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Cheap flights from St. Louis to Boston from $85

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from St. Louis to Boston departing on 9/4. 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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Find the cheapest flights from St. Louis to Boston

Cheap round-trip flights

Logo
4:00 pm - 9:58 amSTL-BOS
16h 58m1 stop
Logo
3:00 pm - 9:40 amBOS-STL
19h 40m1 stop
$207
Find Deal
Thu, Sep 4 - Sat, Sep 13
Spirit Airlines Logo
10:54 am - 11:55 pmSTL-BOS
12h 01m1 stop
Spirit Airlines Logo
6:10 am - 5:55 pmBOS-STL
12h 45m1 stop
$212Spirit Airlines
Find Deal
Thu, Oct 30 - Sat, Nov 1
American Airlines Logo
7:23 am - 6:48 pmSTL-BOS
10h 25m1 stop
American Airlines Logo
12:52 pm - 9:53 pmBOS-STL
10h 01m1 stop
$217American Airlines
Find Deal
Sat, Sep 6 - Sat, Sep 13
Spirit Airlines Logo
10:57 am - 11:59 pmSTL-BOS
12h 02m1 stop
Spirit Airlines Logo
6:11 am - 5:45 pmBOS-STL
12h 34m1 stop
$219Spirit Airlines
Find Deal
Tue, Oct 21 - Sat, Oct 25
American Airlines Logo
6:00 am - 2:49 pmSTL-BOS
7h 49m1 stop
American Airlines Logo
4:10 pm - 6:15 pmBOS-STL
3h 05mnonstop
$222American Airlines
Find Deal
Mon, Sep 22 - Mon, Sep 22
Delta Logo
6:00 am - 1:20 pmSTL-BOS
6h 20m1 stop
Delta Logo
10:00 am - 3:25 pmBOS-STL
6h 25m1 stop
$251Delta
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Tue, Sep 9 - Tue, Sep 16
Frontier Logo
11:02 am - 9:15 amSTL-BOS
21h 13m1 stop
Frontier Logo
9:18 am - 1:27 pmBOS-STL
29h 09m1 stop
$268Frontier
Find Deal
Thu, Oct 30 - Sun, Nov 2
Delta Logo
5:11 pm - 1:18 amSTL-BOS
7h 07m1 stop
Delta Logo
1:36 pm - 7:05 pmBOS-STL
6h 29m1 stop
$269Delta
Find Deal
Mon, Sep 15 - Tue, Sep 23
Southwest Logo
11:10 am - 7:10 pmSTL-BOS
7h 00m2 stops
Southwest Logo
9:05 am - 3:45 pmBOS-STL
7h 40m1 stop
$282Southwest
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Tue, Sep 9 - Tue, Sep 16
Southwest Logo
11:10 am - 7:10 pmSTL-BOS
7h 00m2 stops
Southwest Logo
9:25 am - 8:05 pmBOS-STL
11h 40m2 stops
$292Southwest
Find Deal
Tue, Sep 9 - Tue, Sep 16

American Airlines flights from St. Louis to Boston

Our best American Airlines deals on St. Louis to Boston flight tickets
American Airlines
Sep 6
STL7:23 amLambert-St Louis
10h 25m
1 stop
BOS6:48 pmBoston Logan Intl
Sep 13
BOS12:52 pmBoston Logan Intl
10h 01m
1 stop
STL9:53 pmLambert-St Louis
$217
Find similar
American Airlines
Sep 22
STL6:00 amLambert-St Louis
7h 49m
1 stop
BOS2:49 pmBoston Logan Intl
Sep 22
BOS4:10 pmBoston Logan Intl
3h 05m
STL6:15 pmLambert-St Louis
$222
Find similar
American Airlines
Sep 9
STL9:56 amLambert-St Louis
7h 49m
1 stop
BOS6:45 pmBoston Logan Intl
Sep 16
BOS7:00 amBoston Logan Intl
3h 12m
STL9:12 amLambert-St Louis
$237
Find similar

