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St. Charles

$66+ Cheap flights from Denver (DEN) to St. Charles, MO

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 1/6. Fares are subject to change and may not be available on all flights or dates of travel.
DEN — STL
Oct 15 — Oct 221
Wed 10/15
Wed 10/22
1 adult, Economy
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Cheapflights Tip: The best prices from Denver Intl to St. Charles are usually found in January or October, booked 74 days in advance, depart on a Friday or Wednesday and return on a Wednesday

Cheap flight deals from Denver to St. Charles

Keep the following information in mind while searching for Denver to St. Charles flight deals. Data was last updated September 15, 2025.

Round-trip from

$96
(Cheapflightsfares)

One-way from

$66
(Southwest)

Popular in

June

Cheapest in

January

Average price

$237
From Denver Intl to St. Charles
Search Deals
One-way flight from Denver Intl to St. Charles
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Highest demand for flights based on searches. 12% potential increase in price ($32 potential increase over avg. RT price).
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Cheapest flight prices on average. 3% potential price decrease ($7 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Find flight deals from Denver to St. Charles

Cheapest flights from Denver to St. Charles
Explore the most affordable flight options available from Denver to St. Charles. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 15, 2025.

This Cheapflightsfares deal was found by Cheapflights users on 9/13. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/56:50 amDEN - STL
Nonstop2h 12mFrontier
Mon 12/87:43 pmSTL - DEN
Nonstop2h 32mFrontier
Deal found 9/13$96
This Priceline deal was found by Cheapflights users on 9/14. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/126:00 amDEN - STL
Nonstop2h 07mFrontier
Fri 11/147:45 pmSTL - DEN
Nonstop2h 28mFrontier
Deal found 9/14$100
This Cheapflightsfares deal was found by Cheapflights users on 9/14. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/86:00 amDEN - STL
Nonstop2h 07mFrontier
Sun 10/127:52 pmSTL - DEN
Nonstop2h 28mFrontier
Deal found 9/14$101
This Frontier deal was found by Cheapflights users on 9/13. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/26:00 amDEN - STL
Nonstop2h 06mFrontier
Sun 10/57:55 pmSTL - DEN
Nonstop2h 25mFrontier
Deal found 9/13$105
This Cheapflightsfares deal was found by Cheapflights users on 9/13. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/2912:59 amDEN - STL
1 stop8h 13mFrontier
Mon 11/37:45 pmSTL - DEN
Nonstop2h 28mFrontier
Deal found 9/13$108
This Priceline deal was found by Cheapflights users on 9/14. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/1212:59 amDEN - STL
1 stop8h 13mFrontier
Sun 11/167:45 pmSTL - DEN
Nonstop2h 28mFrontier
Deal found 9/14$109
This Priceline deal was found by Cheapflights users on 9/14. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/118:00 amDEN - STL
1 stop6h 56mFrontier
Tue 10/147:52 pmSTL - DEN
Nonstop2h 28mFrontier
Deal found 9/14$112
This Flightnetwork deal was found by Cheapflights users on 9/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Flightnetwork is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/236:00 amDEN - STL
Nonstop2h 07mFrontier
Mon 10/279:59 pmSTL - DEN
1 stop23h 06mFrontier
Deal found 9/15$113
This Cheapflightsfares deal was found by Cheapflights users on 9/13. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/296:00 amDEN - STL
Nonstop2h 06mFrontier
Mon 10/62:38 pmSTL - DEN
1 stop22h 43mFrontier
Deal found 9/13$114
This Cheapflightsfares deal was found by Cheapflights users on 9/14. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/3012:16 amDEN - STL
1 stop12h 01mFrontier
Sun 11/27:45 pmSTL - DEN
Nonstop2h 28mFrontier
Deal found 9/14$115
This Priceline deal was found by Cheapflights users on 9/13. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/1312:16 amDEN - STL
1 stop9h 04mFrontier
Sun 11/167:45 pmSTL - DEN
Nonstop2h 28mFrontier
Deal found 9/13$116

Cheapflights Fare Finder

 
Customize your flight search to find flights from Denver to St. Charles 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, Cheapflights users made 2,558,603 searches. Data last updated September 15, 2025.
Use the filters below to find and compare flights from Denver to St. Charles that are best for you.

