$72 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 9/11. 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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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

Fri, Aug 22 - Mon, Aug 25
Spirit Airlines Logo
6:30 am - 1:32 pmBOS-STL
8h 02m1 stop
Spirit Airlines Logo
2:30 pm - 10:34 pmSTL-BOS
7h 04m1 stop
$131Spirit Airlines
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Thu, Aug 14 - Mon, Aug 18
Spirit Airlines Logo
6:30 am - 1:32 pmBOS-STL
8h 02m1 stop
Spirit Airlines Logo
2:30 pm - 10:34 pmSTL-BOS
7h 04m1 stop
$132Spirit Airlines
Find Deal
Thu, Aug 28 - Sun, Aug 31
Spirit Airlines Logo
6:30 am - 1:32 pmBOS-STL
8h 02m1 stop
Spirit Airlines Logo
2:30 pm - 10:34 pmSTL-BOS
7h 04m1 stop
$150Spirit Airlines
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Tue, Sep 30 - Tue, Oct 7
Southwest Logo
7:35 am - 9:30 amBOS-STL
2h 55mnonstop
Southwest Logo
4:15 pm - 10:35 pmSTL-BOS
5h 20m1 stop
$153Southwest
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Tue, Sep 30 - Tue, Oct 7
Southwest Logo
5:20 am - 9:35 amBOS-STL
5h 15m1 stop
Southwest Logo
4:15 pm - 10:35 pmSTL-BOS
5h 20m1 stop
$162Southwest
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Sat, Aug 30 - Wed, Sep 3
American Airlines Logo
1:00 pm - 8:50 pmBOS-STL
8h 50m1 stop
American Airlines Logo
9:46 am - 1:26 pmSTL-BOS
2h 40mnonstop
$181American Airlines
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Thu, Aug 21 - Sun, Aug 24
American Airlines Logo
4:10 pm - 6:19 pmBOS-STL
3h 09mnonstop
American Airlines Logo
7:23 am - 4:50 pmSTL-BOS
8h 27m1 stop
$188American Airlines
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Sun, Sep 14 - Tue, Sep 16
United Airlines Logo
6:56 pm - 11:44 pmBOS-STL
5h 48m1 stop
United Airlines Logo
7:08 am - 1:24 pmSTL-BOS
5h 16m1 stop
$214United Airlines
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Wed, Aug 13 - Fri, Aug 15
Delta Logo
5:25 pm - 10:02 pmBOS-STL
5h 37m1 stop
Delta Logo
6:49 pm - 1:20 amSTL-BOS
5h 31m1 stop
$217Delta
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Thu, Aug 14 - Thu, Aug 14
Delta Logo
5:15 am - 9:32 amBOS-STL
5h 17m1 stop
Delta Logo
6:49 pm - 1:20 amSTL-BOS
5h 31m1 stop
$231Delta
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Useful Info

Good to know

Low seasonJanuary
High seasonApril
Cheapest flight$72
Best time to beat the crowds with an average 8% drop in price.
Most popular time to fly with an average 17% 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 2h 55m.

  • 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 56 departures each week.

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

    Consider leaving on a Friday and avoid Wednesdays if you are looking for the best rates. For your return to Boston, you’ll find the best rates on Thursdays 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 Southwest for $72. Spirit Airlines offered a round-trip connection from $131 and Southwest from $153.

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 63 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 March, April and May. The cheapest month to fly is September.

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 4246 reviews
8.6Crew
7.6Entertainment
8.1Boarding
8.0Comfort
7.0Food
Airline reviews

The Southwest employees (all two of them) were very nice and cheerful despite the fact the line to self-check a bag (simply drop it off) was hundreds of people long. Thank God I arrived early to the airport because I stood in this line for at least an hour. Once on the flight that had been delayed by an hour, we had no Wi-Fi and thus no entertainment. Finally, I hope the investor strong arm tactics against Southwest pay off in a short-term windfall to your C-Suite because the rest of you are screwed. I have been a faithful Southwest customer for 15 years due to everything you just got rid of. I'm flying to Idaho and Washington in October, both places I used to simply book with Southwest without a second thought now with Frontier (Washington) and United (Idaho) because they offer everything the "new" Southwest does but cheaper and at better times, destinations, etc. This really makes me sad...