Spirit Airlines flights from St. Louis to Boston

Our best Spirit Airlines deals on St. Louis to Boston flight tickets
Spirit Airlines
Oct 30
STL10:54 amLambert-St Louis
12h 01m
1 stop
BOS11:55 pmBoston Logan Intl
Nov 1
BOS6:10 amBoston Logan Intl
12h 45m
1 stop
STL5:55 pmLambert-St Louis
$212
Find similar
Spirit Airlines
Oct 21
STL10:57 amLambert-St Louis
12h 02m
1 stop
BOS11:59 pmBoston Logan Intl
Oct 25
BOS6:11 amBoston Logan Intl
12h 34m
1 stop
STL5:45 pmLambert-St Louis
$219
Find similar
Spirit Airlines
Oct 11
STL7:00 pmLambert-St Louis
15h 26m
1 stop
BOS11:26 amBoston Logan Intl
Oct 18
BOS6:10 amBoston Logan Intl
12h 45m
1 stop
STL5:55 pmLambert-St Louis
$230
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from St. Louis to Boston 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 August 14, 2025.
Use the filters below to find and compare flights from St. Louis to Boston that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

St. LouisBoston

STL - BOS

STLBOS

Lambert-St Louis

Thu 9/4

4:00 pm-9:58 am

1 stop16h 58m

Boston Logan Intl

Sat 9/13

3:00 pm-9:40 am

1 stop19h 40m

$207

St. LouisBoston

STL - BOS

STLBOS

Lambert-St Louis

Thu 10/30

10:54 am-11:55 pm

1 stop12h 01m

Boston Logan Intl

Sat 11/1

6:10 am-5:55 pm

1 stop12h 45m

$212

St. LouisBoston

STL - BOS

STLBOS

Lambert-St Louis

Sat 9/6

7:23 am-6:48 pm

1 stop10h 25m

Boston Logan Intl

Sat 9/13

12:52 pm-9:53 pm

1 stop10h 01m

$217

St. LouisBoston

STL - BOS

STLBOS

Lambert-St Louis

Tue 10/21

10:57 am-11:59 pm

1 stop12h 02m

Boston Logan Intl

Sat 10/25

6:11 am-5:45 pm

1 stop12h 34m

$219

St. LouisBoston

STL - BOS

STLBOS

Lambert-St Louis

Mon 9/22

6:00 am-2:49 pm

1 stop7h 49m

Boston Logan Intl

Mon 9/22

4:10 pm-6:15 pm

Nonstop3h 05m

$222

St. LouisBoston

STL - BOS

STLBOS

Lambert-St Louis

Tue 9/9

6:00 am-1:20 pm

1 stop6h 20m

Boston Logan Intl

Tue 9/16

10:00 am-3:25 pm

1 stop6h 25m

$251

St. LouisBoston

STL - BOS

STLBOS

Lambert-St Louis

Thu 10/30

11:02 am-9:15 am

1 stop21h 13m

Boston Logan Intl

Sun 11/2

9:18 am-1:27 pm

1 stop29h 09m

$268

St. LouisBoston

STL - BOS

STLBOS

Lambert-St Louis

Mon 9/15

5:11 pm-1:18 am

1 stop7h 07m

Boston Logan Intl

Tue 9/23

1:36 pm-7:05 pm

1 stop6h 29m

$269

St. LouisBoston

STL - BOS

STLBOS

Lambert-St Louis

Tue 9/9

11:10 am-7:10 pm

2 stops7h 00m

Boston Logan Intl

Tue 9/16

9:05 am-3:45 pm

1 stop7h 40m

$282

St. LouisBoston

STL - BOS

STLBOS

Lambert-St Louis

Tue 9/9

11:10 am-7:10 pm

2 stops7h 00m

Boston Logan Intl

Tue 9/16

9:25 am-8:05 pm

2 stops11h 40m

$292

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 Boston from

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

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 Boston?

In general, September is the cheapest month to fly from St. Louis to Boston. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $377. If you aren’t able to travel during the month of September, then book flights to Boston from St. Louis during August instead. Flights to Boston in August, while not as cheap as those in September, still average around $386.

What is the cheapest day to depart on your flight to Boston?

The cheapest day to depart from St. Louis to Boston is on a Thursday when prices can be found for as low as $496. Be sure to avoid booking your departure on a Saturday as prices are generally higher than usual. According to our data, the average ticket price to Boston on Saturday is $822.

What is the cheapest time of day to depart on your flight to Boston?

