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$72+ Cheap flights from Baltimore to St. Louis (BWI - 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 10/18. Fares are subject to change and may not be available on all flights or dates of travel.
BWI — STL
Sep 1 — Sep 81
Tue 9/1
Tue 9/8
1 adult, Economy
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Cheapflights Tip: The best prices from Baltimore/Washington to Lambert-St Louis are usually found in October or September, booked 44 days in advance, depart on a Wednesday or Friday and return on a Thursday

Cheap flight deals from Baltimore to St. Louis

Cheapest flights from Baltimore to St. Louis
Explore the most affordable flight options available from Baltimore to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on August 2, 2026.

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.
Mon 9/146:00 am
BWI
-
STL
1 stop8h 10m
Frontier
Mon 9/212:29 pm
STL
-
BWI
1 stop17h 56m
Frontier
Deal found 7/31$141
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.
Tue 10/209:29 pm
BWI
-
STL
1 stop13h 11m
Frontier
Mon 10/2610:35 am
STL
-
BWI
1 stop6h 59m
Frontier
Deal found 7/30$144
This Kiwi.com 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/36:45 am
BWI
-
STL
1 stop11h 37m
Frontier
Mon 9/76:17 pm
STL
-
BWI
1 stop22h 26m
Frontier
Deal found 8/1$146
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.
Thu 8/208:45 am
BWI
-
STL
1 stop9h 37m
Frontier
Mon 8/246:17 pm
STL
-
BWI
1 stop12h 09m
Frontier
Deal found 7/28$147
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 8/278:45 am
BWI
-
STL
1 stop9h 37m
Frontier
Thu 9/36:17 pm
STL
-
BWI
1 stop28h 27m
Frontier
Deal found 7/30$148
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.
Thu 8/278:45 am
BWI
-
STL
1 stop9h 37m
Frontier
Sun 8/306:17 pm
STL
-
BWI
1 stop12h 09m
Frontier
Deal found 7/29$149
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.
Wed 8/199:32 pm
BWI
-
STL
1 stop20h 50m
Frontier
Mon 8/246:17 pm
STL
-
BWI
1 stop12h 09m
Frontier
Deal found 7/30$150
This Kiwi.com 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/48:45 am
BWI
-
STL
1 stop9h 37m
Frontier
Mon 9/76:17 pm
STL
-
BWI
1 stop12h 09m
Frontier
Deal found 8/1$154

Find flight deals from Baltimore to St. Louis

Discover tips and strategies to find the most affordable flight options for your journey from Baltimore (BWI) 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 2, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$141
(Kiwi.com)

One-way from

$72
(Trip.com)

Popular in

June

Cheapest in

October

Average price

$370
Provider with most accurate pricing for Baltimore/Washington-Lambert-St Louis flight deals.
Search Deals
Provider most trusted by Cheapflights users for Baltimore/Washington-Lambert-St Louis flights.
Search Deals
From Baltimore/Washington to Lambert-St Louis
Search Deals
One-way flight from Baltimore/Washington to Lambert-St Louis
Search Deals
Highest demand for flights based on searches. 15% potential increase in price ($73 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($11 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in August 2026
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Baltimore 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 2, 2026.
Use the filters below to find and compare flights from Baltimore to St. Louis that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Thu 9/24

8:30 pm-9:45 pm

Nonstop2h 15m

Lambert-St Louis

Mon 9/28

2:45 pm-7:50 pm

1 stop4h 05m

$292

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Tue 9/29

9:30 am-2:10 pm

1 stop5h 40m

Lambert-St Louis

Wed 9/30

1:20 pm-7:55 pm

1 stop5h 35m

$295

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Thu 9/10

4:25 pm-8:00 pm

1 stop4h 35m

Lambert-St Louis

Mon 9/14

6:05 am-9:10 am

Nonstop2h 05m

$296
Quickest round-trip

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Sat 9/26

9:40 am-10:50 am

Nonstop2h 10m

Lambert-St Louis

Sat 9/26

3:00 pm-6:05 pm

Nonstop2h 05m

$297

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Tue 8/25

1:40 pm-2:50 pm

Nonstop2h 10m

Lambert-St Louis

Tue 9/1

8:10 am-11:15 am

Nonstop2h 05m

$297

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Mon 9/14

6:35 am-7:45 am

Nonstop2h 10m

Lambert-St Louis

Mon 9/21

2:45 pm-7:50 pm

1 stop4h 05m

$301

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Thu 10/15

4:15 pm-7:05 pm

1 stop3h 50m

Lambert-St Louis

Tue 10/20

5:30 am-8:35 am

Nonstop2h 05m

$303

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Fri 8/21

8:30 pm-9:40 pm

Nonstop2h 10m

Lambert-St Louis

Sat 8/22

1:25 pm-6:35 pm

1 stop4h 10m

$312

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Wed 8/19

2:50 pm-8:00 pm

1 stop6h 10m

Lambert-St Louis

Fri 8/21

6:05 am-9:10 am

Nonstop2h 05m

$316

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Tue 9/15

8:00 am-11:20 am

1 stop4h 20m

Lambert-St Louis

Fri 9/18

4:15 pm-7:15 pm

Nonstop2h 00m

$316

Flights are sorted by cheapest round-trip flights first.

