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St. Charles

$57+ 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 1/13. Fares are subject to change and may not be available on all flights or dates of travel.
BOS — STL
Jan 11 — Jan 181
Sun 1/11
Sun 1/18
1 adult, Economy
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Cheapflights Tip: The best prices from Boston Logan Intl to St. Charles are usually found in January or August, booked 47 days in advance, depart on a Wednesday or Thursday and return on a Friday

Cheap 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 December 12, 2025.

This Kiwi.com deal was found by Cheapflights users on 12/11. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/1610:56 amBOS - STL
1 stop12h 37mMultiple Airlines
Tue 1/65:11 pmSTL - BOS
1 stop15h 50mMultiple Airlines
Deal found 12/11$349
This Kiwi.com deal was found by Cheapflights users on 12/11. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/1810:56 amBOS - STL
1 stop12h 37mMultiple Airlines
Sun 12/2110:57 amSTL - BOS
1 stop21h 45mMultiple Airlines
Deal found 12/11$357
This Kiwi.com deal was found by Cheapflights users on 12/11. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/1610:56 amBOS - STL
2 stops24h 18mMultiple Airlines
Sun 12/2110:57 amSTL - BOS
1 stop21h 45mMultiple Airlines
Deal found 12/11$364
This American Airlines deal was found by Cheapflights users on 12/11. 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.
Mon 12/226:36 amBOS - STL
1 stop7h 47mAmerican Airlines
Mon 12/222:50 pmSTL - BOS
Nonstop2h 39mAmerican Airlines
Deal found 12/11$370
This Kiwi.com deal was found by Cheapflights users on 12/11. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/1810:56 amBOS - STL
1 stop12h 37mMultiple Airlines
Thu 12/2510:42 amSTL - BOS
2 stops12h 15mMultiple Airlines
Deal found 12/11$379
This Kiwi.com deal was found by Cheapflights users on 12/10. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/3110:56 amBOS - STL
2 stops23h 44mMultiple Airlines
Sun 1/410:57 amSTL - BOS
1 stop21h 45mMultiple Airlines
Deal found 12/10$386
This Kiwi.com deal was found by Cheapflights users on 12/11. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/148:11 pmBOS - STL
2 stops14h 41mMultiple Airlines
Sun 12/2110:57 amSTL - BOS
1 stop21h 45mMultiple Airlines
Deal found 12/11$390
This Kiwi.com deal was found by Cheapflights users on 12/11. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/1610:56 amBOS - STL
2 stops24h 18mMultiple Airlines
Thu 12/1810:42 amSTL - BOS
1 stop13h 37mMultiple Airlines
Deal found 12/11$401
This American Airlines deal was found by Cheapflights users on 12/11. 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.
Wed 12/317:00 amBOS - STL
Nonstop3h 31mAmerican Airlines
Sat 1/36:02 amSTL - BOS
1 stop6h 01mAmerican Airlines
Deal found 12/11$407
This Kiwi.com deal was found by Cheapflights users on 12/11. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/1710:56 amBOS - STL
2 stops23h 44mMultiple Airlines
Sun 12/2110:57 amSTL - BOS
1 stop21h 45mMultiple Airlines
Deal found 12/11$408
This Kiwi.com deal was found by Cheapflights users on 12/10. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/1211:19 amBOS - STL
2 stops36h 14mMultiple Airlines
Thu 12/184:27 pmSTL - BOS
1 stop16h 34mMultiple Airlines
Deal found 12/10$415

Find 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 December 12, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$334
(Southwest)

One-way from

$57
(Kiwi.com)

Popular in

April

Cheapest in

January

Average price

$450
Provider with most accurate pricing for Boston Logan Intl-Lambert-St Louis flight deals.
Search Deals
Provider most trusted by Cheapflights users for Boston Logan Intl-Lambert-St Louis flights.
Search Deals
From Boston Logan Intl to St. Charles
Search Deals
One-way flight from Boston Logan Intl to St. Charles
Search Deals
Highest demand for flights based on searches. 8% potential increase in price ($41 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($8 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in December 2025
Search Deals

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 December 12, 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

