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Cheap flights from Boston to St. Louis from $70

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 1/28. 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.
Southwest Logo
7:10 am - 9:30 am
BOS
-
STL
3h 20mnonstop
Southwest Logo
8:45 am - 12:20 pm
STL
-
BOS
2h 35mnonstop
$346Southwest
Sat, Jan 17 - Sat, Jan 24
American Airlines Logo
1:00 pm - 8:16 pm
BOS
-
STL
8h 16m1 stop
American Airlines Logo
6:00 am - 3:17 pm
STL
-
BOS
8h 17m1 stop
$347American Airlines
Thu, Feb 12 - Mon, Feb 16
Southwest Logo
5:00 pm - 7:15 pm
BOS
-
STL
3h 15mnonstop
Southwest Logo
5:55 pm - 9:25 pm
STL
-
BOS
2h 30mnonstop
$348Southwest
Fri, Feb 6 - Tue, Feb 10
Southwest Logo
2:25 pm - 10:00 pm
BOS
-
STL
8h 35m2 stops
Southwest Logo
7:35 am - 3:55 pm
STL
-
BOS
7h 20m2 stops
$349Southwest
Wed, Apr 8 - Tue, Apr 14
Frontier Logo
10:01 am - 11:59 pm
BOS
-
STL
14h 58m2 stops
Frontier Logo
8:22 pm - 1:13 am
STL
-
BOS
27h 51m1 stop
$350Frontier
Thu, Feb 12 - Mon, Feb 16
American Airlines Logo
6:30 am - 9:03 am
BOS
-
STL
3h 33mnonstop
American Airlines Logo
12:06 pm - 3:45 pm
STL
-
BOS
2h 39mnonstop
$351American Airlines
Sat, Jan 31 - Sat, Feb 7
American Airlines Logo
1:40 pm - 9:51 pm
BOS
-
STL
9h 11m1 stop
American Airlines Logo
12:11 pm - 3:50 pm
STL
-
BOS
2h 39mnonstop
$353American Airlines
Thu, Jan 29 - Mon, Feb 2
American Airlines Logo
9:00 am - 11:16 am
BOS
-
STL
3h 16mnonstop
American Airlines Logo
11:50 am - 3:30 pm
STL
-
BOS
2h 40mnonstop
$355American Airlines
Sat, Feb 14 - Sat, Feb 21
Southwest Logo
7:10 am - 9:30 am
BOS
-
STL
3h 20mnonstop
Southwest Logo
8:50 am - 4:10 pm
STL
-
BOS
6h 20m1 stop
$356Southwest
Sat, Jan 17 - Sat, Jan 24
Southwest Logo
6:35 am - 8:55 am
BOS
-
STL
3h 20mnonstop
Southwest Logo
6:50 am - 12:25 pm
STL
-
BOS
4h 35m1 stop
$358Southwest
Fri, Feb 6 - Tue, Feb 10

American Airlines flights from Boston to St. Louis

Our best American Airlines deals on Boston to St. Louis flight tickets
American Airlines
Feb 12
BOS1:00 pmBoston Logan Intl
8h 16m
1 stop
STL8:16 pmLambert-St Louis
Feb 16
STL6:00 amLambert-St Louis
8h 17m
1 stop
BOS3:17 pmBoston Logan Intl
$347
Find similar
American Airlines
Jan 31
BOS6:30 amBoston Logan Intl
3h 33m
STL9:03 amLambert-St Louis
Feb 7
STL12:06 pmLambert-St Louis
2h 39m
BOS3:45 pmBoston Logan Intl
$351
Find similar
American Airlines
Jan 29
BOS1:40 pmBoston Logan Intl
9h 11m
1 stop
STL9:51 pmLambert-St Louis
Feb 2
STL12:11 pmLambert-St Louis
2h 39m
BOS3:50 pmBoston Logan Intl
$353
Find similar

