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Find cheap flights from Boston to St. Charles from $86

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 7/9. 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.
1 adult
0 bags
Wed 7/10
Wed 7/17

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Good to know

Low season

January

High season

May

Cheapest flight

$86
Best time to beat the crowds with an average 14% drop in price.
Most popular time to fly with an average 7% 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 00m.

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

    6 direct flights run between Boston and St. Charles on a daily basis. On average, there are about 47 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 Thursdays if you are looking for the best rates. For your return to Boston, you’ll find the best rates on Mondays and the most expensive ones on Thursdays.

  • 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 $86. Frontier offered a round-trip connection from $151 and Spirit Airlines from $165.

See more FAQs

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 81 days before departure, on average.
  • Book at least 3 weeks before departure in order to get a below-average price.
  • High season is considered to be May, June and July. The cheapest month to fly is February.
See more tips

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
DeltaOverall score based on 10295 reviews
8.6Crew
7.4Food
8.2Boarding
7.9Comfort
8.0Entertainment
Airline reviews

3 hours late and all they have is was a $12 meal voucher. That’s not even enough to cover fast food.

2.0 MediocreCraig, Jun 2024CVG - LGA
Read more about Delta reviews

3 hours late and all they have is was a $12 meal voucher. That’s not even enough to cover fast food.

Among the poorest flights I’ve had with Delta in a while. Entertainment system failed completely on a 7.5 hr flight. Crew seemed distracted and not the normal friendly crew. Flight overbooked it seemed… very crowded.

If I can, I always fly Delta. I’ve found their service to always be reliable and pleasant.

You could have not cancelled the flight (AA, which I will be flying from now on) left for BOS despite the fictitious weather issues (that no one in my Boston family could see). You could have rebooked my direct flight to another direct flight instead of sending me though JFK, the worst US airport after O’Hara You could have rebooked me on a Main Cabin seat (like the one I paid for in my original ticket instead of putting me a the last row on JFK->BOS leg, pocketing the difference in ticket price But I do not really care whether you will ever do that in a future because in a future neither I nor anyone from my company (unless they pay out of pocket) nor an of my clients and partners (if they heed my advice) will ever be caught dead on any of Delta flights

Really bad baggage handling. Had my Rimowa bag badly damaged at the latches.

It was pretty good I was worried with the short Layover that I might not catch my connection but the gate was there

It was good until there was a 3 hour delay because there was not any pilots to fly the plane.

There was plenty of overhead room but half of the passengers were told they had to check their carryon bags. My partner and I checked in as early as possible and our seats were split across the aisle.

Friendly flight attendants. Comfort plus seats were very comfortable and had lots of leg room. 10A and 10 B.

Flew first class so everything was great. But maybe because the flights were red eye, no meals were served, just chips. I flew Alaska Air 1st class at 9PM (2 hour flight) and they served beef short rib sliders!

Overall fine but both ways for this trip was delayed.

I had back trouble prior to my flight and everyone was great about helping me.

My tv was broken on the flight which is disappointing when you pay for a seat and expect a service

Always delays from Boston to Salt lake but this time was very long. Don’t understand while they board the passengers and then make them sit in the plane

Service for food to our seat was a bit slow. Snack choices were just pretzels or baked chips. My seat cushion was not attached. Other than Barbie, video choice were not very good or current.

After we landed, we were held on the plane for 30 minutes. There was no one at the gate once we landed and we forced to sit on a plan that had already over an hour delayed.

almost 4 hour delay as they over booked and had to wait for 8-10 volunteers to agree to travel next day.

Old plane. No outlets for laptop or phone. Seats worn out. Area around seat dirty.

I loved the flight and the crew. It was comfortable and smooth.

The crew was openly hostile and condescending to the customers. They spent the majority of that time in the rear talking and seemed really agitated when people asked questions. I heard five different people told that the information they requested was in the handout or safety brief.

It is a modern tragedy that any airline expects you to travel for 14 hours in such discomfort and that the only way to add comfort is exorbitant prices. I was in pain by the time we landed. Shameful.

Original plane sidelined. Had to wait an hour for replacement.

Crew was very cooperative and professional. Passenger's first checked in bag should be free.

No real agent onsite helping you for missing luggage there. Not like the other airline next to UA desk, they have staff attending in their desk assisting answer/helping luggage issue, even after midnight.

Horrible, the flights kept delaying, so it is obvious that we won't be able to make it to the next connection. No easier/real agent on site to help you figure this out. UA agent on other counters refuse to assist you and direct us to use the QR code/call customer service. So inefficient and poor. While technology seems convenient, but it's not the best interest/experience for customers need help while there is active issue need assistance.

