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Cheap flights from Boston to St. Louis from $78

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Boston to St. Louis departing on 3/3. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
0 bags

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Find the cheapest flights from Boston to St. Louis

Cheap round-trip flights

Enter your travel dates to find the best prices.
American Airlines Logo
12:22 pm - 10:17 pm
BOS
-
STL
10h 55m
1 stop
American Airlines Logo
12:25 pm - 12:23 am
STL
-
BOS
10h 58m
1 stop
$353American Airlines
Tue, Apr 7 - Sat, Apr 11
Southwest Logo
5:25 pm - 7:35 pm
BOS
-
STL
3h 10mnonstop
Southwest Logo
1:25 pm - 4:55 pm
STL
-
BOS
2h 30mnonstop
$354Southwest
Wed, Mar 11 - Thu, Mar 12
Frontier Logo
10:01 am - 6:51 am
BOS
-
STL
21h 50m
2 stops
Frontier Logo
8:20 pm - 12:29 am
STL
-
BOS
27h 09m
1 stop
$356Frontier
Thu, Feb 19 - Fri, Feb 20
Multiple Airlines Logo
4:23 pm - 11:55 pm
BOS
-
STL
8h 32m
1 stop
Multiple Airlines Logo
4:54 pm - 10:31 am
STL
-
BOS
16h 37m
1 stop
$357Multiple Airlines
Fri, Apr 3 - Wed, Apr 8
Multiple Airlines Logo
11:45 am - 11:59 pm
BOS
-
STL
13h 14m
1 stop
Multiple Airlines Logo
2:47 pm - 6:54 am
STL
-
BOS
15h 07m
1 stop
$358Multiple Airlines
Thu, Feb 19 - Thu, Feb 26
Multiple Airlines Logo
4:23 pm - 11:19 pm
BOS
-
STL
7h 56m
1 stop
Multiple Airlines Logo
10:47 pm - 11:41 am
STL
-
BOS
35h 54m
2 stops
$360Multiple Airlines
Thu, Mar 12 - Sun, Mar 15
Southwest Logo
6:25 am - 8:45 am
BOS
-
STL
3h 20mnonstop
Southwest Logo
4:00 pm - 9:25 pm
STL
-
BOS
4h 25m
1 stop
$361Southwest
Wed, Mar 4 - Wed, Mar 11
Southwest Logo
8:45 pm - 7:45 am
BOS
-
STL
12h 00m
1 stop
Southwest Logo
7:45 am - 5:55 pm
STL
-
BOS
9h 10m
2 stops
$362Southwest
Sat, Mar 21 - Sat, Mar 28
Southwest Logo
6:00 pm - 10:00 pm
BOS
-
STL
5h 00m
1 stop
Southwest Logo
6:55 pm - 10:25 pm
STL
-
BOS
2h 30mnonstop
$364Southwest
Tue, Apr 14 - Sat, Apr 18
Southwest Logo
5:15 am - 7:25 am
BOS
-
STL
3h 10mnonstop
Southwest Logo
7:40 pm - 11:05 pm
STL
-
BOS
2h 25mnonstop
$365Southwest
Thu, Mar 26 - Sat, Mar 28

American Airlines flights from Boston to St. Louis

Our best American Airlines deals on Boston to St. Louis flight tickets
American Airlines
Apr 7
BOS12:22 pmBoston Logan Intl
10h 55m
1 stop
STL10:17 pmLambert-St Louis
Apr 11
STL12:25 pmLambert-St Louis
10h 58m
1 stop
BOS12:23 amBoston Logan Intl
$353
American Airlines
Apr 19
BOS9:00 amBoston Logan Intl
3h 13m
STL11:13 amLambert-St Louis
Apr 19
STL12:25 pmLambert-St Louis
7h 47m
1 stop
BOS9:12 pmBoston Logan Intl
$369
American Airlines
Apr 1
BOS9:05 amBoston Logan Intl
3h 24m
STL11:29 amLambert-St Louis
Apr 11
STL8:54 amLambert-St Louis
8h 56m
1 stop
BOS6:50 pmBoston Logan Intl
$370

