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St. Charles

$151+ Cheap flights from Boston (BOS) 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 8/21. Fares are subject to change and may not be available on all flights or dates of travel.
BOS — STL
Aug 5 — Aug 121
Tue 8/5
Tue 8/12
1 adult, Economy
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Cheapflights Tip: The best prices from Boston Logan Intl to St. Charles are usually found in August or September, booked 63 days in advance, depart on a Wednesday or Thursday and return on a Thursday

Cheap flight deals from Boston to St. Charles

Keep the following information in mind while searching for Boston to St. Charles flight deals. Data was last updated July 31, 2025.

Round-trip from

$242
(CheapOair)

One-way from

$151
(Mytrip)

Popular in

April

Cheapest in

August

Average price

$473
From Boston Logan Intl to St. Charles
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One-way flight from Boston Logan Intl to St. Charles
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Highest demand for flights based on searches. 8% potential increase in price ($40 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($7 potential savings vs. average RT price).
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Average for round-trip flights in July 2025
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Find flight deals from Boston to St. Charles

Cheapest flights from Boston to St. Charles
Explore the most affordable flight options available from Boston to St. Charles. Find the lowest fares from popular airlines and budget airlines, with prices last updated on July 31, 2025.

This CheapOair deal was found by Cheapflights users on 7/29. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/156:30 amBOS - STL
1 stop8h 02mMultiple Airlines
Sun 8/242:02 pmSTL - BOS
1 stop19h 21mMultiple Airlines
Deal found 7/29$242
This FlightHub deal was found by Cheapflights users on 7/30. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/159:40 amBOS - STL
1 stop15h 07mFrontier
Sun 8/175:40 pmSTL - BOS
1 stop13h 55mFrontier
Deal found 7/30$245
This CheapOair deal was found by Cheapflights users on 7/30. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/146:30 amBOS - STL
1 stop8h 02mSpirit Airlines
Sun 8/172:30 pmSTL - BOS
1 stop7h 04mSpirit Airlines
Deal found 7/30$246
This American Airlines deal was found by Cheapflights users on 7/30. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/235:28 amBOS - STL
1 stop8h 44mAmerican Airlines
Wed 8/276:55 pmSTL - BOS
Nonstop2h 41mAmerican Airlines
Deal found 7/30$247
This Delta deal was found by Cheapflights users on 7/29. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/288:30 amBOS - STL
1 stop7h 07mDelta
Sat 8/305:25 pmSTL - BOS
1 stop4h 56mDelta
Deal found 7/29$260
This Southwest deal was found by Cheapflights users on 7/31. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/235:35 amBOS - STL
Nonstop2h 55mSouthwest
Tue 8/266:40 pmSTL - BOS
Nonstop2h 35mSouthwest
Deal found 7/31$277
This United Airlines deal was found by Cheapflights users on 7/29. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/146:15 pmBOS - STL
1 stop5h 20mUnited Airlines
Thu 10/1612:25 pmSTL - BOS
1 stop6h 06mUnited Airlines
Deal found 7/29$306

Cheapflights Fare Finder

 
Customize your flight search to find flights from Boston 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 July 31, 2025.
Use the filters below to find and compare flights from Boston to St. Charles that are best for you.

Fly from

Boston

Fly to

St. Charles

Route

Depart

Return

Price

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Fri 8/15

6:30 am-1:32 pm

1 stop8h 02m

Lambert-St Louis

Sun 8/17

5:40 pm-8:35 am

1 stop13h 55m

$242

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Fri 8/15

9:40 am-11:47 pm

1 stop15h 07m

Lambert-St Louis

Sun 8/17

5:40 pm-8:35 am

1 stop13h 55m

$245

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Thu 8/14

6:30 am-1:32 pm

1 stop8h 02m

Lambert-St Louis

Sun 8/17

2:30 pm-10:34 pm

1 stop7h 04m

$246

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Sat 8/23

5:28 am-1:12 pm

1 stop8h 44m

Lambert-St Louis

Wed 8/27

6:55 pm-10:36 pm

Nonstop2h 41m

$247

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Thu 8/28

8:30 am-2:37 pm

1 stop7h 07m

Lambert-St Louis

Sat 8/30

5:25 pm-11:21 pm

1 stop4h 56m

$260

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Sat 8/23

5:35 am-7:30 am

Nonstop2h 55m

Lambert-St Louis

Tue 8/26

6:40 pm-10:15 pm

Nonstop2h 35m

$277

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Tue 10/14

6:15 pm-10:35 pm

1 stop5h 20m

Lambert-St Louis

Thu 10/16

12:25 pm-7:31 pm

1 stop6h 06m

$306

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Thu 8/21

3:37 pm-1:32 pm

2 stops22h 55m

$151

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Tue 10/28

5:15 am-11:45 am

2 stops7h 30m

$154

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Thu 10/9

6:50 am-9:04 am

Nonstop3h 14m

$157

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/30

Showing 1-10 of 14 results
1
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Best time to book a flight from Boston to St. Charles

Have a flexible travel schedule? Discover the best time to fly to St. Charles from Boston 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 Boston to St. Charles

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

Use this chart to determine the optimal time to book a round-trip flight from Boston to St. Charles. Price data was last updated on July 25, 2025.

To ensure you get the cheapest price possible for a flight from Boston to St. Charles, you should look to book at least 63 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 Boston to St. Charles?

Currently, August is the cheapest month in which you can book a flight from Boston to St. Charles (average of $311). Flying from Boston 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 BOS to CH5?

Find hourly flight availability from Boston 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 July 31, 2025.