After the morning frenzy of 35 min wait through CLT security at 4;30 AM, it was nice to have a smooth pleasant boarding experience. This 6:30 AM flight was not full. We were able to get seated swiftly and took off promptly. Nice touch they distributed the old fashioned headsets with 8 mm jacks. Snacks were decent and arrival was uneventful.

My window shade didn’t work. So I missed coming into my city. ☹️

Flight was delayed in the gate by 5 hours and ultimately cancelled- rebooking service by United agents was terrible

Flight was delayed due to the late arrival of the catering truck, which is quite unacceptable. There was a beverage service, but no pretzel, or cookie, or nuts were served in coach.

Not worth the price of premium class ticket paid, felt more like steerage.

Paid for premium economy had no tv the whole time the crew tried to reset/reboot but would not work they said they would put a trouble ticket in for it. We had 3 seats my tv was the only one that didn't work. They cancelled our flight re worked us on another that left us at airport over night on the floor I have a ten year old and a 78 diabetic mother which also had shingles and suffers from nerve pain in legs and back. Requested wheelchair service at all airports after the re route NO wheelchair service was there to help. WORST experience we have ever had. Went to American airlines assistance it was closed. I AM FURIOUS!!! I expect some sort of compensation from this traumatic experience and no need for flying points we don't plan on using American airlines again!!!!

This is by far the worst experience I have had with American Airlines. The start of this trip was a complete disaster. I purposely planned my trip so that I would weather any delays so that I could make very important meeting at the Pentagon. My flight was cancelled because of maintenance and I was put on the first flight the next day but I was late to the meeting. After a long week at the Pentagon I just wanted to go home and my flight home which was early in the day was delayed. Eventually the flight was delayed until the next day. I was not authorized a hotel room because DCA was my point of origin. So I paid for a hotel out of pocket. The flight this morning was boarded then deplaned because the aircraft was hot. The flow of information was not happening in DCA and made it worse when the news was bad. I am going to take a break from American for my next few military flights. Hopefully whatever has been going on with American Airlines will be resolved.

We had a 2 hour delay. The seats were smaller than most other airlines. The person in front of us wanted to lay back and we had to stop her because she was pressing against my girlfriend’s legs. We had to ask her to sit up and not lay back due to the lack of room.

Everything was fine once we actually got on our flight. It was more then annoying they canceled (delayed) our flight. We lost out on a day of our trip along with money on our stay. Plus we had to book another hotel. So expensive.

This flight was canceled and delayed several times without explanation. The plane was freezing cold and no wifi for messaging. Getting off the plane was terribly unorganized and felt like it took forever….

The flight was delayed several times without explanation. The seats were terribly uncomfortable and wifi isn’t included. All these make for a less than ideal flight.

The flights was delayed by hours and it was the firmest landing I have experienced in my life. My back is still sore.

Internet service was erratic. Crew service was poor and slow. My luggage on this non-stop flight was lost and not recovered

Worst experience flying American Airlines. I fly with them often, so I was super disappointed in the service I received at gate 30 in LGA on May 24, mid-day. The flight was delayed twice. I was patiently waiting in the American Airlines lounge when I received the notice on my app that the plane was boarding 45 minutes before its newly re-scheduled take off of 4 pm (from the orginal 1:45 pm then 3:00 pm). It took me 5 min to travel from the lounge to the gate and when I arrived there at 3:20 flight gate attendant told me the flight had closed and that they announced for passengers multiple times. I showed them the notification on my app and they were really rude and unempathetic. The person who rescheduled my flight at customer service wasn't any happier but was at least helpful in getting me on the next flight.

Flight delayed, boarding time kept changing, not good. Nee firm information given each time.

I strongly dislike Frontier. I find them barebones, the seats not particularly comfortable, the nickel and diming is maddening, the app is TERRIBLE - super confusing to navigate, and the last 4 frontier flights I have flown have been on AVERAGE 2 hours late, one ruining a fancy night out in Vegas with reservations made well in advance, which was nodded to with a measly 5000 miles, which translates to almost nothing. At least credit a free checked bag or something.

8 hr delay. had to buy another ticket with another airline

Four and a half hour delay in total. What frustrates me most is the poor communication and disorganization.

I appreciated the upgrade to free cary-on bag and seat selection at no charge

FRONTIER SUCKS! The agent downstairs tricked me into booking, just to get to the gate. At the gate, they told me they couldn't help. I then called Customer Service. They and the gate attendants kept blaming each other. Neither side was willing to help the customer.

The agent at check-in was strident, unwelcoming, and condescending to customers ahead of me.

Flight was delay 9hrs and nothing was provided at airport, had to go and get a room to sleep in, paid for Uber back and fort with no offers until we landed back home a 1hr later for a $75 voucher for a future flight.