Southwest flights from Boston to St. Louis

Our best Southwest deals on Boston to St. Louis flight tickets
Southwest
Mar 11
BOS5:25 pmBoston Logan Intl
3h 10m
STL7:35 pmLambert-St Louis
Mar 12
STL1:25 pmLambert-St Louis
2h 30m
BOS4:55 pmBoston Logan Intl
$354
Southwest
Mar 4
BOS6:25 amBoston Logan Intl
3h 20m
STL8:45 amLambert-St Louis
Mar 11
STL4:00 pmLambert-St Louis
4h 25m
1 stop
BOS9:25 pmBoston Logan Intl
$361
Southwest
Apr 14
BOS6:00 pmBoston Logan Intl
5h 00m
1 stop
STL10:00 pmLambert-St Louis
Apr 18
STL6:55 pmLambert-St Louis
2h 30m
BOS10:25 pmBoston Logan Intl
$364

momondo Fare Finder

 
Customize your flight search to find flights from Boston to St. Louis 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, momondo users made 832,500 searches. Data last updated February 8, 2026.
Use the filters below to find and compare flights from Boston to St. Louis that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Tue 4/7

12:22 pm-10:17 pm

1 stop10h 55m

Lambert-St Louis

Sat 4/11

12:25 pm-12:23 am

1 stop10h 58m

$353

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Wed 3/11

5:25 pm-7:35 pm

Nonstop3h 10m

Lambert-St Louis

Thu 3/12

1:25 pm-4:55 pm

Nonstop2h 30m

$354

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Thu 2/19

10:01 am-6:51 am

2 stops21h 50m

Lambert-St Louis

Fri 2/20

8:20 pm-12:29 am

1 stop27h 09m

$356

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Fri 4/3

4:23 pm-11:55 pm

1 stop8h 32m

Lambert-St Louis

Wed 4/8

4:54 pm-10:31 am

1 stop16h 37m

$357

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Thu 2/19

11:45 am-11:59 pm

1 stop13h 14m

Lambert-St Louis

Thu 2/26

2:47 pm-6:54 am

1 stop15h 07m

$358

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Thu 3/12

4:23 pm-11:19 pm

1 stop7h 56m

Lambert-St Louis

Sun 3/15

10:47 pm-11:41 am

2 stops35h 54m

$360

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Wed 3/4

6:25 am-8:45 am

Nonstop3h 20m

Lambert-St Louis

Wed 3/11

4:00 pm-9:25 pm

1 stop4h 25m

$361

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Sat 3/21

8:45 pm-7:45 am

1 stop12h 00m

Lambert-St Louis

Sat 3/28

7:45 am-5:55 pm

2 stops9h 10m

$362

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Tue 4/14

6:00 pm-10:00 pm

1 stop5h 00m

Lambert-St Louis

Sat 4/18

6:55 pm-10:25 pm

Nonstop2h 30m

$364

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Thu 3/26

5:15 am-7:25 am

Nonstop3h 10m

Lambert-St Louis

Sat 3/28

7:40 pm-11:05 pm

Nonstop2h 25m

$365

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to St. Louis from

How to get the cheapest flight ticket from Boston to St. Louis

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest month to fly to St. Louis?

In general, August is the cheapest month to fly from Boston to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $382. The month of September is another great option to travel to St. Louis, with average flight prices from Boston averaging around $401.

What is the cheapest day to depart on your flight to St. Louis?

The cheapest day to depart on your flight to St. Louis is on a Wednesday when prices can be found for as low as $423. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Sunday because tickets tend to average around $498. These prices are subject to change though, so be sure to set up a Price Alert for flights to St. Louis.

What is the cheapest time of day to depart on your flight to St. Louis?

Flying to St. Louis from Boston in the evening is the least expensive time of day to depart. momondo users have found prices as low as $431 when looking at flights departing in the evening. At noon is when there is more demand to fly to St. Louis, so prices are often more expensive at around $464 per ticket.

What is the cheapest Boston Logan Intl to Lambert-St Louis flight route?

Fly from Boston Logan Intl to Lambert-St Louis for the best Boston Logan Intl - Lambert-St Louis flight prices

How far in advance should I book a flight to St. Louis?

You are more likely to see cheaper flights to St. Louis from Boston when booking weeks ahead of your departure date. In general, you can expect to find flights to St. Louis for around $453 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to St. Louis from Boston for as low as $384 on momondo.

What cabin class options are available on Boston Logan Intl to Lambert-St Louis flights?

There are 3 cabin classes available to choose from on Boston Logan Intl to Lambert-St Louis flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Can stopping save me money on Boston to St. Louis flights?

You could potentially save up to 18% on your flight if you consider stops on a Boston to St. Louis flight.

How have Boston to St. Louis flight prices changed over time?

As of February 2026, prices for Boston to St. Louis flights are approximately 49% more expensive when compared to flights at the same time last year.