4.0 OkayGreg, Jul 2025PDX - DEN
Read more Southwest reviews

The Southwest employees (all two of them) were very nice and cheerful despite the fact the line to self-check a bag (simply drop it off) was hundreds of people long. Thank God I arrived early to the airport because I stood in this line for at least an hour. Once on the flight that had been delayed by an hour, we had no Wi-Fi and thus no entertainment. Finally, I hope the investor strong arm tactics against Southwest pay off in a short-term windfall to your C-Suite because the rest of you are screwed. I have been a faithful Southwest customer for 15 years due to everything you just got rid of. I'm flying to Idaho and Washington in October, both places I used to simply book with Southwest without a second thought now with Frontier (Washington) and United (Idaho) because they offer everything the "new" Southwest does but cheaper and at better times, destinations, etc. This really makes me sad...

It was okay. The plane was delayed from earlier in the day, but they kept updating the departure time, sometimes later, sometimes earlier. That was stressful. Once we finally got on and took off, it was fine. I was supposed to have a connection in Chicago to Los Angeles, and the time for so late I was rebooked to arrive in LA 3 hours late. The departure time to Chicago later became early enough to have taken my original connection and arrive earlier but that wasn't an option.

It was one and half hour late... Not sure if any other experience matters.

Delayed flight. Nicest crew member was a SW pilot flying seated next to me who kindly move to seat the final passenger. Flight extra delayed. My cup of refreshment of ginger ale was so packed with ice it was literally 2 sips.

For my birthday trip this was my second time ever flying, this trip was the best.

after landing, we stay 2 hours on the taxi way before reaching the gate The airline and the crew were good though

No trays in our seats, we sat in first row, purchased a business class fare. Had to hold our drinks and snack in our hands. No plugs for our cell phones. Had to pay for it a drink cocktail each. Seats so uncomfortable.

Flight wasn’t even full, but too many carry-ons caused us to run out of bin space. New bag fee has folks who would usually check their bags carrying on. Watching Southwest morph into Spirit/Frontier is so sad to watch

Sat on tarmac for 2 hours and then missed my connecting flight

First time traveling on Southwest since bag fees were implemented. Usual good service. Just more expensive now.

Very late arrival at PWM. Late jet getting to ATL. Equipment problem with aircraft - could not get enough water onto plane., Another delay getting FAA approval for flight with bottled H2O. Not the crew’s problem.

Everything was fine except the entertainment was not working for half of the flight.

Easy boarding with an extremely kind attendant. Seats were spacious and we had 3 seats for 2 people so we could stretch out. Comfortable air flow and very attentive and hospital attendants. Bathrooms and food were the only negative. Bathrooms were so small you could hardly get in and close the door. I don’t think an obese person would fit or a person with a movement disability. Food was the trending food for flights, nonexistent. We spent $40 getting sandwich and snack at airport for our 6 hour flught.

At first, we were on the runway for about an hour, literally. The Captain did explain that the Control Tower just had a change shift (sounds like an unrealistic excuse) and then that we had to change a runway. A regular economy seat is made for 12 yo twiggy. I understand Delta wants to push for an upgrade, but after sitting in a Comfort seat and in First class. I would say First class is not worthy of my money. The landing was delayed because of the weather in NYC, I don't hold that against Delta, of course. The Captain did alert us to that upon takeoff in Vegas and again as we reached NY.

No one fussed at me about my pap machine as a 3rd pice on the plane. Boarding was pleasant and smooth. The boarding agent in Anchorage was a fun character- he could be in a movie. :~) The on-board crew were downright pleasant. No militant attitudes on Delta. Like all planes these days the seats are too narrow for standard Americans and at 5’2” there is barely enough leg room. I don’t know how tall people fold themselves into the seats. But that’s nothing specific to Delta

My husband upgraded our seats and I don't know if it was due to the type of planet was or if they didn't upgrade our seats. We were supposed to be in I believe comfort seats and they were just as tight as any other seat- no leg room and we are very tall people but at least it wasn't extremely cold. My husband did put in a complaint about our seating because he paid extra and if we would have known that the space and the tightness would have been the same, we just would have gotten the emergency row emergency row seats that we normally get. We love Delta but both our flights coming home we're not good. Oh I forgot to mention that on our flight to Hawaii our luggage wheels got broke and we had to purse new luggage on vacation then we never had this problem so we didn't know protocol and reported it after we got home only for them to tell is we only had 24hrs to report the damage. Not sure what was going on with Delta this vacation trip.

