$61+ 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 3/1. Fares are subject to change and may not be available on all flights or dates of travel.
BOS — STL
Feb 27 — Mar 61
1 adult, Economy
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Find cheap flights from Boston to St. Charles with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheapflights Tip: The best prices from Boston Logan Intl to St. Charles are usually found in August or September, booked 47 days in advance, depart on a Wednesday or Thursday and return on a Wednesday
Cheap flight deals from Boston to St. Charles
Cheapest flights from Boston to St. CharlesExplore 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 January 28, 2026.
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 January 28, 2026.
This American Airlines deal was found by Cheapflights users on 1/27. 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 2/2110:48 am
BOS
- STL
1 stop11h 24m
American Airlines
Wed 2/255:50 pm
STL
- BOS
Nonstop2h 40m
American Airlines
Deal found 1/27![American Airlines logo]()
$316
This Kiwi.com deal was found by Cheapflights users on 1/25. 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.
Sat 3/712:36 pm
BOS
- STL
2 stops18h 21m
Multiple Airlines
Tue 3/104:51 pm
STL
- BOS
1 stop17h 57m
Multiple Airlines
Deal found 1/25![Multiple Airlines logo]()
$318
This Kiwi.com deal was found by Cheapflights users on 1/25. 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 3/64:22 pm
BOS
- STL
1 stop7h 57m
Multiple Airlines
Sat 3/78:12 pm
STL
- BOS
2 stops13h 29m
Multiple Airlines
Deal found 1/25![Multiple Airlines logo]()
$320
This Kiwi.com deal was found by Cheapflights users on 1/26. 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 2/206:00 am
BOS
- STL
1 stop25h 51m
Frontier
Sun 2/223:49 pm
STL
- BOS
2 stops32h 24m
Frontier
Deal found 1/26![Frontier logo]()
$322
This Kiwi.com deal was found by Cheapflights users on 1/27. 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.
Mon 4/64:23 pm
BOS
- STL
1 stop8h 02m
Multiple Airlines
Tue 4/74:54 pm
STL
- BOS
2 stops21h 34m
Multiple Airlines
Deal found 1/27![Multiple Airlines logo]()
$324
This Kiwi.com deal was found by Cheapflights users on 1/25. 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 3/64:22 pm
BOS
- STL
1 stop7h 57m
Multiple Airlines
Sun 3/87:52 am
STL
- BOS
2 stops26h 49m
Multiple Airlines
Deal found 1/25![Multiple Airlines logo]()
$325
This Kiwi.com deal was found by Cheapflights users on 1/25. 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.
Sat 3/74:51 pm
BOS
- STL
1 stop14h 06m
Multiple Airlines
Wed 3/1111:32 am
STL
- BOS
2 stops25h 23m
Multiple Airlines
Deal found 1/25![Multiple Airlines logo]()
$326
This Kiwi.com deal was found by Cheapflights users on 1/27. 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 2/1812:42 pm
BOS
- STL
1 stop10h 45m
Multiple Airlines
Fri 2/208:20 pm
STL
- BOS
1 stop27h 09m
Multiple Airlines
Deal found 1/27![Multiple Airlines logo]()
$328
This Kiwi.com deal was found by Cheapflights users on 1/27. 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 4/54:23 pm
BOS
- STL
1 stop16h 28m
Multiple Airlines
Tue 4/711:21 am
STL
- BOS
2 stops11h 38m
Multiple Airlines
Deal found 1/27![Multiple Airlines logo]()
$330
This American Airlines deal was found by Cheapflights users on 1/27. 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.
Thu 3/199:05 am
BOS
- STL
Nonstop3h 24m
American Airlines
Tue 3/319:59 am
STL
- BOS
1 stop8h 24m
American Airlines
Deal found 1/27![American Airlines logo]()
$331
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 January 28, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $316 (American Airlines) |
One-way from | $61 (Trip.com) |
Popular in | April |
Cheapest in | August |
Average price | $441 |
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 January 28, 2026.