Fly from

Denver

Fly to

St. Charles

Route

Depart

Return

Price

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Thu 10/16

6:00 am-9:07 am

Nonstop2h 07m

Lambert-St Louis

Mon 10/20

7:52 pm-9:20 pm

Nonstop2h 28m

$101

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Wed 11/12

10:29 pm-1:57 pm

1 stop14h 28m

Lambert-St Louis

Sat 11/15

7:45 pm-9:13 pm

Nonstop2h 28m

$113

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Mon 10/13

6:00 am-9:07 am

Nonstop2h 07m

Lambert-St Louis

Thu 10/16

10:17 am-8:55 pm

1 stop11h 38m

$121

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Fri 10/10

8:45 pm-11:58 pm

Nonstop2h 13m

Lambert-St Louis

Sun 10/12

5:15 am-6:53 am

Nonstop2h 38m

$131

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Fri 12/26

7:13 pm-10:22 pm

Nonstop2h 09m

Lambert-St Louis

Sat 1/3

2:45 pm-4:21 pm

Nonstop2h 36m

$131

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Wed 11/12

10:15 am-1:20 pm

Nonstop2h 05m

Lambert-St Louis

Sat 11/15

12:20 pm-5:50 pm

2 stops6h 30m

$146

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Sat 10/25

12:10 pm-5:10 pm

1 stop4h 00m

Lambert-St Louis

Sun 10/26

5:35 am-7:00 am

Nonstop2h 25m

$153

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Tue 12/23

6:15 pm-12:05 am

1 stop4h 50m

Lambert-St Louis

Thu 1/1

8:15 pm-9:35 pm

Nonstop2h 20m

$154

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Sat 11/22

5:40 pm-12:15 am

1 stop5h 35m

Lambert-St Louis

Sun 11/23

6:40 pm-11:50 pm

1 stop6h 10m

$167

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Fri 10/31

3:39 pm-3:56 pm

2 stops23h 17m

Lambert-St Louis

Sun 11/2

7:45 pm-9:13 pm

Nonstop2h 28m

$170

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/14

Showing 1-10 of 18 results
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Best time to book a flight from Denver to St. Charles

Have a flexible travel schedule? Discover the best time to fly to St. Charles from Denver with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Denver to St. Charles

How far ahead should I book a flight from Denver to St. Charles?

Use this chart to determine the optimal time to book a round-trip flight from Denver to St. Charles. Price data was last updated on September 12, 2025.

To ensure you get the cheapest price possible for a flight from Denver to St. Charles, you should look to book at least 74 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

What is the cheapest month to book a flight from Denver to St. Charles?

Currently, August is the cheapest month in which you can book a flight from Denver to St. Charles (average of $311). Flying from Denver to St. Charles in March is currently the most expensive (average of $356). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from DEN to CH5?

Find hourly flight availability from Denver to St. Charles. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated September 15, 2025.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Denver to St. Charles as you normally would.

What is the cheapest day to fly from Denver to St. Charles?

Use this chart to determine the cheapest time to fly round-trip from Denver to St. Charles. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Denver to St. Charles flight should consider departing on Friday evenings when fares are most often at their lowest. Monday afternoons flights should be avoided if possible as fares are typically the most expensive at this time.

Weekly flight availability from Denver to St. Charles

Explore weekly flight availability from Denver to St. Charles. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated September 15, 2025.

The most flights from DEN to CH5 are scheduled on a Monday (17 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (8 on average).

Reviews of airlines servicing St. Charles

Get insights into the airlines that provide service to St. Charles. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to St. Charles. Reviews last updated September 15, 2025.
See what other customers who have flown with Southwest, United Airlines, and Frontier from Denver to St. Charles have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,242 reviews

Comfort

8.0

Overall

8.0

Food

7.0

Boarding

8.1

Crew

8.6

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines
Southwest
8.0
Very good
4,242 reviews
Southwest
8.0
Very good
4,242 reviews

Comfort

8.0

Overall

8.0

Food

7.0

Boarding

8.1

Crew

8.6

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines
United Airlines
7.4
Good
8,929 reviews
Southwest
8.0
Very good
4,242 reviews

Comfort

8.0

Overall

8.0

Food

7.0

Boarding

8.1

Crew

8.6

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines
Frontier
5.8
Fair
3,172 reviews
Southwest
8.0
Very good
4,242 reviews

Comfort

8.0

Overall

8.0

Food

7.0

Boarding

8.1

Crew

8.6

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Mike,Aug 2025

OKC - AUS

AC was not adequate, even on a night flight. WiFi subpar even for the airlines

Related info for your journey

Find useful and relevant information for your journey from Denver to St. Charles. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly from for flights from Denver to St. Charles?

    Denver Intl (DEN), located 18.5 mi from the city center, is the airport you fly out of when you book flights from Denver to St. Charles. 4 airlines have flights from Denver Intl to St. Charles on a regular basis. Booking flights from Denver Intl to St. Charles should not be difficult; the airport handles an average of 13 outbound flights to St. Charles per day.

  • How popular is this Denver to St. Charles flight route?

    The Denver Intl to St. Charles flight path was viewed by 29 users in the past month. Keep an eye out for changes in search interest prior to high and low season.

  • How long is the flight from Denver to St. Charles?

    For as low as $101, Frontier can have you in St. Charles from Denver in 2h 07m. Airlines will cover a distance of 767 mi. Generally, flights for this route are nonstop.

  • What are the most reliable airlines from Denver to St. Charles?

    The top 3 most reliable airlines when flying from Denver to St. Charles are Frontier (85%), Air Canada (67%) and United Airlines (65%).

  • What are the cheapest flights from Denver to St. Charles?

    While on average a flight from Denver to St. Charles is generally $209, our data shows the cheapest flight currently is $77. When looking at the most popular route, (Denver Intl - Lambert-St Louis), you can expect to pay $131 for that flight.

  • Can I find deals for flights from Denver to St. Charles that include hotel bookings?

    Yes. In addition to deals on Denver to St. Charles flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Denver to St. Charles?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Denver to St. Charles.

  • Can I find deals for business class flights from Denver to St. Charles?

    Yes. Cheapflights offers flight deals from Denver to St. Charles by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Denver to St. Charles?

    Currently, August is the cheapest month in which you can book a flight from Denver to St. Charles (average of $311). Flying from Denver to St. Charles in March is currently the most expensive (average of $356). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

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Alternative routes for Denver to St. Charles

See prices for flight routes from nearby airports that may be better suited for you.
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Top 4 airlines flying from Denver to St. Charles

Discover the top 4 airlines that operate flights from Denver to St. Charles. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated September 15, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$57Average$158FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$154Average$299FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$173Average$297FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$354Average$481FlexibilityNo cancel feeOn-time71%

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