Sat 1/17

5:10 am-1:50 pm

2 stops9h 40m

Lambert-St Louis

Sun 1/18

2:35 pm-10:05 pm

1 stop6h 30m

$349

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Fri 1/16

6:35 am-8:55 am

Nonstop3h 20m

Lambert-St Louis

Sun 1/18

5:55 pm-9:25 pm

Nonstop2h 30m

$369

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Mon 12/22

6:36 am-1:23 pm

1 stop7h 47m

Lambert-St Louis

Mon 12/22

2:50 pm-6:29 pm

Nonstop2h 39m

$370

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Tue 1/27

3:20 pm-9:55 pm

2 stops7h 35m

Lambert-St Louis

Wed 1/28

11:30 am-9:45 pm

2 stops9h 15m

$381

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Tue 1/6

10:30 am-9:13 pm

1 stop11h 43m

Lambert-St Louis

Tue 1/13

9:57 am-6:32 pm

2 stops7h 35m

$394

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Wed 2/18

6:25 am-8:45 am

Nonstop3h 20m

Lambert-St Louis

Sun 2/22

7:50 am-11:20 am

Nonstop2h 30m

$401

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Mon 1/12

7:28 pm-11:59 pm

1 stop5h 31m

Lambert-St Louis

Wed 1/14

9:57 am-5:19 pm

1 stop6h 22m

$403

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Thu 1/1

5:30 am-9:40 am

1 stop5h 10m

Lambert-St Louis

Sun 1/4

8:40 pm-12:10 am

Nonstop2h 30m

$407

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Thu 1/8

6:25 am-8:45 am

Nonstop3h 20m

Lambert-St Louis

Sun 1/11

7:50 am-11:20 am

Nonstop2h 30m

$414

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Wed 1/7

12:29 pm-10:33 pm

1 stop11h 04m

$69

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/11

Showing 1-10 of 20 results
1
2

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 December 5, 2025.

To ensure you get the cheapest price possible for a flight from Boston to St. Charles, you should look to book at least 47 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, December is the cheapest month in which you can book a flight from Boston to St. Charles (average of $107). Flying from Boston to St. Charles in July is currently the most expensive (average of $300). 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 December 12, 2025.

It’s optimal to fly from Boston to St. Charles in the evening. By choosing this option you can save up to 21% on the cost of your flight, compared to a flight in the morning.

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 Saturday 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.

Weekly flight availability from Boston to St. Charles

Explore weekly flight availability from Boston 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 December 12, 2025.

The most flights from BOS to CH5 are scheduled on a Monday (5 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (1 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 December 12, 2025.
Peruse reviews from past customers who have flown with Southwest, Delta, and American 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
7.9
Good
4,253 reviews

Comfort

8.0

Boarding

8.1

Food

7.0

Crew

8.6

Entertainment

7.5

Overall

7.9

Reviews

1 / 20
2.0
Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am
Southwest
7.9
Good
4,253 reviews
Southwest
7.9
Good
4,253 reviews

Comfort

8.0

Boarding

8.1

Food

7.0

Crew

8.6

Entertainment

7.5

Overall

7.9

Reviews

1 / 20
2.0
Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am
Delta
7.9
Good
8,008 reviews
Southwest
7.9
Good
4,253 reviews

Comfort

8.0

Boarding

8.1

Food

7.0

Crew

8.6

Entertainment

7.5

Overall

7.9

Reviews

1 / 20
2.0
Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am
American Airlines
7.2
Good
11,050 reviews
Southwest
7.9
Good
4,253 reviews

Comfort

8.0

Boarding

8.1

Food

7.0

Crew

8.6

Entertainment

7.5

Overall

7.9

Reviews

1 / 20
2.0
Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am
Spirit Airlines
6.3
Okay
8,179 reviews
Southwest
7.9
Good
4,253 reviews

Comfort

8.0

Boarding

8.1

Food

7.0

Crew

8.6

Entertainment

7.5

Overall

7.9

Reviews

1 / 20
2.0
Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am
Frontier
5.8
Fair
3,084 reviews
Southwest
7.9
Good
4,253 reviews

Comfort

8.0

Boarding

8.1

Food

7.0

Crew

8.6

Entertainment

7.5

Overall

7.9

Reviews

1 / 20
2.0
Mediocre

Thomas,Dec 2025

SEA - DEN

Plane two hours late in leaving 1:00 pm west coat time got home next day at 2:45am most car rental places are closed and don’t open till 5am

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 52 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 Boston to St. Charles?

    There are many flights that can get you from Boston to St. Charles in 7h 47m. Fly via Southwest or American Airlines to get the fastest option. There are 1043 mi between Boston and St. Charles. This flight may include one or multiple stops.

  • 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 Frontier ($65), Spirit Airlines ($97), and Delta ($135).

  • 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 (81%) 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 $105. While the most popular route (Boston Logan Intl - Lambert-St Louis) can be booked for $132 on average, our data indicates $356 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, December is the cheapest month in which you can book a flight from Boston to St. Charles (average of $107). Flying from Boston to St. Charles in July is currently the most expensive (average of $300). 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 December 12, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$83Average$147FlexibilityNo cancel feeOn-time65%
FrontierCheapest$90Average$283FlexibilityNo cancel feeOn-time62%
DeltaCheapest$216Average$317FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$292Average$406FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$297Average$506FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$322Average$468FlexibilityNo cancel feeOn-time63%

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