway after we land for almost two hours! Not sure if we should blame United or Just Dumpy Vance.

Flight was late - I was downgraded from first class to coach

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

Good for a budget airline! It was easy to get on, staff was really nice. Can’t say anything about the food or entertainment because it wasn’t available, which is fine.

This company socks. It's fraud. They canceled our flight yesterday, and today we were late because of a really long line at the check in bag. At the rebook station, there was ton of people. The workers were all rude. I am gonna make a report to FTC.

Not clean and was told I would get a great seat and it was not great at all

Delayed. Text notifications were slow. Not much information o what was happening. Boarding was slow and confusing. Wasn’t even offered water other flight. Had to ask. No entertainment at all. Felt like.a Greyhound bus.

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!

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

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