$68 Find Cheap Flights from Boston to St. Charles

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Boston to St. Charles departing on 1/10. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
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1 adult, Economy, 0 bags

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Flight Deals

Cheap Flights from Boston to St. Charles (BOS-STL)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Boston to St. Charles that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Boston to St. Charles

Sat, Jan 17 - Mon, Jan 19
American Airlines Logo
6:30 am - 9:03 amBOS-STL
3h 33mnonstop
American Airlines Logo
2:54 pm - 6:31 pmSTL-BOS
2h 37mnonstop
$328American Airlines
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Mon, Nov 24 - Tue, Nov 25
American Airlines Logo
6:00 am - 11:03 amBOS-STL
6h 03m1 stop
American Airlines Logo
2:52 pm - 6:30 pmSTL-BOS
2h 38mnonstop
$329American Airlines
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Sun, Nov 23 - Tue, Nov 25
Frontier Logo
6:00 am - 2:29 pmBOS-STL
9h 29m1 stop
Frontier Logo
3:14 pm - 12:44 amSTL-BOS
8h 30m1 stop
$330Frontier
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Thu, Nov 13 - Thu, Nov 20
Spirit Airlines Logo
6:16 am - 5:57 pmBOS-STL
12h 41m1 stop
Spirit Airlines Logo
10:53 am - 4:50 pmSTL-BOS
28h 57m3 stops
$334Spirit Airlines
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Mon, Nov 10 - Thu, Nov 13
Frontier Logo
9:55 am - 9:07 amBOS-STL
24h 12m2 stops
Frontier Logo
2:12 pm - 8:28 amSTL-BOS
17h 16m1 stop
$337Frontier
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Wed, Dec 31 - Mon, Jan 5
Delta Logo
6:15 pm - 11:38 pmBOS-STL
6h 23m1 stop
Delta Logo
6:25 am - 1:22 pmSTL-BOS
5h 57m1 stop
$348Delta
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Thu, Dec 4 - Mon, Dec 8
Southwest Logo
5:15 pm - 7:30 pmBOS-STL
3h 15mnonstop
Southwest Logo
6:10 pm - 9:40 pmSTL-BOS
2h 30mnonstop
$349Southwest
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Sat, Jan 10 - Wed, Jan 14
Southwest Logo
7:10 am - 9:30 amBOS-STL
3h 20mnonstop
Southwest Logo
5:55 pm - 9:25 pmSTL-BOS
2h 30mnonstop
$350Southwest
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Thu, Jan 1 - Mon, Jan 5
Delta Logo
6:15 pm - 11:38 pmBOS-STL
6h 23m1 stop
Delta Logo
9:45 am - 3:22 pmSTL-BOS
4h 37m1 stop
$373Delta
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Fri, Nov 21 - Thu, Dec 4
Spirit Airlines Logo
1:30 pm - 8:57 amBOS-STL
20h 27m2 stops
Spirit Airlines Logo
2:47 pm - 7:06 pmSTL-BOS
27h 19m3 stops
$380Spirit Airlines
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Everything you should know

Cheapest round-trip
$328
Overall average: $401
American Airlines
Sat 1/17Mon 1/19
BOS - STL • Non-stop
Cheapest one-way
$68
Typical prices: $217-$495
Frontier
Sat 1/10
BOS - STL • 1 stop
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We hope you love your trip to St. Charles!
Useful Info

Good to know

Low seasonJanuary
Cheapest flight$68
Best time to beat the crowds with an average 10% drop in price.
Most popular time to fly with an average 14% increase in price.
Flight from Boston to St. Louis

When to book flights from Boston to St. Charles

Are your dates flexible? Find out the best times to travel from Boston to St. Charles based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price

FAQs for booking flights from Boston to St. Charles

  • Which airports will I be using when flying from Boston to St. Charles?

    When flying out of Boston you’ll be using Boston Logan Intl. St. Charles does not have its own airport so you’ll be flying into nearby Lambert-St Louis airport, which is 7.2 mi away.

  • How long does a flight from Boston to St. Charles take?

    Direct flights cover the 1,043 miles separating Boston and St. Charles in about 3h 05m.

  • How many flights are there between Boston and St. Charles?

    8 direct flights run between Boston and St. Charles on a daily basis. On average, there are about 57 departures each week.

  • What’s the cheapest day of the week to fly between Boston and St. Charles?

