$99+ 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 8/11. Fares are subject to change and may not be available on all flights or dates of travel.
BOS — STL
Jul 15 — Jul 221
Round-trip
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 51 days in advance, depart on a Wednesday or Thursday and return on a Wednesday
Cheap flight deals from Boston to St. Charles
Cheapest
Best
Last-minute
One-way
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 June 15, 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 June 15, 2026.
This Southwest deal was found by Cheapflights users on 6/11. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/85:50 am
BOS
- STL
Nonstop2h 55m
Southwest
Wed 7/83:10 pm
STL
- BOS
1 stop7h 25m
Southwest
Deal found 6/11![Southwest logo]()
$347
This Southwest deal was found by Cheapflights users on 6/12. 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 8/155:30 am
BOS
- STL
Nonstop2h 50m
Southwest
Tue 8/186:30 am
STL
- BOS
1 stop4h 45m
Southwest
Deal found 6/12![Southwest logo]()
$348
This Kiwi.com deal was found by Cheapflights users on 6/13. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/16:00 am
BOS
- STL
2 stops13h 18m
Frontier
Fri 7/35:06 pm
STL
- BOS
1 stop13h 42m
Frontier
Deal found 6/13![Frontier logo]()
$349
This Kiwi.com deal was found by Cheapflights users on 6/12. 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 7/228:41 am
BOS
- STL
2 stops16h 18m
Frontier
Mon 7/274:57 pm
STL
- BOS
1 stop17h 00m
Frontier
Deal found 6/12![Frontier logo]()
$350
This Frontier deal was found by Cheapflights users on 6/11. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/169:10 am
BOS
- STL
1 stop9h 20m
Frontier
Thu 6/186:31 pm
STL
- BOS
1 stop5h 56m
Frontier
Deal found 6/11![Frontier logo]()
$351
This Southwest deal was found by Cheapflights users on 6/12. 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 8/295:30 am
BOS
- STL
Nonstop2h 50m
Southwest
Mon 9/75:45 am
STL
- BOS
1 stop6h 00m
Southwest
Deal found 6/12![Southwest logo]()
$352
This Kiwi.com deal was found by Cheapflights users on 6/10. 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.
Mon 8/2411:05 am
BOS
- STL
1 stop14h 09m
Frontier
Thu 9/36:33 pm
STL
- BOS
2 stops39h 32m
Frontier
Deal found 6/10![Frontier logo]()
$353
This Expedia deal was found by Cheapflights users on 6/10. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 6/116:00 am
BOS
- STL
1 stop12h 30m
Frontier
Tue 6/166:31 pm
STL
- BOS
1 stop5h 56m
Frontier
Deal found 6/10![Frontier logo]()
$354
This Kiwi.com deal was found by Cheapflights users on 6/12. 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 8/1311:59 am
BOS
- STL
2 stops13h 00m
Frontier
Mon 8/174:57 pm
STL
- BOS
1 stop13h 55m
Frontier
Deal found 6/12![Frontier logo]()
$355
This CheapOair deal was found by Cheapflights users on 6/12. 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.
Sun 7/56:00 am
BOS
- STL
1 stop12h 37m
Frontier
Fri 7/104:09 pm
STL
- BOS
1 stop16h 00m
Frontier
Deal found 6/12![Frontier logo]()
$356
This Delta deal was found by Cheapflights users on 6/11. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/86:00 am
BOS
- STL
1 stop6h 47m
Delta
Wed 7/86:58 pm
STL
- BOS
1 stop5h 22m
Delta
Deal found 6/11![Delta logo]()
$357
This Kiwi.com deal was found by Cheapflights users on 6/11. 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 7/810:04 am
BOS
- STL
1 stop14h 55m
Frontier
Fri 7/104:57 pm
STL
- BOS
2 stops18h 04m
Frontier
Deal found 6/11![Frontier logo]()
$358
Best flights from Boston to St. CharlesDiscover carefully curated flight deals from Boston to St. Charles that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated June 15, 2026.
Discover carefully curated flight deals from Boston to St. Charles that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated June 15, 2026.
This Delta deal was found by Cheapflights users on 6/11. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/86:00 am
BOS
- STL
1 stop6h 47m
Delta
Wed 7/86:58 pm
STL
- BOS
1 stop5h 22m
Delta
Deal found 6/11![Delta logo]()
$357
This Southwest deal was found by Cheapflights users on 6/11. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/155:50 am
BOS
- STL
2 stops8h 35m
Southwest
Tue 8/187:15 am
STL
- BOS
2 stops7h 55m
Southwest
Deal found 6/11![Southwest logo]()
$381
This Southwest deal was found by Cheapflights users on 6/12. 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.