My flight was extremely cold. I had a jacket and a cover was left in each seat. The cover was extremely thin and I have a disability, fibromyalgia and arthrithis and AC air is the worst. I closed my vent and my husbands vent and it still was frigid. I asked the attendant if I could get another cover and she quickly almost dismissively and totally unconcerned stating, (I quote) (one per chair) and walked off so quickly that I didn't get a chance to explain to her that I literally have adisability. I didnt want to make a seen so I set on that flight for over 5 hours in pain, joints locking up and extremely uncomfortable. When my fibromyalgia flares up my joints not only ache but they will lock up also and it takes me days to get back to my regular self even though I take medication for it. I felt like it would not have hurt anyone at all for her to just give me an extra cover because I'm sure they have all types of medical issues in people that fly every day.

After all the weather issues at least they got me to my destination the next day

My flight was canceled after being rescheduled for four days canceling my trip. Kayak and everyone affiliated with it I.e the airlines, and just fly have been excruciating to deal with. My trip to visit family had to be canceled as there was no way to make it. I am furious at all of you.

They delayed our flight because of bad weather in NY which was completely understandable. Then they cancelled our flight and a later flight that evening. The earliest we could fly was the next morning. We ended up buying last minute tickets on another airline and made it home slightly delayed but safely that evening. Delta kept saying it was weather related but if that was the case how did we make it back on another airline? The weather in NY was cloudy but not bad.

After a two hour delay, my flight was CANCELLED! No pilot available. Such BS.

Overall very good, only complaint I have is the crew from CLT to SAT could have collected trash sooner.

The AA app really sucks ... Every flight & connecting flights were delayed over 30 mins. One connecting flight on American Eagle said it was delayed in its arrival ... when it was actually parked across from the gate for over 1 hr before they pulled it to the gate. Seats in the economy/ main cabin are packed together like sardines ... no leg room.

Initial flight was cancelled at the time of arrival to the airport, flight alternative requires switching from direct to flight with a layover, and the plane felt like it would split apart, it was so rattle-y.

Amazing food, great staff, with one noticable detail missing ...but no seat entertainment in any of aircraft ...I am not a fan

AA re-routed flight from HNL to LAX due to delay. My group of 3 with reserved seats in row 9 was broken up, with one assigned to a middle seat, another in the last row of the plane. Not happy. No explanation to the delay. No apologies. No compensation. Would have been nice to be offered an Admiral Club admission or a voucher for the extra 3 hours of layover in LAX. Could not hear the boarding gate announcements in LAX. Adjacent gate was boarding at the same time. Loud speakers were competing against each other. Barely made my boarding group.

Boarding gate in Honolulu was staffed with a great clerk with a soothing voice despite the flight delay of over an hour. Flight attendants in the plane were all grumpy, not pleasant looking bunch. Their sour attitude showed throughout the flight. Inly able to get a select few movies started. Most of the movie links in the “free entertainment” did not work.

Above and beyond effort from this crew in a tough situation. So helpful and understanding. Thank you!

The flight delay in Dallas created a domino effect that impacted all connecting flights, leading to an increase in the number of connections. As a result, I missed my flight from Casablanca to Marrakech due to the tight turnaround when landing in Casablanca. CMN Airport was understaffed; only one employee was available to assist passengers while others just stood by and watched. It was an extremely frustrating situation. Many passengers were crying and banging their hands on the counter while talking to customer service representative Allabough. Unfortunately, Allabough couldn’t change my flight in the system. At the same time, I was on the phone with an American Airlines customer service representative named Solomon, who said he couldn’t make the change either. So, I decided to take an ONYA Voyages train from Casablanca to Marrakech to reach my destination on Friday, June 26. It turned out to be an unpredictable trip.