According to our data, the cheapest time of day to fly to Boston is in the afternoon. momondo users have found flights departing from St. Louis to Boston in the afternoon for as low as $421. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. At noon is when there is more demand to fly to Boston, so prices are often more expensive at around $1,064 per ticket.

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

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

How far in advance should I book a flight to Boston?

You are more likely to see cheaper flights to Boston from St. Louis when booking weeks ahead of your departure date. In general, you can expect to find flights to Boston for around $423 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Boston from St. Louis for as low as $346 on momondo.

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

There are 4 cabin classes available to choose from on Lambert-St Louis to Boston Logan Intl 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 St. Louis to Boston flights?

You could potentially save up to 25% on your flight if you consider stops on a St. Louis to Boston flight.

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

As of August 2025, prices for St. Louis to Boston flights are approximately 36% cheaper when compared to flights at the same time last year.

When to book flights from St. Louis to Boston

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

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

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

Best Price Found

$85

Fastest flight time

2h 30m

Direct flights

Every day

Airports in Boston

1 airport
The best one-way flight to Boston from St. Louis in the past 72 hours is $85. The best round-trip flight deal from St. Louis to Boston found on momondo in the last 72 hours is $207.
The fastest flight from St. Louis to Boston takes 2h 30m
Direct flights go from St. Louis to Boston every day.
There is 1 airport near Boston: Boston Logan Intl (BOS)
Search flight deals

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

    Boston Logan Intl is 1035.0 mi away from Lambert-St Louis. By plane, this route typically takes 2h 35m.

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

    Prices for flights from Lambert-St Louis Airport to Boston Logan Intl Airport are refreshed on a daily basis.

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

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

    The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Lambert-St Louis Airport to Boston Logan Intl Airport.

  • What documentation or ID do you need to fly to Boston Logan Intl Airport?

    The travel and health documents required for your trip to Boston Logan Intl Airport can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Boston Logan Intl Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

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

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

Best airlines flying from St. Louis to Boston

Compare and see reviews for airlines that fly from St. Louis to Boston with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $75Free CancellationRating
5.8
3,219 reviews
Search Frontier flights
Spirit AirlinesPriceFrom $147Free CancellationRating
6.3
8,045 reviews
Search Spirit Airlines flights
United AirlinesPriceFrom $153Free CancellationRating
7.4
8,916 reviews
Search United Airlines flights
DeltaPriceFrom $206Free CancellationRating
8.0
7,980 reviews
Search Delta flights
American AirlinesPriceFrom $263Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights
SouthwestPriceFrom $303Free CancellationRating
8.0
4,244 reviews
Search Southwest flights

  • Southwest Flights From St. Louis to Boston

    The lowest priced Southwest flight from St. Louis to Boston from the last 72 hours was $303. Generally, Southwest has 15 flights on this route every week with an average price of $448. Southwest is rated 8.0/10 by our users.

  • American Airlines Flights From St. Louis to Boston

    The best American Airlines deal for St. Louis to Boston flight tickets found on momondo in the last 72 hours was $263, round-trip. It should be noted that an average American Airlines flight deal for this route in this time was higher, at $428 round-trip. American Airlines operates 12 flights out of St. Louis into Boston in an average week, so prices vary by time and availability. 10,000 American Airlines reviews by users on momondo have scored the airline at 7.2/10.

Traveling to a place near Boston?

Book flights to Boston if you plan to visit one of these locations
Hampton Beach
Salem
Ogunquit
Hampton
Old Orchard Beach
York Beach
Plymouth
Kennebunkport
Nashua
Cambridge
Narragansett
Laconia
South Yarmouth
Brockton
Gloucester
Concord
Everett
Falmouth
Wells
Sturbridge

Why use momondo?

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

momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from St. Louis to Boston. Millions of users trust and use momondo every year so you are in good hands.

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

Yes. momondo enables you to select and highlight flights to Boston from St. Louis with this policy.

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

Once you have performed a search in the form on the page, momondo provides useful filters and insights. We can show you the cheapest days and times to fly as well as help filter your options to help you make an informed choice when booking flights to Boston from St. Louis.

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

Price alerts on flights to Boston from St. Louis are quick and easy to set up on momondo. Simply perform a search and select the price alert feature. It is as simple as that.

An easier way to manage your Boston 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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