Cheap flights from Boston to St. Louis from $71

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 1/21. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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0 bags

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Frontier Logo
11:43 am - 12:09 pmBOS-STL
25h 26m2 stops
Frontier Logo
4:56 pm - 10:48 amSTL-BOS
16h 52m1 stop
$326Frontier
Find Deal
Sat, Nov 1 - Fri, Nov 7
American Airlines Logo
7:00 am - 9:23 amBOS-STL
3h 23mnonstop
American Airlines Logo
9:53 am - 1:32 pmSTL-BOS
2h 39mnonstop
$327American Airlines
Find Deal
Mon, Nov 24 - Thu, Nov 27
Frontier Logo
8:40 am - 9:40 amBOS-STL
26h 00m2 stops
Frontier Logo
11:23 am - 9:00 amSTL-BOS
20h 37m1 stop
$328Frontier
Find Deal
Sun, Nov 2 - Sun, Nov 9
Frontier Logo
6:00 am - 2:29 pmBOS-STL
9h 29m1 stop
Frontier Logo
3:14 pm - 12:44 amSTL-BOS
8h 30m1 stop
$330Frontier
Find Deal
Sun, Nov 23 - Tue, Nov 25
Multiple Airlines Logo
6:16 am - 5:57 pmBOS-STL
12h 41m1 stop
Multiple Airlines Logo
4:13 pm - 8:49 pmSTL-BOS
27h 36m2 stops
$335Multiple Airlines
Find Deal
Thu, Nov 13 - Fri, Nov 21
Spirit Airlines Logo
5:45 am - 1:52 pmBOS-STL
9h 07m1 stop
Spirit Airlines Logo
2:47 pm - 7:06 pmSTL-BOS
27h 19m3 stops
$345Spirit Airlines
Find Deal
Thu, Dec 4 - Sun, Dec 7
Multiple Airlines Logo
9:23 am - 3:38 pmBOS-STL
7h 15m1 stop
Multiple Airlines Logo
7:00 am - 12:20 amSTL-BOS
16h 20m1 stop
$347Multiple Airlines
Find Deal
Sat, Nov 15 - Mon, Nov 17
Southwest Logo
5:15 pm - 7:30 pmBOS-STL
3h 15mnonstop
Southwest Logo
6:10 pm - 9:40 pmSTL-BOS
2h 30mnonstop
$349Southwest
Find Deal
Mon, Dec 8 - Thu, Dec 11
Southwest Logo
7:25 am - 9:40 amBOS-STL
3h 15mnonstop
Southwest Logo
6:10 pm - 9:40 pmSTL-BOS
2h 30mnonstop
$351Southwest
Find Deal
Sat, Nov 15 - Tue, Nov 18
Delta Logo
5:13 pm - 11:42 pmBOS-STL
7h 29m1 stop
Delta Logo
6:05 am - 1:15 pmSTL-BOS
6h 10m1 stop
$369Delta
Find Deal
Mon, Dec 8 - Wed, Dec 10

Southwest flights from Boston to St. Louis

Our best Southwest deals on Boston to St. Louis flight tickets
Southwest
Dec 8
BOS5:15 pmBoston Logan Intl
3h 15m
STL7:30 pmLambert-St Louis
Dec 11
STL6:10 pmLambert-St Louis
2h 30m
BOS9:40 pmBoston Logan Intl
Southwest
Nov 15
BOS7:25 amBoston Logan Intl
3h 15m
STL9:40 amLambert-St Louis
Nov 18
STL6:10 pmLambert-St Louis
2h 30m
BOS9:40 pmBoston Logan Intl
Southwest
Dec 8
BOS6:45 amBoston Logan Intl
7h 35m
1 stop
STL1:20 pmLambert-St Louis
Dec 11
STL6:10 pmLambert-St Louis
2h 30m
BOS9:40 pmBoston Logan Intl