Southwest flights from Boston to St. Louis

Our best Southwest deals on Boston to St. Louis flight tickets
Southwest
Jan 17
BOS7:10 amBoston Logan Intl
3h 20m
STL9:30 amLambert-St Louis
Jan 24
STL8:45 amLambert-St Louis
2h 35m
BOS12:20 pmBoston Logan Intl
$346
Find similar
Southwest
Feb 6
BOS5:00 pmBoston Logan Intl
3h 15m
STL7:15 pmLambert-St Louis
Feb 10
STL5:55 pmLambert-St Louis
2h 30m
BOS9:25 pmBoston Logan Intl
$348
Find similar
Southwest
Apr 8
BOS2:25 pmBoston Logan Intl
8h 35m
2 stops
STL10:00 pmLambert-St Louis
Apr 14
STL7:35 amLambert-St Louis
7h 20m
2 stops
BOS3:55 pmBoston Logan Intl
$349
Find similar

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 January 6, 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

Sat 1/17

7:10 am-9:30 am

Nonstop3h 20m

Lambert-St Louis

Sat 1/24

8:45 am-12:20 pm

Nonstop2h 35m

$346

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Thu 2/12

1:00 pm-8:16 pm

1 stop8h 16m

Lambert-St Louis

Mon 2/16

6:00 am-3:17 pm

1 stop8h 17m

$347

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Fri 2/6

5:00 pm-7:15 pm

Nonstop3h 15m

Lambert-St Louis

Tue 2/10

5:55 pm-9:25 pm

Nonstop2h 30m

$348

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Wed 4/8

2:25 pm-10:00 pm

2 stops8h 35m

Lambert-St Louis

Tue 4/14

7:35 am-3:55 pm

2 stops7h 20m

$349

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Thu 2/12

10:01 am-11:59 pm

2 stops14h 58m

Lambert-St Louis

Mon 2/16

8:22 pm-1:13 am

1 stop27h 51m

$350

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Sat 1/31

6:30 am-9:03 am

Nonstop3h 33m

Lambert-St Louis

Sat 2/7

12:06 pm-3:45 pm

Nonstop2h 39m

$351

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Thu 1/29

1:40 pm-9:51 pm

1 stop9h 11m

Lambert-St Louis

Mon 2/2

12:11 pm-3:50 pm

Nonstop2h 39m

$353

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Sat 2/14

9:00 am-11:16 am

Nonstop3h 16m

Lambert-St Louis

Sat 2/21

11:50 am-3:30 pm

Nonstop2h 40m

$355

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Sat 1/17

7:10 am-9:30 am

Nonstop3h 20m

Lambert-St Louis

Sat 1/24

8:50 am-4:10 pm

1 stop6h 20m

$356

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Fri 2/6

6:35 am-8:55 am

Nonstop3h 20m

Lambert-St Louis

Tue 2/10

6:50 am-12:25 pm

1 stop4h 35m

$358

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 typical price of a round-trip flight between Boston and St. Louis?

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 $387.

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 $501. 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 $435 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 $462 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 $447 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 39% 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 January 2026, prices for Boston to St. Louis flights are approximately 7% 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

$220

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 $220. The best round-trip flight deal from Boston to St. Louis found on momondo in the last 72 hours is $382.
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 $71Free CancellationRating
6.3
8,273 reviews
Search Spirit Airlines flights
FrontierPriceFrom $90Free CancellationRating
5.7
3,064 reviews
Search Frontier flights
DeltaPriceFrom $216Free CancellationRating
7.9
8,017 reviews
Search Delta flights
American AirlinesPriceFrom $290Free CancellationRating
7.2
11,082 reviews
Search American Airlines flights
United AirlinesPriceFrom $292Free CancellationRating
7.4
9,132 reviews
Search United Airlines flights
SouthwestPriceFrom $321Free CancellationRating
8.0
4,247 reviews
Search Southwest flights

  • Southwest Flights From Boston to St. Louis

    Southwest operates around 1 flight from Boston to St. Louis every week. The average price of these flights found in the last 72 hours has been $467, but momondo users have found Southwest deals from Boston to St. Louis from as low as $321 round-trip. Southwest has been scored 8.0/10 in 4,247 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 $290, 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 12 flights out of Boston into St. Louis in an average week, so prices vary by time and availability. 11,082 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
O'Fallon
Maryland Heights
Florissant
Fenton
Collinsville
St. Peters
Wentzville
Alton
Farmington
Clayton
Eureka
Festus
Edwardsville
Glencoe
Litchfield
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.
Start using Trips
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