When flying from Boston to St. Charles, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

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

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

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

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 July 31, 2025.
Peruse reviews from past customers who have flown with Southwest, Delta, and United Airlines from Boston to St. Charles to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,246 reviews

Comfort

8.0

Overall

8.0

Boarding

8.1

Food

7.0

Crew

8.6

Entertainment

7.5

Reviews

1 / 20
8.0
Excellent

Gina,Jul 2025

LAS - DEN

We experienced bad weather, which turned our 1.5 hour flight from Las Vegas to Denver, into 3.5. The pilot and crew kept us updated and explained that we had to circle and or possibly redirect to another airport. After circling for sometime, we were able to land smoothly in Denver. Thank you to all the flight crew, tower control, and all who got us to our destination safely.
Southwest
8.0
Very good
4,246 reviews
Southwest
8.0
Very good
4,246 reviews

Comfort

8.0

Overall

8.0

Boarding

8.1

Food

7.0

Crew

8.6

Entertainment

7.5

Reviews

1 / 20
8.0
Excellent

Gina,Jul 2025

LAS - DEN

We experienced bad weather, which turned our 1.5 hour flight from Las Vegas to Denver, into 3.5. The pilot and crew kept us updated and explained that we had to circle and or possibly redirect to another airport. After circling for sometime, we were able to land smoothly in Denver. Thank you to all the flight crew, tower control, and all who got us to our destination safely.
Delta
8.0
Very good
7,981 reviews
Southwest
8.0
Very good
4,246 reviews

Comfort

8.0

Overall

8.0

Boarding

8.1

Food

7.0

Crew

8.6

Entertainment

7.5

Reviews

1 / 20
8.0
Excellent

Gina,Jul 2025

LAS - DEN

We experienced bad weather, which turned our 1.5 hour flight from Las Vegas to Denver, into 3.5. The pilot and crew kept us updated and explained that we had to circle and or possibly redirect to another airport. After circling for sometime, we were able to land smoothly in Denver. Thank you to all the flight crew, tower control, and all who got us to our destination safely.
United Airlines
7.4
Good
8,900 reviews
Southwest
8.0
Very good
4,246 reviews

Comfort

8.0

Overall

8.0

Boarding

8.1

Food

7.0

Crew

8.6

Entertainment

7.5

Reviews

1 / 20
8.0
Excellent

Gina,Jul 2025

LAS - DEN

We experienced bad weather, which turned our 1.5 hour flight from Las Vegas to Denver, into 3.5. The pilot and crew kept us updated and explained that we had to circle and or possibly redirect to another airport. After circling for sometime, we were able to land smoothly in Denver. Thank you to all the flight crew, tower control, and all who got us to our destination safely.
American Airlines
7.2
Good
10,000 reviews
Southwest
8.0
Very good
4,246 reviews

Comfort

8.0

Overall

8.0

Boarding

8.1

Food

7.0

Crew

8.6

Entertainment

7.5

Reviews

1 / 20
8.0
Excellent

Gina,Jul 2025

LAS - DEN

We experienced bad weather, which turned our 1.5 hour flight from Las Vegas to Denver, into 3.5. The pilot and crew kept us updated and explained that we had to circle and or possibly redirect to another airport. After circling for sometime, we were able to land smoothly in Denver. Thank you to all the flight crew, tower control, and all who got us to our destination safely.
Spirit Airlines
6.3
Okay
8,048 reviews
Southwest
8.0
Very good
4,246 reviews

Comfort

8.0

Overall

8.0

Boarding

8.1

Food

7.0

Crew

8.6

Entertainment

7.5

Reviews

1 / 20
8.0
Excellent

Gina,Jul 2025

LAS - DEN

We experienced bad weather, which turned our 1.5 hour flight from Las Vegas to Denver, into 3.5. The pilot and crew kept us updated and explained that we had to circle and or possibly redirect to another airport. After circling for sometime, we were able to land smoothly in Denver. Thank you to all the flight crew, tower control, and all who got us to our destination safely.

Related info for your journey

Find useful and relevant information for your journey from Boston 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 Boston to St. Charles?

    Boston Logan Intl (BOS) is the airport you will fly out of if you book a flight from Boston to St. Charles. You should not have trouble finding flights to St. Charles from Logan Intl; the airport handles an average of 3 outbound flights to St. Charles per day. You should also have plenty of airline options to choose from since 6 airlines have flights from the Boston airport to St. Charles. It is only a 2.6 mi journey to Logan Intl (BOS) from Boston’s city center.

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

    The Boston Logan Intl to St. Charles flight path was viewed by 43 users in the past month. Keep an eye out for changes in search interest prior to high and low season.

  • What are the cheapest airlines to fly from Boston to St. Charles one-way?

    The cheapest airlines for a one-way flight from Boston to St. Charles are Spirit Airlines ($151), Southwest ($154), and American Airlines ($157).

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

    No one likes to see their flight delayed. When booking a flight from Boston to St. Charles consider choosing Iberia (100%), Republic Airways (100%) or American Airlines (83%) as they are the most reliable in getting you off to your destination on time.

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

    Looking at all options, your cheapest flight can be booked for $127. While the most popular route (Boston Logan Intl - Lambert-St Louis) can be booked for $147 on average our data indicates $303 when flying from Boston to St. Charles.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Boston 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 Boston to St. Charles?

    Currently, August is the cheapest month in which you can book a flight from Boston to St. Charles (average of $311). Flying from Boston 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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Top 6 airlines flying from Boston to St. Charles

Discover the top 6 airlines that operate flights from Boston 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 July 31, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$107Average$186FlexibilityNo cancel feeOn-time65%
FrontierCheapest$113Average$214FlexibilityNo cancel feeOn-time62%
DeltaCheapest$200Average$297FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$257Average$412FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$283Average$503FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$322Average$457FlexibilityNo cancel feeOn-time63%

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