When to book flights from Boston to St. Louis

Are you open to changing your travel dates? Check out the ideal times to fly from Boston to St. Louis according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Boston to St. Louis (BOS to STL) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Boston to St. Louis

Best Price Found

$206

Fastest flight time

2h 50m

Direct flights

Every day

Airports in St. Louis

1 airport
The best one-way flight to St. Louis from Boston in the past 72 hours is $206. The best round-trip flight deal from Boston to St. Louis found on momondo in the last 72 hours is $379.
The fastest flight from Boston to St. Louis takes 2h 50m
Direct flights go from Boston to St. Louis every day.
There is 1 airport in St. Louis. From Boston there are direct flights to Lambert-St Louis (STL).
Search flight deals

  • How far is Boston Logan Intl to Lambert-St Louis by plane?

    Lambert-St Louis is 1035.0 mi away from Boston Logan Intl. Flights usually cover this in 2h 50m, depending on flying conditions and air traffic around both airports.

  • When did momondo last update prices for flights from Boston Logan Intl Airport to Lambert-St Louis Airport?

    Prices for flights from Boston Logan Intl Airport to Lambert-St Louis Airport were last updated today.

  • How many operators does momondo search for flights from Boston Logan Intl Airport to Lambert-St Louis Airport?

  • How old do you have to be to fly from Boston Logan Intl Airport to Lambert-St Louis Airport?

    The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Boston Logan Intl Airport to Lambert-St Louis Airport.

  • What documentation or ID do you need to fly to Lambert-St Louis Airport?

    The travel and health documents you'll need for your trip to Lambert-St Louis Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Lambert-St Louis Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

  • What is the most popular plane model from Boston to St. Louis?

  • What is the most popular airline from Boston to St. Louis?

Best airlines flying from Boston to St. Louis

Compare and see reviews for airlines that fly from Boston to St. Louis with momondo
Airline
Rating
Free Cancellation
Price
Spirit AirlinesPriceFrom $63Free CancellationRating
6.3
8,430 reviews
Search Spirit Airlines flights
FrontierPriceFrom $90Free CancellationRating
5.7
3,051 reviews
Search Frontier flights
DeltaPriceFrom $154Free CancellationRating
7.9
8,174 reviews
Search Delta flights
American AirlinesPriceFrom $288Free CancellationRating
7.2
11,258 reviews
Search American Airlines flights
United AirlinesPriceFrom $292Free CancellationRating
7.4
9,259 reviews
Search United Airlines flights
SouthwestPriceFrom $319Free CancellationRating
8.0
4,282 reviews
Search Southwest flights
JetBluePriceFrom $385Free CancellationRating
7.2
2,895 reviews
Search JetBlue flights

  • Southwest Flights From Boston to St. Louis

    Southwest operates around 7 flights from Boston to St. Louis every week. The average price of these flights found in the last 72 hours has been $470, but momondo users have found Southwest deals from Boston to St. Louis from as low as $319 round-trip. Southwest has been scored 8.0/10 in 4,282 reviews.

  • American Airlines Flights From Boston to St. Louis

    The best American Airlines deal for Boston to St. Louis flight tickets found on momondo in the last 72 hours was $288, round-trip. It should be noted that an average American Airlines flight deal for this route in this time was higher, at $453 round-trip. American Airlines operates 11 flights out of Boston into St. Louis in an average week, so prices vary by time and availability. 11,258 American Airlines reviews by users on momondo have scored the airline at 7.2/10.

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
St. Charles
Chesterfield
Hermann
Fairview Heights
Maryland Heights
Florissant
O'Fallon
Collinsville
St. Peters
Fenton
Wentzville
Alton
Farmington
Clayton
Edwardsville
Eureka
Festus
Litchfield
Glencoe
Shrewsbury

Why use momondo?

Why should I use momondo to find a flight deal from Boston to St. Louis?

We help find the flight that best suits your needs, momondo compares prices from hundreds of airlines and travel agents and helps you filter them to find the best flight from Boston to St. Louis for you.

Can I find flights from Boston to St. Louis with flexible booking policies on momondo?

Yes. All flights to St. Louis from Boston on momondo can be compared and filtered by various policies on offer, including flexible booking.

How can momondo help me find flights from Boston to St. Louis?

momondo helps you find the best flight between Boston and St. Louis by providing filters to narrow your choice of flights to those matching your criteria. You can select flights based on numerous factors such as price, departure and landing times, airport and airline.

I’m not ready to book a flight from Boston to St. Louis right now. Can momondo alert me if prices change?

Yes momondo offers price alerts on flights to St. Louis from Boston. After performing a search on this page you should be able to see the price alert set up feature. Simply provide a valid email address and momondo will instantly alert you when prices change.

An easier way to manage your St. Louis trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.
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