    Consider leaving on a Saturday and avoid Fridays if you are looking for the best rates. For your return to Boston, you’ll find the best rates on Fridays and the most expensive ones on Wednesdays.

  • How does KAYAK find such low prices on flights from Boston to St. Charles?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Boston to St. Charles.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Boston to St. Charles?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to St. Charles from Boston is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Boston to St. Charles?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to St. Charles with an airline and back to Boston with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Boston to St. Charles?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to St. Charles from Boston up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • Which airlines provide the cheapest flights from Boston to St. Charles?

    In the last 72 hours, the cheapest one-way ticket between Boston and St. Charles found on KAYAK was with Frontier for $68. American Airlines offered a round-trip connection from $328 and Frontier from $330.

Top tips for finding cheap flights from Boston to St. Charles

  • There is no airport in St. Charles. Instead, you’ll be flying into St. Louis Lambert Airport when flying between Boston and St. Charles.
  • The cheapest flight from Boston to St. Charles was found 25 days before departure, on average.
  • Book at least 2 weeks before departure in order to get a below-average price.
  • High season is considered to be September, October and November. The cheapest month to fly is August.

Reviews of the top 5 airlines serving Boston to St. Charles

 
Need help choosing which airline to fly with from Boston to St. Charles? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
SouthwestOverall score based on 4241 reviews
8.0Comfort
7.5Entertainment
8.6Crew
8.1Boarding
7.0Food
Airline reviews

Ever since Southwest starting charging for bags, passengers don't want to pay to check their bags, so the gate agents have to beg people to check their roller bags now because there's "not enough space". This was a terrible business move by Southwest.

8.0 ExcellentGreg, Oct 2025OAK - BUR
Read more Southwest reviews

Ever since Southwest starting charging for bags, passengers don't want to pay to check their bags, so the gate agents have to beg people to check their roller bags now because there's "not enough space". This was a terrible business move by Southwest.

Full cans of soda would be nice. A choice between two snacks would be appreciated.

Tried watching free movie and it kept freezing so I couldn’t finish.

All was good. I just had a hard time getting connected to the WiFi/internet during the flight

Sacrament staff are always polite and helpful. Airport is easy to maneuver and boarding is straightforward.

Great flight. Outstanding Service. Southwest was able to put us on a direct flight to Denver when the connection could have been affected by a later arrival to Baltimore. The direct flight was less expensive that the flight with the connection in Baltimore.

Delays delays delays. Late taking off, late landing, wait for a gate, etc.

Boarded on time but once we were ready for take off, the crew determined that, although every seat was taken, somehow someone was on the wrong flight. Delay, delay delay, announcements and ended up with one person checking EVERY ID against their passenger Manifest only to figure out it was a "clerical error." We departed 54 minutes late causing me to run in the St. Louis Airport to make my connection and lose the priority boarding spot I had paid for. Unnecessary delay.

I was re-booked onto another flight because my original flight was delayed and I would have missed my connector. I ended up in the “C” group after paying extra to be in the “A “ group on the original flight. At least if you’re going to re-book people, re-book them into the same group.

Flight was delayed due to plane not passing inspection And one of the crew had to time out and we had to wait for another one A 3 hour delay

Staff were friendly and happy. Delta could make sure passengers that don't have the app know of changes. Without Kayak I would not have known about the change of gate or the delay. Kayak was faster to notify me.

They ended up paying for the bag twice, but the counter wouldn't take my baggage receipt. Left it to me to resolve. Not sure how to resolve the issue.

The customer service before board was very rude and when I expressed my concerns about making the connecting flight she laughed and told me I bought the wrong ticket. I explained once it showed the flight was delayed it no longer let me change seats or anything. I was trying to upgrade to make sure I would get to the next gate on time.

Non stop on long haul is the way to go. Great experience

The flight used a B767 with a very old interior from before 2014. The entertainment system did not work at all during the flight despite attempts to reset the system. It was like they flew this route just to be competitive.

They changed planes and the new plane couldn’t carry enough fuel to fly across the country so we had to stop in Kansas City to refuel. Flight was delayed .

Flight was too crowded and seats are too small, especially since passengrs are getting larger. Having a middle seat is ALWAYS tough! Woman on my left was large & kept creeping in to my space. Flight personnel were great! Have more savory rather than sweet snacks please.