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
Thu 5/14
3:00 pm-5:12 pm
Nonstop3h 12m
Lambert-St Louis
Sat 5/16
6:00 am-3:19 pm
1 stop8h 19m
$348
BostonSt. Louis
BOS - STL
BOSSTL
Boston Logan Intl
Sun 3/15
9:35 am-7:02 am
1 stop22h 27m
Lambert-St Louis
Thu 3/19
8:02 am-9:33 pm
1 stop12h 31m
$367
BostonSt. Louis
BOS - STL
BOSSTL
Boston Logan Intl
Wed 3/25
5:25 pm-7:35 pm
Nonstop3h 10m
Lambert-St Louis
Mon 3/30
7:45 pm-11:10 pm
Nonstop2h 25m
$371
BostonSt. Louis
BOS - STL
BOSSTL
Boston Logan Intl
Mon 2/23
4:10 pm-10:40 pm
1 stop7h 30m
Lambert-St Louis
Wed 2/25
5:55 pm-9:25 pm
Nonstop2h 30m
$371
BostonSt. Louis
BOS - STL
BOSSTL
Boston Logan Intl
Thu 3/26
5:15 am-7:25 am
Nonstop3h 10m
Lambert-St Louis
Mon 3/30
7:45 pm-11:10 pm
Nonstop2h 25m
$371
BostonSt. Louis
BOS - STL
BOSSTL
Boston Logan Intl
Wed 5/13
5:45 am-7:45 am
Nonstop3h 00m
Lambert-St Louis
Sat 5/16
6:55 pm-10:25 pm
Nonstop2h 30m
$371
BostonSt. Louis
BOS - STL
BOSSTL
Boston Logan Intl
Wed 5/6
2:25 pm-10:00 pm
2 stops8h 35m
Lambert-St Louis
Sat 5/9
10:55 am-6:45 pm
2 stops6h 50m
$384
BostonSt. Louis
BOS - STL
BOSSTL
Boston Logan Intl
Sat 2/28
5:35 am-4:02 pm
2 stops11h 27m
Lambert-St Louis
Mon 3/2
6:55 pm-12:46 pm
1 stop16h 51m
$387
BostonSt. Louis
BOS - STL
BOSSTL
Boston Logan Intl
Tue 3/24
5:30 am-7:35 am
Nonstop3h 05m
Lambert-St Louis
Sun 3/29
7:40 pm-11:05 pm
Nonstop2h 25m
$389
BostonSt. Louis
BOS - STL
BOSSTL
Boston Logan Intl
Wed 3/11
12:07 pm-5:00 pm
1 stop5h 53m
Lambert-St Louis
Sun 3/15
6:25 am-12:49 pm
1 stop5h 24m
$393
Showing 1-10 of 22 results
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 January 23, 2026.
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, August is the cheapest month in which you can book a flight from Boston to St. Charles (average of $179). 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 January 28, 2026.
It’s optimal to fly from Boston to St. Charles in the evening. By choosing this option you can save up to 6% on the cost of your flight, compared to a flight at noon.
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 January 24, 2026.
Travelers seeking maximum savings on their Boston to St. Charles flight should consider departing on Monday evenings when fares are most often at their lowest. Tuesday at noon 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 January 28, 2026.
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.
Food
7.0
Boarding
8.1
Crew
8.6
Entertainment
7.5
Comfort
8.0
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Food
7.0
Boarding
8.1
Crew
8.6
Entertainment
7.5
Comfort
8.0
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Food
7.0
Boarding
8.1
Crew
8.6
Entertainment
7.5
Comfort
8.0
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Food
7.0
Boarding
8.1
Crew
8.6
Entertainment
7.5
Comfort
8.0
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Food
7.0
Boarding
8.1
Crew
8.6
Entertainment
7.5
Comfort
8.0
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Food
7.0
Boarding
8.1
Crew
8.6
Entertainment
7.5
Comfort
8.0
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
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.
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Alternative routes for Boston to St. Charles
See prices for flight routes from nearby airports that may be better suited for you.
Top 7 airlines flying from Boston to St. Charles
Discover the top 7 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 January 28, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$63 | Average$207 | FlexibilityNo cancel fee | On-time65% | |
| Cheapest$90 | Average$270 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$154 | Average$324 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$288 | Average$503 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$292 | Average$424 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$318 | Average$470 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$385 | Average$430 | FlexibilityNo cancel fee | On-time62% |