$93 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 10/15. 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

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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

Wed, Oct 1 - Thu, Oct 2
 Logo
6:10 am - 9:40 amBOS-STL
28h 30m1 stop
 Logo
4:00 pm - 11:13 amSTL-BOS
18h 13m2 stops
Thu, Oct 9 - Sat, Oct 11
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9:50 am - 10:37 amBOS-STL
25h 47m1 stop
 Logo
7:15 pm - 11:26 amSTL-BOS
15h 11m1 stop
Wed, Feb 25 - Sun, Mar 1
Spirit Airlines Logo
9:48 pm - 11:01 amBOS-STL
14h 13m1 stop
Spirit Airlines Logo
12:20 pm - 12:40 amSTL-BOS
11h 20m1 stop
$275Spirit Airlines
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Sat, Oct 18 - Mon, Oct 20
American Airlines Logo
8:00 am - 4:04 pmBOS-STL
9h 04m1 stop
American Airlines Logo
9:35 am - 1:12 pmSTL-BOS
2h 37mnonstop
$276American Airlines
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Sun, Sep 28 - Thu, Oct 2
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8:47 am - 3:04 pmBOS-STL
31h 17m2 stops
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10:35 am - 11:57 pmSTL-BOS
12h 22m1 stop
Tue, Dec 2 - Sat, Dec 6
American Airlines Logo
6:00 am - 10:18 amBOS-STL
5h 18m1 stop
American Airlines Logo
1:59 pm - 11:59 pmSTL-BOS
9h 00m1 stop
$280American Airlines
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Tue, Sep 30 - Thu, Oct 2
United Airlines Logo
12:10 pm - 4:07 pmBOS-STL
4h 57m1 stop
United Airlines Logo
6:30 am - 12:35 pmSTL-BOS
5h 05m1 stop
$305United Airlines
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Thu, Oct 9 - Sun, Oct 12
Frontier Logo
9:50 am - 10:37 amBOS-STL
25h 47m1 stop
Frontier Logo
11:32 am - 7:27 amSTL-BOS
18h 55m2 stops
$307Frontier
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Thu, Feb 19 - Sat, Feb 21
United Airlines Logo
6:00 am - 10:46 amBOS-STL
5h 46m1 stop
United Airlines Logo
7:00 am - 3:08 pmSTL-BOS
7h 08m1 stop
$319United Airlines
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Sat, Oct 11 - Sun, Oct 12
Spirit Airlines Logo
6:16 am - 6:10 pmBOS-STL
12h 54m1 stop
Spirit Airlines Logo
10:57 am - 11:59 pmSTL-BOS
12h 02m1 stop
$329Spirit Airlines
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Useful Info

Good to know

Low seasonJanuary
Cheapest flight$93
Best time to beat the crowds with an average 9% drop in price.
Most popular time to fly with an average 15% 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 11m.

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

    11 direct flights run between Boston and St. Charles on a daily basis. On average, there are about 80 departures each week.

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

    Consider leaving on a Wednesday and avoid Tuesdays if you are looking for the best rates. For your return to Boston, you’ll find the best rates on Sundays 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 Spirit Airlines for $93. Spirit Airlines offered a round-trip connection from $275 and American Airlines from $276.

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 March, April and May. 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 4242 reviews
8.6Crew
7.5Entertainment
8.1Boarding
8.0Comfort
7.0Food
Airline reviews

I wish they had movie screens in the headrests. The seats are much improved, more legroom and recently renovated. Bathroom was clean. Staff was outstanding!!

10.0 ExcellentG, Sep 2025LAS - ATL
Read more Southwest reviews

I wish they had movie screens in the headrests. The seats are much improved, more legroom and recently renovated. Bathroom was clean. Staff was outstanding!!

As always, the entire Southwest experience was wonderful, from online booking to flight to baggage retrieval. Very grateful.

The weather could have been better. There was a 40 minute ATC delay in SFO because of marine fog and a micro cell storm delayed landing and take-off at Nashville. The gate was changed 5 minutes from boarding from gate B3 to gate C23 at Nashville airport.

After being assaulted by a flight attendant I was then brushed off as oh well because he long braids didn’t mean to whip me in the eye. I have filed complaints and will see. But like any other issue I’ve had with kayak involved it’s been trash. Last time I’ll be using your app

AC sub par. WiFi not working correctly. Ac sucked. Seats very narrow.

Near 4 hour flight with only 1 service. Had to use call button to request water. Internet and power not working until into flight. Internet would stop working during flight.

Southwest's seats are the least comfortable I have ever sat in.

The cabin was quiet for the redeye flight. The area was clean. The staff was great. The 787 Max was in good condition. Drawbacks were that the seat widths were tight for some passengers. The seat padding was at best average and for a long flight uncomfortable.

Southwest like most American domestic airlines, is a mediocre airline. But it is among the cheapest. Oh well.

My flight was delayed 50 minutes and we were rushed to board to then sit for 15 minutes until the pilot arrived. Unacceptable since we could have waited to board. Also the delayed flight was updated AFTER we boarded to more than the 10 minutes as originally stated.

Perfect flight both ways. On time, courteous staff, plane comfortable and cool. Best domestic flights I’ve had in awhile.

Really low quality food especially for an international flight. The crew also was surprisingly unpleasant except couple of ladies. I know we were not in first class but that’s no reason to treat customers as less.

Flight delayed for two and half hours and then canceled altogether due to mechanical issues. No mechanic onsite to fix so had to send one from LAX.

Crew was good. The reservation got mixed up and they didn't have my TSA number. I am also a Silver Medallion and wasn't able to use Sky Priority.