Fri 7/35:35 am
BOS
- STL
Nonstop2h 50m
Southwest
Wed 7/83:10 pm
STL
- BOS
1 stop7h 25m
Southwest
Deal found 6/12![Southwest logo]()
$384
This Delta deal was found by Cheapflights users on 6/13. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/135:30 am
BOS
- STL
1 stop5h 07m
Delta
Wed 11/2511:51 am
STL
- BOS
1 stop4h 57m
Delta
Deal found 6/13![Delta logo]()
$415
This Southwest deal was found by Cheapflights users on 6/13. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/66:35 pm
BOS
- STL
Nonstop3h 05m
Southwest
Tue 11/101:20 pm
STL
- BOS
Nonstop2h 25m
Southwest
Deal found 6/13![Southwest logo]()
$389
This Southwest deal was found by Cheapflights users on 6/15. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/201:30 pm
BOS
- STL
2 stops9h 35m
Southwest
Mon 8/242:45 pm
STL
- BOS
2 stops6h 25m
Southwest
Deal found 6/15![Southwest logo]()
$389
This Southwest deal was found by Cheapflights users on 6/11. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 7/195:50 am
BOS
- STL
Nonstop2h 55m
Southwest
Tue 7/217:10 pm
STL
- BOS
Nonstop2h 35m
Southwest
Deal found 6/11![Southwest logo]()
$399
This Southwest deal was found by Cheapflights users on 6/10. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/245:00 am
BOS
- STL
Nonstop2h 50m
Southwest
Thu 9/36:55 pm
STL
- BOS
Nonstop2h 35m
Southwest
Deal found 6/10![Southwest logo]()
$408
This Southwest deal was found by Cheapflights users on 6/14. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/23:50 pm
BOS
- STL
2 stops7h 45m
Southwest
Tue 10/67:45 am
STL
- BOS
1 stop4h 30m
Southwest
Deal found 6/14![Southwest logo]()
$414
This Southwest deal was found by Cheapflights users on 6/13. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/75:50 am
BOS
- STL
Nonstop2h 55m
Southwest
Sun 7/128:00 pm
STL
- BOS
Nonstop2h 35m
Southwest
Deal found 6/13![Southwest logo]()
$417
This Southwest deal was found by Cheapflights users on 6/14. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/96:50 pm
BOS
- STL
Nonstop3h 05m
Southwest
Sat 7/118:45 pm
STL
- BOS
Nonstop2h 35m
Southwest
Deal found 6/14![Southwest logo]()
$427
Last-minute flights from Boston to St. CharlesDiscover last-minute flight deals from Boston to St. Charles. Data last updated June 15, 2026 and is based on user searches.
Discover last-minute flight deals from Boston to St. Charles. Data last updated June 15, 2026 and is based on user searches.
This Frontier deal was found by Cheapflights users on 6/11. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/169:10 am
BOS
- STL
1 stop9h 20m
Frontier
Thu 6/186:31 pm
STL
- BOS
1 stop5h 56m
Frontier
Deal found 6/11![Frontier logo]()
$351
This Kiwi.com deal was found by Cheapflights users on 6/13. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/16:00 am
BOS
- STL
2 stops13h 18m
Frontier
Fri 7/35:06 pm
STL
- BOS
1 stop13h 42m
Frontier
Deal found 6/13![Frontier logo]()
$349
This CheapOair deal was found by Cheapflights users on 6/12. 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.
Sun 7/56:00 am
BOS
- STL
1 stop12h 37m
Frontier
Fri 7/104:09 pm
STL
- BOS
1 stop16h 00m
Frontier
Deal found 6/12![Frontier logo]()
$356
This Kiwi.com deal was found by Cheapflights users on 6/11. 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.