Flight was crowded and the woman sitting on my left was large & kept crouching in to my space. You need bigger seats or smaller passengers to fit into the seats you DO have! Snack were OK. Would appreciate if airlines had more savory rather than sweet snacks, thank you!

Delayed flight (1hour) plus a long layover after an overnight flight with no backup plane available.

We were delayed, which I think had to do with air traffic control. Otherwise, everything was great.

The flight attendant, a black woman with curly hair who sat near Row 21, was wonderful and kind.

It was good..clean, comfy seat. Friendly warm welcoming crew. Was able to check my cabin luggage at the gate which I was able to pickup in a decent time from baggage claim. The app gave all updates from delays to baggage claim info. Overall smooth flight.

Flight was delayed leaving Dallas. Arrived about 2 hours later than scheduled.

Flight delayed and missed connection. Rescheduled flight cancelled after 6 hrs wait. Rerouted thru ORD, flight cancelled, overnight stay in ORD. Still in the air on new flight!

We are too tired and frustrated to comment politely at this point

Terrible. Our luggage was delayed and couldn’t be delivered for several days. We got bad information from the airline agents at baggage claim. We had to pick up our car so we wouldn’t be charged for an extra day. We got lost in the maze of airport parking. The baggage claim agents didn’t offer us any compensation for our extra time and expense. We are tired, hungry and very frustrated.

The flight was flawless and we even arrived between 20 and 25 minutes early!

The only thing to like was that we eventually got to our destination

Delayed delayed delayed and no offer for food or vouchers

Typically flights with AA are good. The staff are pleasant, welcoming, and efficient.

the plane was not full so the flight attendant had me move to an empty row which made for a good flight. The software for logging on and booking and confirming the flight is much too cumbersome.

Always comes in handy when I want a quick weekend getaway.

For the price I could have taken a “name brand” airline. No drink no snack and constant emails trying to get addition money for EVERYTHING other airlines include in the price. It looks cheaper but it’s Judy bait and switch and emails non stop!

The gate agents for spirit at EWR wouldn’t give me my ticket to board when I arrived 50 min from the flight, saying that I wouldn’t make my flight. They tried to reschedule me to arrive at my destination 14 hours after the original flight, which included a 10 hr layover in another city. I rebooked with another airline and it took me a total of 5 min to go through security. Then I see a charge on my card for a $100 change fee that I did not approve. Beware of this horrible place and these horrible people

Excessive fees for flight delays. What a Scam. I was not able to attend the wedding I needed to go.

Waited at the airport for over 4 hours to board this flight. Terrible airline

Was supposed to take off 8:00 last night. Got delayed till 8:00 this morning

It was terrible, we had to board and unboard the flight with a hour delay that caused me to miss an appointment and a surprise for my wife

When the flight ticket is expensive and you have to purchase check in luggage and there is no snacks, no entertainment, tight seats stuffed in the back of the plane not such good experience. I would like some to reach out to me . I paid for check luggage when I bought the ticket they made me pay again on the return flight extra $70. Very frustrating.

Excellent experience when I am looking for a budget airline where the main expectation is getting me from point A to point B with no frills.

Terrible. The canceled my entire flight when I requested a refund for a trip frontier canceled trip one way.

Boarding was on time and plane departed as scheduled. There are obviously no amenities (food, drink, entertainment) on Frontier, but there also didn't seem to be any issues with luggage space either.

Inbound plane was on time and flight departed on time with no issues while boarding.

I knew going into this that Frontier, being a low cost carrier, would be pretty bare bones and charge for most extras but this was made up for by the fact that the airplane was a reasonably new Airbus, every employee was great and best of all, Everett Washington is an amazing airport - thanks Frontier for flying there!!!

i was unable to check in the flight. refund requested

It was well done. It was my first time flying with them and I was nervous b/c I have heard of many cancelled and/or delray flights. Everything went smoothly.

Just know that everything, and I mean everything is “ala cart”. 60$ just to put something in the overhead bin. I will never fly Frontier again nor do I recommend them to anyone else.

The single worst check in experience I could imagine. I’ll never do any business with Frontier or any affiliated company

Too many extra fees, uncomfortable, little leg room. Will not recommend this airline.

Everyone seemed to be in zone 1 for boarding. Maybe break it up a little. Otherwise, smooth flight.

Everything you need to know for your flight from Boston to St. Charles

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