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St. Louis

$91+ Cheap flights from Boston to St. Louis (BOS - STL)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 8/23. Fares are subject to change and may not be available on all flights or dates of travel.
BOS — STL
Aug 31 — Sep 71
Mon 8/31
Mon 9/7
1 adult, Economy
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Find cheap flights from Boston to St. Louis with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

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Cheapflights Tip: The best prices from Boston Logan Intl to Lambert-St Louis are usually found in January or August, booked 75 days in advance, depart on a Wednesday or Thursday and return on a Wednesday

Cheap flight deals from Boston to St. Louis

Cheapest flights from Boston to St. Louis
Explore the most affordable flight options available from Boston to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on August 1, 2026.

This Kiwi.com deal was found by Cheapflights users on 7/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/1510:04 am
BOS
-
STL
1 stop14h 55m
Frontier
Mon 8/246:17 pm
STL
-
BOS
1 stop16h 30m
Frontier
Deal found 7/28$328
This American Airlines deal was found by Cheapflights users on 7/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/15:45 pm
BOS
-
STL
1 stop7h 29m
American Airlines
Wed 9/305:00 am
STL
-
BOS
1 stop8h 08m
American Airlines
Deal found 7/28$330
This Kiwi.com deal was found by Cheapflights users on 7/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/2910:04 am
BOS
-
STL
1 stop7h 07m
Frontier
Tue 9/15:27 pm
STL
-
BOS
2 stops38h 42m
Frontier
Deal found 7/28$331
This Southwest deal was found by Cheapflights users on 7/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/305:35 am
BOS
-
STL
Nonstop2h 50m
Southwest
Thu 10/14:30 pm
STL
-
BOS
2 stops6h 35m
Southwest
Deal found 7/28$332
This Kiwi.com deal was found by Cheapflights users on 7/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/310:04 am
BOS
-
STL
1 stop7h 07m
Frontier
Sun 9/66:17 pm
STL
-
BOS
2 stops16h 33m
Frontier
Deal found 7/30$334
This Kiwi.com deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/289:36 am
BOS
-
STL
1 stop8h 46m
Frontier
Fri 9/46:17 pm
STL
-
BOS
1 stop16h 30m
Frontier
Deal found 7/31$336
This Delta deal was found by Cheapflights users on 7/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/205:30 am
BOS
-
STL
1 stop5h 24m
Delta
Wed 8/262:10 pm
STL
-
BOS
1 stop4h 48m
Delta
Deal found 7/28$337
This Southwest deal was found by Cheapflights users on 7/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/125:35 am
BOS
-
STL
Nonstop2h 50m
Southwest
Wed 8/191:20 pm
STL
-
BOS
Nonstop2h 35m
Southwest
Deal found 7/29$338
This Southwest deal was found by Cheapflights users on 8/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/55:50 am
BOS
-
STL
2 stops8h 35m
Southwest
Sun 9/66:45 am
STL
-
BOS
1 stop4h 30m
Southwest
Deal found 8/1$342
This American Airlines deal was found by Cheapflights users on 7/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/236:20 am
BOS
-
STL
Nonstop3h 00m
American Airlines
Wed 9/236:00 pm
STL
-
BOS
Nonstop2h 47m
American Airlines
Deal found 7/30$343
This Kiwi.com deal was found by Cheapflights users on 7/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/49:36 am
BOS
-
STL
1 stop8h 46m
Frontier
Sun 9/66:17 pm
STL
-
BOS
1 stop16h 30m
Frontier
Deal found 7/29$344
This Kiwi.com deal was found by Cheapflights users on 7/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/219:36 am
BOS
-
STL
1 stop8h 46m
Frontier
Mon 8/246:17 pm
STL
-
BOS
1 stop16h 30m
Frontier
Deal found 7/31$345

Find flight deals from Boston to St. Louis

Discover tips and strategies to find the most affordable flight options for your journey from Boston (BOS) to St. Louis (STL). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated August 1, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$328
(Kiwi.com)