Didn't like anything..entire crew was very rude to everyone on the flight. Plane old and the trays fall down on you the while time you're flying. Charged more for a carry on bag than for the plane ticket itself. Did make it from point a to point b, but worth the extra money to fly with another airline

9 hours of delay!! Was not able to check my luggage that I paid for!!!

It was delayed 9 hours for operational reasons, despite the plane arriving to the airport on time.

Book cheap flights from Boston to St. Charles

Recent round-trip flight deals

7/31Wed
1 stopFrontier
9h 10mBOS-STL
8/3Sat
1 stopFrontier
8h 18mSTL-BOS
$151
7/10Wed
1 stopFrontier
9h 10mBOS-STL
7/12Fri
1 stopFrontier
12h 55mSTL-BOS
$152
7/6Sat
1 stopFrontier
6h 13mBOS-STL
7/13Sat
1 stopFrontier
8h 18mSTL-BOS
$158
9/7Sat
1 stopSpirit Airlines
11h 10mBOS-STL
9/11Wed
1 stopSpirit Airlines
6h 22mSTL-BOS
$165
9/5Thu
1 stopSpirit Airlines
11h 10mBOS-STL
9/8Sun
1 stopSpirit Airlines
25h 09mSTL-BOS
$186
7/1Mon
1 stopAmerican Airlines
8h 41mBOS-STL
7/2Tue
1 stopAmerican Airlines
8h 00mSTL-BOS
$254
7/1Mon
1 stopAmerican Airlines
8h 41mBOS-STL
7/4Thu
1 stopAmerican Airlines
9h 48mSTL-BOS
$265
7/9Tue
1 stopDelta
7h 00mBOS-STL
7/15Mon
1 stopDelta
6h 37mSTL-BOS
$279
8/15Thu
1 stopDelta
7h 00mBOS-STL
10/5Sat
1 stopDelta
8h 04mSTL-BOS
$294
7/1Mon
2 stopsUnited Airlines
7h 40mBOS-STL
7/3Wed
1 stopUnited Airlines
6h 07mSTL-BOS
$299

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Recent one-way flight deals

7/9Tue
1 stopSpirit Airlines
9h 13mBOS-STL
$86
7/12Fri
1 stopFrontier
9h 10mBOS-STL
$93
7/11Thu
2 stops
30h 10mBOS-STL
$115
7/12Fri
3 stops
29h 45mBOS-STL
$124
7/23Tue
1 stopAmerican Airlines
8h 32mBOS-STL
$127
10/30Wed
1 stopDelta
6h 09mBOS-STL
$132
7/2Tue
1 stopAmerican Airlines
8h 46mBOS-STL
$140
8/15Thu
1 stopUnited Airlines
4h 48mBOS-STL
$147
6/16Sun
1 stopDelta
4h 55mBOS-STL
$149
8/15Thu
2 stopsUnited Airlines
9h 48mBOS-STL
$192

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Last minute flights from Boston to St. Charles

Last minute flight, train and bus deals

6/12Wed
multi-stopFrontier
22h 51mBOS-STL
6/21Fri
multi-stopFrontier
7h 22mSTL-BOS
$272
6/12Wed
multi-stopFrontier
22h 51mBOS-STL
6/20Thu
multi-stopFrontier
11h 32mSTL-BOS
$279
6/15Sat
multi-stopDelta
7h 47mBOS-STL
6/18Tue
multi-stopDelta
4h 32mSTL-BOS
$316
6/13Thu
multi-stopUnited Airlines
7h 56mBOS-STL
6/18Tue
multi-stopUnited Airlines
6h 07mSTL-BOS
$321
6/14Fri
multi-stopUnited Airlines
6h 51mBOS-STL
6/16Sun
multi-stopUnited Airlines
6h 07mSTL-BOS
$344
6/12Wed
multi-stopDelta
5h 19mBOS-STL
6/19Wed
multi-stopDelta
5h 20mSTL-BOS
$367
6/13Thu
multi-stopSpirit Airlines
8h 15mBOS-STL
6/18Tue
multi-stopSpirit Airlines
19h 41mSTL-BOS
$422
6/13Thu
multi-stopSpirit Airlines
8h 15mBOS-STL
6/20Thu
multi-stopSpirit Airlines
23h 08mSTL-BOS
$465
6/15Sat
multi-stopAmerican Airlines
7h 40mBOS-STL
6/19Wed
nonstopAmerican Airlines
2h 43mSTL-BOS
$677
6/12Wed
multi-stopAmerican Airlines
5h 10mBOS-STL
6/27Thu
nonstopAmerican Airlines
2h 43mSTL-BOS
$686

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Flights to St. Charles