Deals found on 8/1

Showing 1-10 of 21 resultsSorted by cheapest first
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3

Compare providers for flights from Baltimore 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 Baltimore to St. Louis in August.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust 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 Baltimore-St. Louis flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Baltimore-St. Louis flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Baltimore-St. Louis flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Baltimore-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 Baltimore-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 Baltimore to St. Louis

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Baltimore 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 Baltimore to St. Louis

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

To ensure you get the cheapest price possible for a flight from Baltimore to St. Louis, you should look to book at least 42 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 Baltimore to St. Louis?

Currently, October is the cheapest month in which you can book a flight from Baltimore to St. Louis (average of $174). Flying from Baltimore to St. Louis in June is currently the most expensive (average of $513). 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 BWI to STL?

Find hourly flight availability from Baltimore 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 2, 2026.

One of the essential ways to save on airfare from Baltimore to St. Louis is to remain as flexible as possible. Flights that are in the evening tend to be the most expensive. A flight at noon could potentially save you up to 14% on airfare.

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

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

Travelers seeking maximum savings on their Baltimore to St. Louis flight should consider departing on Sunday at noon when fares are most often at their lowest. Monday evenings 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 Baltimore to St. Louis?

Airfare is below average for this route at the moment.

Baltimore to St. Louis flights typically cost between $289 and $473 in September.
The cheapest round-trip price found within the last 5 days was $141 on Frontier (Sep 14-Sep 21).

The best insider tips for Baltimore 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 Baltimore to St. Louis trip
Our travel experts
Emily Zemler

Emily Zemler

Expert on BWI

Emily is a freelance writer and book author based in London covering entertainment and travel. Her work has appeared in Los Angeles Times, Observer, and Conde Nast Traveler She has ventured to more than 40 countries and all seven continents, always in search of a great art museum. She has written extensively about hotels, luxury travel, and aviation.

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 2, 2026.
Peruse reviews from past customers who have flown with Southwest,Delta, andAmerican Airlines from Baltimore to St. Louis to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,229 reviews

Boarding

8.1

Comfort

8.0

Food

7.0

Crew

8.6

Overall

8.0

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.
Southwest
8.0
Very good
4,229 reviews
Southwest
8.0
Very good
4,229 reviews

Boarding

8.1

Comfort

8.0

Food

7.0

Crew

8.6

Overall

8.0

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.
Delta
7.8
Good
8,497 reviews
Southwest
8.0
Very good
4,229 reviews

Boarding

8.1

Comfort

8.0

Food

7.0

Crew

8.6

Overall

8.0

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.
American Airlines
7.1
Good
11,845 reviews
Southwest
8.0
Very good
4,229 reviews

Boarding

8.1

Comfort

8.0

Food

7.0

Crew

8.6

Overall

8.0

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.
Frontier
5.6
Fair
2,740 reviews
Southwest
8.0
Very good
4,229 reviews

Boarding

8.1

Comfort

8.0

Food

7.0

Crew

8.6

Overall

8.0

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

Related info for your journey

Find useful and relevant information for your journey from Baltimore 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 Baltimore to St. Louis?

    Lambert-St Louis is the airport most travelers will use when flying to St. Louis from Baltimore/Washington. Booking flights from Baltimore/Washington (BWI) to Lambert-St Louis (STL) should be relatively easy as there are 2 daily flights to St. Louis from 4 different airlines. 2h 10m is how long a flight from Baltimore to Lambert-St Louis will take if you book a nonstop flight.

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

    Flights from Baltimore/Washington to Lambert-St Louis have been viewed 8 times in the past calendar month.

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

    For as low as $292, Southwest can have you in St. Louis from Baltimore in 2h 15m. Airlines will cover a distance of 736 mi. Most flights are nonstop.

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

    Flying on Frontier is currently your cheapest option to St. Louis, with prices starting at $121. Additional round-trip tickets that might be worth considering are offered by Delta and Southwest, with the lowest prices starting at $141 and $270, respectively. Users have found that Frontier is 69% cheaper than the other options available to this destination.

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

    The cheapest airlines for a one-way flight from Baltimore to St. Louis are Frontier ($72), American Airlines ($98), and United Airlines ($117).

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

    Looking for the cheapest flight from Baltimore to St. Louis? While on average our users pay $396, our data indicates the cheapest price to be $144. The most popular route (Baltimore/Washington - Lambert-St Louis), is priced around $182.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Baltimore 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 Baltimore to St. Louis?

    Currently, October is the cheapest month in which you can book a flight from Baltimore to St. Louis (average of $174). Flying from Baltimore to St. Louis in June is currently the most expensive (average of $513). 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 4 airlines flying from Baltimore to St. Louis

Discover the top 4 airlines that operate flights from Baltimore 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 2, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$121Average$173FlexibilityNo cancel feeOn-time62%
DeltaCheapest$141Average$292FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$270Average$444FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$285Average$366FlexibilityNo cancel feeOn-time71%

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