One-way from

$91
(Kiwi.com)

Popular in

July

Cheapest in

January

Average price

$431

Good round-trip deal

$372 or less

Good one-way deal

$258 or less
Provider with most accurate pricing for Boston Logan Intl-Lambert-St Louis flight deals.
Search Deals
Provider most trusted by Cheapflights users for Boston Logan Intl-Lambert-St Louis flights.
Search Deals
From Boston Logan Intl to Lambert-St Louis
Search Deals
One-way flight from Boston Logan Intl to Lambert-St Louis
Search Deals
Highest demand for flights based on searches. 4% potential increase in price ($22 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($8 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in August 2026
Search Deals
Price to beat on a round-trip flight from Boston Logan Intl to Lambert-St Louis.
Search Deals
Price to beat on a one-way flight from Boston Logan Intl to Lambert-St Louis.
Search Deals

Cheapflights 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, Cheapflights users made 2,558,603 searches. Data last updated August 1, 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

Cheapest round-trip

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Thu 9/10

12:40 pm-7:10 pm

2 stops7h 30m

Lambert-St Louis

Mon 9/14

4:15 pm-10:15 pm

1 stop5h 00m

$342

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Wed 9/30

10:50 am-5:55 pm

2 stops8h 05m

Lambert-St Louis

Thu 10/1

5:50 pm-11:50 pm

1 stop5h 00m

$342

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Thu 10/1

10:40 am-6:05 pm

2 stops8h 25m

Lambert-St Louis

Sat 10/3

10:05 am-6:20 pm

2 stops7h 15m

$347

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Thu 8/20

7:40 am-3:10 pm

2 stops8h 30m

Lambert-St Louis

Mon 8/24

2:45 pm-10:10 pm

2 stops6h 25m

$368

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Wed 9/16

5:25 am-11:20 am

2 stops6h 55m

Lambert-St Louis

Thu 9/17

4:15 pm-10:15 pm

1 stop5h 00m

$368
Quickest round-trip

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Thu 10/8

5:25 am-7:25 am

Nonstop3h 00m

Lambert-St Louis

Mon 10/19

5:55 am-9:30 am

Nonstop2h 35m

$369

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Fri 9/4

9:00 am-3:38 pm

1 stop7h 38m

Lambert-St Louis

Mon 9/7

5:23 pm-1:25 am

1 stop7h 02m

$370

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Fri 9/4

12:40 pm-7:10 pm

2 stops7h 30m

Lambert-St Louis

Sun 9/6

6:45 am-12:15 pm

1 stop4h 30m

$375

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Tue 9/15

3:20 pm-9:45 pm

1 stop7h 25m

Lambert-St Louis

Tue 9/22

6:30 am-2:40 pm

2 stops7h 10m

$394

BostonSt. Louis

BOS - STL

BOSSTL

Boston Logan Intl

Sat 9/19

8:10 am-1:25 pm

2 stops6h 15m

Lambert-St Louis

Sat 9/26

1:40 pm-9:45 pm

2 stops7h 05m

$399

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/27

Showing 1-10 of 20 resultsSorted by cheapest first
1
2

Compare providers for flights from Boston to St. Louis

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Boston to St. Louis in August.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
JustAirTicketPrice Accuracy-Trust Score*1 star
PricelinePrice Accuracy1 starTrust Score*3 stars
CheapTicketsDealPrice Accuracy1 starTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Boston-St. Louis flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Boston-St. Louis flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Boston-St. Louis flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Boston-St. Louis flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Boston-St. Louis flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Boston to St. Louis

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Boston with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Boston to St. Louis

How far ahead should I book a flight from Boston to St. Louis?

To ensure you get the cheapest price possible for a flight from Boston to St. Louis, you should look to book at least 74 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

What is the cheapest month to book a flight from Boston to St. Louis?