Frontier flights from Boston to St. Louis

Our best Frontier deals on Boston to St. Louis flight tickets
Frontier
Nov 1
BOS11:43 amBoston Logan Intl
25h 26m
2 stops
STL12:09 pmLambert-St Louis
Nov 7
STL4:56 pmLambert-St Louis
16h 52m
1 stop
BOS10:48 amBoston Logan Intl
Frontier
Nov 2
BOS8:40 amBoston Logan Intl
26h 00m
2 stops
STL9:40 amLambert-St Louis
Nov 9
STL11:23 amLambert-St Louis
20h 37m
1 stop
BOS9:00 amBoston Logan Intl
Frontier
Nov 23
BOS6:00 amBoston Logan Intl
9h 29m
1 stop
STL2:29 pmLambert-St Louis
Nov 25
STL3:14 pmLambert-St Louis
8h 30m
1 stop
BOS12:44 amBoston Logan Intl

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 October 27, 2025.
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 11/1

11:43 am-12:09 pm

2 stops25h 26m

Lambert-St Louis

Fri 11/7

4:56 pm-10:48 am

1 stop16h 52m

$326

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Mon 11/24

7:00 am-9:23 am

Nonstop3h 23m

Lambert-St Louis

Thu 11/27

9:53 am-1:32 pm

Nonstop2h 39m

$327

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Sun 11/2

8:40 am-9:40 am

2 stops26h 00m

Lambert-St Louis

Sun 11/9

11:23 am-9:00 am

1 stop20h 37m

$328

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Sun 11/23

6:00 am-2:29 pm

1 stop9h 29m

Lambert-St Louis

Tue 11/25

3:14 pm-12:44 am

1 stop8h 30m

$330

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Thu 11/13

6:16 am-5:57 pm

1 stop12h 41m

Lambert-St Louis

Fri 11/21

4:13 pm-8:49 pm

2 stops27h 36m

$335

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Thu 12/4

5:45 am-1:52 pm

1 stop9h 07m

Lambert-St Louis

Sun 12/7

2:47 pm-7:06 pm

3 stops27h 19m

$345

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Sat 11/15

9:23 am-3:38 pm

1 stop7h 15m

Lambert-St Louis

Mon 11/17

7:00 am-12:20 am

1 stop16h 20m

$347

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Mon 12/8

5:15 pm-7:30 pm

Nonstop3h 15m

Lambert-St Louis

Thu 12/11

6:10 pm-9:40 pm

Nonstop2h 30m

$349

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Sat 11/15

7:25 am-9:40 am

Nonstop3h 15m

Lambert-St Louis

Tue 11/18

6:10 pm-9:40 pm

Nonstop2h 30m

$351

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Mon 12/8

5:13 pm-11:42 pm

1 stop7h 29m

Lambert-St Louis

Wed 12/10

6:05 am-1:15 pm

1 stop6h 10m

$369

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 $393.

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 $500. 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 $430 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 $457 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 $445 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 $391 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 15% 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 October 2025, prices for Boston to St. Louis flights are approximately 13% cheaper 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

3h 05m

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 $360.
The fastest flight from Boston to St. Louis takes 3h 05m
Direct flights go from Boston to St. Louis every day.
There is 1 airport near St. Louis: Lambert-St Louis (STL)
  • 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 3h 15m, 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 $83Free CancellationRating
6.3
8,112 reviews
Search Spirit Airlines flights
FrontierPriceFrom $110Free CancellationRating
5.8
3,123 reviews
Search Frontier flights
DeltaPriceFrom $216Free CancellationRating
7.9
7,996 reviews
Search Delta flights
United AirlinesPriceFrom $261Free CancellationRating
7.4
8,999 reviews
Search United Airlines flights
American AirlinesPriceFrom $297Free CancellationRating
7.2
11,031 reviews
Search American Airlines flights
SouthwestPriceFrom $320Free CancellationRating
8.0
4,238 reviews
Search Southwest flights
  • Southwest Flights From Boston to St. Louis

    Southwest operates around 15 flights from Boston to St. Louis every week. The average price of these flights found in the last 72 hours has been $466, but momondo users have found Southwest deals from Boston to St. Louis from as low as $320 round-trip. Southwest has been scored 8.0/10 in 4,238 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 $297, round-trip. It should be noted that an average American Airlines flight deal for this route in this time was higher, at $456 round-trip. American Airlines operates 9 flights out of Boston into St. Louis in an average week, so prices vary by time and availability. 11,031 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
Wentzville
Collinsville
Fenton
St. Peters
Alton
Farmington
Festus
Glencoe
Edwardsville
Clayton
Eureka
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.

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1 adult
Wed 11/26
Wed 12/3

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