Delta made it easy, comfortable and timely. The crew was fantastic.

This route with Delta always has delays or is cancelled. Aircrafts seem smaller and older. I fly Delta quite a bit - haven’t had issues with the international flights. But this route has always been the troublesome one

Three seats in first class were broken and while they were able to still acommodate us it was looking very touch and go and they had others they could not acommodate

Mechanic delay in addition to a 2 hour change in takeoff time was frustrating.

Delayed due to thunderstorms and no in-flight service due to rough weather — both of which are out of Delta’s control. Flight was good overall.

The flight attendants in SLC were rude. I arrived 40 minutes early to gate. Ticket said I needed check in for seat assignments and tried check in and attendants said they weren’t doing it. And proceeded to never call me to give me a ticket so when time to board I received the very last seat. Please relay to employees to do their job better..,

Given it’s a red-eye into Charolotte, we didn’t get any food. The survey does not include “N/A” so the rating will be skewed.

Great. Quick and quiet and east. The breakfast choices were a welcome surprise!

American airlines suck they delay the flights all the time made me sleep in an airport because my flight was delayed and I miss my connecting flight

There's nothing I liked about it. For first off I scheduled this trip two weeks in advance then they delayed my flight which messed up my whole trip. So I scheduled it for the following weekend thinking there won't be a delay and guess what as soon as I got to the airport we said in the airplane on the tarmac for an hour and a half. Not only was it delayed I missed my connecting flight meaning I had to stay the night at Dallas-Fort Worth airport sleeping on the floor. I will tell you this I will never fly American airlines ever again I have had nothing but horrible experience with them and I just throw money at them

The stewardess hit me with the food kart twice on the head and didn't say I'm sorry once. The same stewardess gave me a warm Apple Juice with No ice. The Flight was delayed for Departure 6 times, starting from 2:36pm, finally taking off 7:50pm. I was late picking up my child from the sitter by 3 hours.

Having to reschedule flights a day later, they loaded by luggage on the wrong plane from Little rock now I have to HOPE they deliver it to where im staying like they said would. International flight crew was very disgruntled and not very friendly.

We will be writing a long, detailed letter to corporate about our awful experience with American airlines.

It took way too long to diagnose and solve the problem of a broken crew member cabin seat. Though compensation for the volunteer who left the flight was very kind.

The entertainment package was vast and the selections were very current. Keep updating it was great.

The seat was so hard my tailbone was aching The crew was kind of a b**** because I made a joke that I didn't care if they close the door I total c*** when she was trying to f****** act like she was mad at me because I said that The flight was bumpy. Sure you didnt have control over that.

Everything was fine. I'm average height and I pack light. I'm ready for my Spirit flight.

Changing the flight time to 6:15 am on the return flight is extremely inconvenient. The flight was okay. It was on time. The crew was friendly. The seats were uncomfortable. All the upsells are annoying, and I would prefer paying a single higher fee and not have to purchase so much extra.

Spirit Airlines was ok but TRAVELHELPDESK, the 3rd party travel agent IS A JOKE! VERY RUDE CUSTOMER AGENTS ont he phone. NO HELP AT ALL. But the airlines was ok.

Cancelled my flight last minute and did not help me rebook. It was a horrible experience.

No frills - because you get what you pay for. The crew was amazing!! I had plenty of room to spread out because the flight was half full. Which made it easy to sleep.

The terminal crew is so rude cabin crew is extremely rude flight is very good

Spirit is low fare air line. Food also cost you. No free food.

The flight was delayed twice with minimal explanation. The terminal and airplane were filthy. The food voucher didn’t even cover a tiny pizza from a kiosk in the terminal. All in all, a pretty miserable experience for a flight to attend a funeral

I will use spirit more New clean aircraft Excellent crew ! Quick boarding process !

Everyone was kind for the most part. I did travel with children and paid for seats and even then it was not as suitable. I tried calling their customer service prior to check in and I was told they couldn't help me because I didn't purchase my tickets with them.

Seats were new and comfortable. Staff was fine. Missed my connection due to weather -which wasn’t their fault- but got no help at all. Gate staff sent me to customer service, which was and stayed unstaffed. Sign with QR code directed me to call or chat. Chat was useless. Call was returned after an hour. No itinerary offered by Frontier could get me home in less than 30 hours. Rebooked with another airline and got a partial refund that came to about 10 percent of what I paid to get home.

Finally a Frontier on time and efficient. I've had problems before with your airline, but this time everything went fine.

The experience was good. No frills but I got there safe and sound and on time.

Great for the price. No wifi or entertainment, but gate agents and crew were fantastic and we boarded quickly and left on time.

sluggish boarding and arrival procedures, fake nice flight attendants, and lots of delays.

Disaster. They lied every step of the way. We ended up being delayed due to crew and then allegedly abandoned the flight because of a curfew at LGA. No rebooking to LGA at any reasonable time. No hotel. No meal vouchers. Had to sleep in the airport and fly to Newark instead. Will never fly Frontier again.

What I expected, nickeled and dined and a frontier flight attendant loudly complained about her job and lack of communication as she headed to the gate on her cell phone. Not professional.

As every law enforcement agency I could imagine surrounded the plane and we didn’t disembark for 2 hours and then had to stick around for another hour to go get our personal belongings after leaving them behind and being bused away from the plane, it was scary and inconvenient. We were given no information as to why this was happening. Lack of communication with passengers was disappointing.

After boarding and un-boarding twice over 6+hours, the flight was canceled.

Severe turbulence. Captain never came on to reassure passengers after things settled down.

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

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