Currently, January is the cheapest month in which you can book a flight from Boston to St. Louis (average of $408). Flying from Boston to St. Louis in July is currently the most expensive (average of $571). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from BOS to STL?

Find hourly flight availability from Boston to St. Louis. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated August 1, 2026.

It’s typically best to fly out from Boston to St. Louis in the evening. Doing so could potentially save you 11% on the flight price compared to flying in the afternoon, which is usually more expensive.

What is the cheapest day to fly from Boston to St. Louis?

Use this chart to determine the cheapest time to fly round-trip from Boston to St. Louis. Price data was last updated on July 25, 2026.

Travelers seeking maximum savings on their Boston to St. Louis flight should consider departing on Wednesday at noon when fares are most often at their lowest. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.

How much does it cost to fly round-trip from Boston to St. Louis?

Airfare is typical for this route at the moment.

Boston to St. Louis flights typically cost between $321 and $567 in August.
The cheapest round-trip price found within the last 5 days was $328 on Frontier (Aug 15-Aug 24).

The best insider tips for Boston to St. Louis flights

AI-powered summary based on content written by travel experts. AI can make mistakes.
Cheapflights partnered with top experts to bring you the best recommendations for your Boston to St. Louis trip
Our travel experts
Paul Rubio

Paul Rubio

Expert on BOS

Travel journalist and photographer Paul Rubio is a Miami native (and current resident), who has lived in nine countries and traveled to 137. He is an expert in luxury travel, eco-travel, loyalty programs, hotels, airports and airlines. He is a contributing editor at AFAR, Condé Nast Traveler, LUXURY Magazine, and Palm Beach Illustrated.

Read more
Taryn White

Taryn White

Expert on STL

Taryn White is a freelance travel writer, digital creator, and travel advisor who has visited nearly 100 countries and all 50 states. She’s familiar with many airports and enjoys beach hopping, boutique hotels, spa experiences, and exploring local culture. Her work has appeared in Travel + Leisure, Condé Nast Traveler, National Geographic, Smithsonian Magazine, AFAR, and more.

Read more

Reviews of airlines servicing St. Louis

Get insights into the airlines that provide service to St. Louis. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to St. Louis. Reviews last updated August 1, 2026.
Read through reviews of airlines operating flights from Boston to St. Louis, such as Southwest,Delta, andAmerican Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,229 reviews

Food

7.0

Overall

8.0

Boarding

8.1

Crew

8.6

Entertainment

7.5

Comfort

8.0

Reviews

1 / 20
8.0
Excellent

Libby,Jun 2026

TUS - LAS

One delay in a 2 layover flight=a good trip. The crew was great.
Southwest
8.0
Very good
4,229 reviews
Southwest
8.0
Very good
4,229 reviews

Food

7.0

Overall

8.0

Boarding

8.1

Crew

8.6

Entertainment

7.5

Comfort

8.0

Reviews

1 / 20
8.0
Excellent

Libby,Jun 2026

TUS - LAS

One delay in a 2 layover flight=a good trip. The crew was great.
Delta
7.8
Good
8,497 reviews
Southwest
8.0
Very good
4,229 reviews

Food

7.0

Overall

8.0

Boarding

8.1

Crew

8.6

Entertainment

7.5

Comfort

8.0

Reviews

1 / 20
8.0
Excellent

Libby,Jun 2026

TUS - LAS

One delay in a 2 layover flight=a good trip. The crew was great.
American Airlines
7.1
Good
11,845 reviews
Southwest
8.0
Very good
4,229 reviews

Food

7.0

Overall

8.0

Boarding

8.1

Crew

8.6

Entertainment

7.5

Comfort

8.0

Reviews

1 / 20
8.0
Excellent

Libby,Jun 2026

TUS - LAS

One delay in a 2 layover flight=a good trip. The crew was great.
JetBlue
7.1
Good
3,030 reviews
Southwest
8.0
Very good
4,229 reviews