Mon 7/610:04 am
BOS
- STL
2 stops32h 33m
Frontier
Fri 7/104:57 pm
STL
- BOS
1 stop13h 45m
Frontier
Deal found 6/11![Frontier logo]()
$348
This Southwest deal was found by Cheapflights users on 6/11. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/85:50 am
BOS
- STL
Nonstop2h 55m
Southwest
Wed 7/83:10 pm
STL
- BOS
1 stop7h 25m
Southwest
Deal found 6/11![Southwest logo]()
$347
This Delta deal was found by Cheapflights users on 6/11. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/86:00 am
BOS
- STL
1 stop6h 47m
Delta
Wed 7/86:58 pm
STL
- BOS
1 stop5h 22m
Delta
Deal found 6/11![Delta logo]()
$357
This Kiwi.com deal was found by Cheapflights users on 6/11. 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 7/810:04 am
BOS
- STL
1 stop14h 55m
Frontier
Fri 7/104:57 pm
STL
- BOS
2 stops18h 04m
Frontier
Deal found 6/11![Frontier logo]()
$358
This Kiwi.com deal was found by Cheapflights users on 6/11. 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 7/911:52 am
BOS
- STL
1 stop6h 45m
Frontier
Thu 7/167:10 pm
STL
- BOS
2 stops35h 32m
Frontier
Deal found 6/11![Frontier logo]()
$359
This Kiwi.com deal was found by Cheapflights users on 6/14. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/1611:52 am
BOS
- STL
2 stops13h 07m
Frontier
Fri 7/174:57 pm
STL
- BOS
1 stop13h 45m
Frontier
Deal found 6/14![Frontier logo]()
$360
This Kiwi.com deal was found by Cheapflights users on 6/12. 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 7/1611:52 am
BOS
- STL
2 stops13h 07m
Frontier
Mon 7/204:57 pm
STL
- BOS
1 stop17h 00m
Frontier
Deal found 6/12![Frontier logo]()
$361
This Kiwi.com deal was found by Cheapflights users on 6/12. 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 7/228:41 am
BOS
- STL
2 stops16h 18m
Frontier
Mon 7/274:57 pm
STL
- BOS
1 stop17h 00m
Frontier
Deal found 6/12![Frontier logo]()
$350
This Southwest deal was found by Cheapflights users on 6/11. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/225:35 am
BOS
- STL
1 stop5h 00m
Southwest
Tue 7/283:15 pm
STL
- BOS
2 stops7h 10m
Southwest
Deal found 6/11![Southwest logo]()
$362
One-way flights from Boston to St. CharlesSearch for one-way flight options from Boston to St. Charles. Find affordable one-way fares based on user searches. Data last updated June 15, 2026.
Search for one-way flight options from Boston to St. Charles. Find affordable one-way fares based on user searches. Data last updated June 15, 2026.
This Kiwi.com deal was found by Cheapflights users on 6/11. 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 8/1111:59 am
BOS
- STL
1 stop6h 38m
Frontier
Deal found 6/11![Frontier logo]()
$99
This Kiwi.com deal was found by Cheapflights users on 6/12. 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 8/189:12 am
BOS
- STL
1 stop9h 18m
Frontier
Deal found 6/12![Frontier logo]()
$106
This Kiwi.com deal was found by Cheapflights users on 6/10. 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.
Tue 9/89:12 am
BOS
- STL
1 stop25h 28m
Frontier
Deal found 6/10![Frontier logo]()
$107
This Frontier deal was found by Cheapflights users on 6/14. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/810:04 am
BOS
- STL
1 stop14h 55m
Frontier
Deal found 6/14![Frontier logo]()
$122
This Trip.com deal was found by Cheapflights users on 6/14. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/1510:04 am
BOS
- STL
1 stop14h 55m
Frontier
Deal found 6/14![Frontier logo]()
$124
This Kiwi.com deal was found by Cheapflights users on 6/12. 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 7/1112:56 pm
BOS
- STL
1 stop29h 41m
Frontier
Deal found 6/12![Frontier logo]()
$127
This Kiwi.com deal was found by Cheapflights users on 6/13. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/91:00 pm
BOS
- STL
1 stop21h 40m
Frontier
Deal found 6/13![Frontier logo]()
$128
This Frontier deal was found by Cheapflights users on 6/14. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/1311:59 am
BOS
- STL
1 stop6h 38m
Frontier
Deal found 6/14![Frontier logo]()
$129
This Frontier deal was found by Cheapflights users on 6/15. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/911:52 am
BOS
- STL
1 stop6h 45m
Frontier
Deal found 6/15![Frontier logo]()
$134
This Frontier deal was found by Cheapflights users on 6/15. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/1811:05 am
BOS
- STL
1 stop9h 34m
Frontier
Deal found 6/15![Frontier logo]()
$135
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 June 15, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $347 (Southwest) |
One-way from | $99 (Kiwi.com) |
Popular in | July |
Cheapest in | August |
Average price | $537 |
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 June 15, 2026.