The flight was fine and the crew awesome. The problem is ORD and AA. Computers went down, ORD fell apart and a 40 min flight turned into a 3 hour trip. Guess the answer is to not try and fly to ORD after noon. But, as I said, crew was awesome and did everything they could to lesson the flight time.

I enjoyed my flight, it was pretty smooth and we landed earlier than eta.

Booked through kayak, everything seemed normal but when it came time to go, my flight ticket didn’t exist, so I had to purchase another set of tickets at the airport the day of the flight, for about double. When I reached kayaks customer service, they claimed no responsibility, and pushed me onto another 3rd party booking service, airfare assist, where I have had no luck getting any kind of help or refund. I’ve used kayak many times, but I’ll never again after I’ve been burned by this.

The flight was delayed four and half hours for paperwork on a maintenance issue. Very frustrating.

It was okay delay was long but I made it

Flight was cancelled. No reason given. No apologies. Next available flight is two days later. Ruined our 4th of July plans.

The air fares are good, Charging me for every single thing 😩

It was very bad it got delayed by 2 hours.Never going to travel with spirit airlines in future.

Flight delayed over 3 or 4 hours because no captain to fly plane. I couldn’t make a connection and had to wait 9 hours for another flight. Had to fly red eye flight. Sucks

it was a quick trip. seats aren't that comfortable but because it was a quick trip it was ok. You need to have an N/A in your rating as I didn't have any food or entertainment so the only thing I could do was score low.

We paid for upgrade seats (3A & 3B) the seats on front and the seats behind us got complimentary water & soda, but we got charged, had to pay for everything. Does not make any sense ?

First of all, we never got on the connecting flight to Denver. They delayed our flight for two hours. If we would have gotten on that flight, we would have been stuck in Denver for 13 hours. So we re- routed our flight for a straight through flight to Oklahoma two days later. THEN, they delayed that flight for two hours. After that we were able to finally get on our flight and come home. Frontier Airlines - one of the worst airlines I have ever been on.

Terrible communication with weather delay, lost baggage, near impossible to reach customer service

My tickets got canceled on me by your site and I didn't have a flight. Then you kept sending me emails on the status of q flight I didn't have tickets for.

The delay was ridiculous because nary a word escaped from the gate attendant regarding our flight status. It was a complete joke.

I missed a flight because of a delay. I had to buy a new ticket through Southwest.

The crew was mostly okay. The flight attendant who answered our questions was curt and unhelpful unfortunately. He seemed upset and I understand having off days.

Flight was delayed one hour. Notification to the crowd waiting near the gate was terrible…announcements were unclear and very hard to hear and therefore understand. Frontier does NOT send texts to notify, only email. The reader board over the gate itself was NEVER updated to indicate the gate had been changed. It’s like a bunch of children are running things.

I’m not gonna fly Frontier Airlines because booking is not an option. No water or food is for high price, not equipped for health emergency incompetent crew for emergency services. Cheap airline shows it is cheaper in all service categories. Boarding is the best of all airlines!

We’ve all seen the YouTube vids of out of control passengers. But this was an instance of a highly aggressive, bully flight attendant. Yelling in the face of a vet with PTSD who was texting their family. And no , we had not yet been instructed to put our phones in airplane mode. My suggestion is that you should pay whatever difference there is in order to avoid Frontier airlines. Additionally, after 3hrs trying to get customer service frontier offered a $25 voucher. I declined. This experience was so traumatic. To be verbally assaulted and abused by a flight attendant that has the power to say “boo” and I miss my flight ( which was to a family member’s funeral ). Frontier is unsafe and I cannot impress enough how much I discourage anyone ( esp those with any kind of disability like PTSD ) flying on Frontier.

My flight was delayed by two hours which made it so that I would miss my layover flight. I stood in line for customer service for over an hour and when I reached the agent she told me to scan a QR code and it'll give me options. I wasn't offered any help, guidance or compensation, only told that I have options but that I had to figure it all out myself. I was refunded part of the trip and had to buy an expensive same day ticket from another airline in order to get home. I will never fly Frontier again.

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