Food

7.0

Overall

8.0

Boarding

8.1

Crew

8.6

Entertainment

7.5

Comfort

8.0

Reviews

1 / 20
8.0
Excellent

Libby,Jun 2026

TUS - LAS

One delay in a 2 layover flight=a good trip. The crew was great.
Frontier
5.6
Fair
2,740 reviews
Southwest
8.0
Very good
4,229 reviews

Food

7.0

Overall

8.0

Boarding

8.1

Crew

8.6

Entertainment

7.5

Comfort

8.0

Reviews

1 / 20
8.0
Excellent

Libby,Jun 2026

TUS - LAS

One delay in a 2 layover flight=a good trip. The crew was great.

Related info for your journey

Find useful and relevant information for your journey from Boston to St. Louis. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airports do I use to fly from Boston to St. Louis?

    If you wish to fly to St. Louis from Boston, then you need to book flights from Boston Logan Intl to Lambert-St Louis. There are 2 flights from Logan Intl (BOS) to Lambert-St Louis (STL) per day to choose from. Flights to St. Louis from Logan Intl are available from 5 different airlines, which means you should have some options if you want to compare airfare deals. 2h 50m is how long a nonstop flight from Boston to Lambert-St Louis typically takes.

  • How popular is this Boston to St. Louis flight route?

    Flights from Boston Logan Intl to Lambert-St Louis have been viewed 31 times in the past calendar month.

  • How long is the flight from Boston to St. Louis?

    Airlines like Southwest fly from Boston to St. Louis in about 7h 30m. The time it takes to get you to your destination can typically vary by up to . The distance between Boston and St. Louis is about 1043 mi.

  • What are the cheapest airlines flying from Boston to St. Louis round-trip?

    Cheapflights users have booked flights from Boston to St. Louis round-trip from $90. Other airlines that can offer you cheap pricing are Delta, from $148, and American Airlines, from $298. Frontier is priced at 81% lower than the current average price of a flight leaving 3 months from now.

  • What are the cheapest airlines to fly from Boston to St. Louis one-way?

    The cheapest airline one-way is Frontier, with whom users have recently found tickets for as low as $67. However, be on the lookout for offers from Southwest and United Airlines, as they are both options that can get you from Boston to St. Louis for a low price.

  • What are the most reliable airlines from Boston to St. Louis?

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Boston to St. Louis on time: Iberia (81%), Envoy Air (75%), American Airlines (72%).

  • What are the cheapest flights from Boston to St. Louis?

    Looking at all options, your cheapest flight can be booked for $149. While the most popular route (Boston Logan Intl - Lambert-St Louis) can be booked for $293 on average, our data indicates $383 when flying from Boston to St. Louis.

  • Can I find deals for flights from Boston to St. Louis that include hotel bookings?

    Yes. In addition to deals on Boston to St. Louis flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Boston to St. Louis?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Boston to St. Louis.

  • Can I find deals for business class flights from Boston to St. Louis?

    Yes. Cheapflights offers flight deals from Boston to St. Louis by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Boston to St. Louis?

    Currently, January is the cheapest month in which you can book a flight from Boston to St. Louis (average of $408). Flying from Boston to St. Louis in July is currently the most expensive (average of $571). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
Edwardsville
O'Fallon
Fenton
Swansea
Fairview Heights
Eureka
Maryland Heights
Collinsville
Wentzville
Glencoe
Chesterfield
Farmington

Browse thousands of different options on Cheapflights for your next trip

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Top 5 airlines flying from Boston to St. Louis

Discover the top 5 airlines that operate flights from Boston to St. Louis. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated August 1, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$90Average$255FlexibilityNo cancel feeOn-time62%
DeltaCheapest$148Average$555FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$301Average$510FlexibilityNo cancel feeOn-time71%
JetBlueCheapest$327Average$437FlexibilityNo cancel feeOn-time62%
SouthwestCheapest$335Average$507FlexibilityNo cancel feeOn-time63%

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