Use the filters below to find and compare flights from Boston to St. Charles that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
BostonSt. Louis
BOS - STL
BOSSTL
Boston Logan Intl
Wed 7/8
6:00 am-11:47 am
1 stop6h 47m
Lambert-St Louis
Wed 7/8
6:58 pm-1:20 am
1 stop5h 22m
$357
BostonSt. Louis
BOS - STL
BOSSTL
Boston Logan Intl
Sat 8/15
5:50 am-1:25 pm
2 stops8h 35m
Lambert-St Louis
Tue 8/18
7:15 am-4:10 pm
2 stops7h 55m
$381
BostonSt. Louis
BOS - STL
BOSSTL
Boston Logan Intl
Fri 7/3
5:35 am-7:25 am
Nonstop2h 50m
Lambert-St Louis
Wed 7/8
3:10 pm-11:35 pm
1 stop7h 25m
$384
BostonSt. Louis
BOS - STL
BOSSTL
Boston Logan Intl
Fri 11/6
6:35 pm-8:40 pm
Nonstop3h 05m
Lambert-St Louis
Tue 11/10
1:20 pm-4:45 pm
Nonstop2h 25m
$389
BostonSt. Louis
BOS - STL
BOSSTL
Boston Logan Intl
Thu 8/20
1:30 pm-10:05 pm
2 stops9h 35m
Lambert-St Louis
Mon 8/24
2:45 pm-10:10 pm
2 stops6h 25m
$389
BostonSt. Louis
BOS - STL
BOSSTL
Boston Logan Intl
Sun 7/19
5:50 am-7:45 am
Nonstop2h 55m
Lambert-St Louis
Tue 7/21
7:10 pm-10:45 pm
Nonstop2h 35m
$399
Quickest round-trip
BostonSt. Louis
BOS - STL
BOSSTL
Boston Logan Intl
Mon 8/24
5:00 am-6:50 am
Nonstop2h 50m
Lambert-St Louis
Thu 9/3
6:55 pm-10:30 pm
Nonstop2h 35m
$408
BostonSt. Louis
BOS - STL
BOSSTL
Boston Logan Intl
Fri 10/2
3:50 pm-10:35 pm
2 stops7h 45m
Lambert-St Louis
Tue 10/6
7:45 am-1:15 pm
1 stop4h 30m
$414
BostonSt. Louis
BOS - STL
BOSSTL
Boston Logan Intl
Thu 8/13
5:30 am-9:37 am
1 stop5h 07m
Lambert-St Louis
Wed 11/25
11:51 am-5:48 pm
1 stop4h 57m
$415
BostonSt. Louis
BOS - STL
BOSSTL
Boston Logan Intl
Tue 7/7
5:50 am-7:45 am
Nonstop2h 55m
Lambert-St Louis
Sun 7/12
8:00 pm-11:35 pm
Nonstop2h 35m
$417
Showing 1-10 of 22 resultsSorted by cheapest first
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.
BOS-STL
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
BOS-CH5
BOS-STL
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 June 15, 2026.
It’s optimal to fly from Boston to St. Charles in the evening. By choosing this option you can save up to 10% on the cost of your flight, compared to a flight at noon.
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 June 15, 2026.
The most flights from BOS to CH5 are scheduled on a Monday (8 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (2 on average).
How much does it cost to fly round-trip from Boston to St. Charles?
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 June 8, 2026.
Travelers seeking maximum savings on their Boston to St. Charles flight should consider departing on Thursday evenings when fares are most often at their lowest. Sunday 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 June 15, 2026.
Peruse reviews from past customers who have flown with Southwest,Delta, andAmerican 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
Overall
7.9
Entertainment
7.5
Boarding
8.1
Comfort
8.0
Crew
8.6
Reviews
1 / 20
8.0
ExcellentLa Tracimeldamarcos,Jun 2026
LAX - SLC
Food
7.0
Overall
7.9
Entertainment
7.5
Boarding
8.1
Comfort
8.0
Crew
8.6
Reviews
1 / 20
8.0
ExcellentLa Tracimeldamarcos,Jun 2026
LAX - SLC
Food
7.0
Overall
7.9
Entertainment
7.5
Boarding
8.1
Comfort
8.0
Crew
8.6
Reviews
1 / 20
8.0
ExcellentLa Tracimeldamarcos,Jun 2026
LAX - SLC
Food
7.0
Overall
7.9
Entertainment
7.5
Boarding
8.1
Comfort
8.0
Crew
8.6
Reviews
1 / 20
8.0
ExcellentLa Tracimeldamarcos,Jun 2026
LAX - SLC
Food
7.0
Overall
7.9
Entertainment
7.5
Boarding
8.1
Comfort
8.0
Crew
8.6
Reviews
1 / 20
8.0
ExcellentLa Tracimeldamarcos,Jun 2026
LAX - SLC
Food
7.0
Overall
7.9
Entertainment
7.5
Boarding
8.1
Comfort
8.0
Crew
8.6
Reviews
1 / 20
8.0
ExcellentLa Tracimeldamarcos,Jun 2026
LAX - SLC
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
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Complete your trip
Complete your trip to St. Charles by adding a car rental and/or hotel reservation to your travel itinerary.
Search flights from Boston to St. Charles by cabin class
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Boston and St. Charles flights
Browse other Boston and St. Charles flight options. Last updated on June 15, 2026.
Other flights from Boston
Browse through other flights departing from Boston. Flights are based on user searches made on Cheapflights and were last updated on June 15, 2026.
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Boston to St. Charles flights
Consider these flights traveling from Boston to St. Charles.
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 June 15, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$90 | Average$250 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$148 | Average$516 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$286 | Average$538 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$297 | Average$408 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$314 | Average$487 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$327 | Average$430 | FlexibilityNo cancel fee | On-time62% |