$103 Cheap Flights from Baltimore (BWI) to St. Louis (STL)

View $103 flight on Sat, Oct 25, 2025Opens in a new window

Popular airlines from Baltimore Washington Intl. Airport (BWI) to St. Louis Lambert Intl. Airport (STL)

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Cheap Flights from Baltimore to St. Louis (BWI-STL)

Prices were available within the past 7 days and start at $103 for one-way flights and $172 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frontier Airlines
Sat, Aug 16 - Fri, Aug 22
BWI
Baltimore
STL
St. Louis
$172 Roundtrip, found 10 hours ago
$172
Roundtrip
found 10 hours ago
Select Frontier Airlines flight, departing Sat, Aug 16 from Baltimore to St. Louis, returning Fri, Aug 22, priced at $172 found 10 hours ago
Southwest Airlines
Sat, Sep 13 - Sun, Sep 14
BWI
Baltimore
STL
St. Louis
$176 Roundtrip, found 2 days ago
$176
Roundtrip
found 2 days ago
Select Southwest Airlines flight, departing Sat, Sep 13 from Baltimore to St. Louis, returning Sun, Sep 14, priced at $176 found 2 days ago
Frontier Airlines
Sat, Aug 16 - Fri, Aug 22
BWI
Baltimore
STL
St. Louis
$177 Roundtrip, found 10 hours ago
$177
Roundtrip
found 10 hours ago
Select Frontier Airlines flight, departing Sat, Aug 16 from Baltimore to St. Louis, returning Fri, Aug 22, priced at $177 found 10 hours ago
Frontier Airlines
Sat, Aug 16 - Mon, Aug 18
BWI
Baltimore
STL
St. Louis
$179 Roundtrip, found 10 hours ago
$179
Roundtrip
found 10 hours ago
Select Frontier Airlines flight, departing Sat, Aug 16 from Baltimore to St. Louis, returning Mon, Aug 18, priced at $179 found 10 hours ago
American Airlines
Wed, Oct 1 - Sun, Oct 5
BWI
Baltimore
STL
St. Louis
$180 Roundtrip, found 5 days ago
$180
Roundtrip
found 5 days ago
Select American Airlines flight, departing Wed, Oct 1 from Baltimore to St. Louis, returning Sun, Oct 5, priced at $180 found 5 days ago
United
Sat, Sep 13 - Sun, Sep 14
BWI
Baltimore
STL
St. Louis
$181 Roundtrip, found 2 days ago
$181
Roundtrip
found 2 days ago
Select United flight, departing Sat, Sep 13 from Baltimore to St. Louis, returning Sun, Sep 14, priced at $181 found 2 days ago
Frontier Airlines
Sun, Aug 17 - Sun, Aug 31
BWI
Baltimore
STL
St. Louis
$183 Roundtrip, found 2 days ago
$183
Roundtrip
found 2 days ago
Select Frontier Airlines flight, departing Sun, Aug 17 from Baltimore to St. Louis, returning Sun, Aug 31, priced at $183 found 2 days ago
Southwest Airlines
Wed, Sep 17 - Sun, Sep 21
BWI
Baltimore
STL
St. Louis
$183 Roundtrip, found 1 day ago
$183
Roundtrip
found 1 day ago
Select Southwest Airlines flight, departing Wed, Sep 17 from Baltimore to St. Louis, returning Sun, Sep 21, priced at $183 found 1 day ago
Frontier Airlines
Sat, Aug 16 - Mon, Aug 18
BWI
Baltimore
STL
St. Louis
$184 Roundtrip, found 10 hours ago
$184
Roundtrip
found 10 hours ago
Select Frontier Airlines flight, departing Sat, Aug 16 from Baltimore to St. Louis, returning Mon, Aug 18, priced at $184 found 10 hours ago
Delta
Thu, Aug 21 - Mon, Aug 25
BWI
Baltimore
STL
St. Louis
$201 Roundtrip, found 1 day ago
$201
Roundtrip
found 1 day ago
Select Delta flight, departing Thu, Aug 21 from Baltimore to St. Louis, returning Mon, Aug 25, priced at $201 found 1 day ago

Find the cheapest month to fly from Baltimore (BWI) to St. Louis (STL)

September is typically the cheapest month to fly

From $128 - $455 per traveler.

Graph displaying average flight prices per month

Alternative airports near St. Louis

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to Lambert-St. Louis Intl. STL. Cheapest option available. Average driving time to city center is 20 minutes. Flights from $298
STL
Lambert-St. Louis Intl.
Cheapest
Average driving time to city center20 min
Flights from $298
Flights from Baltimore (BWI) to St. Louis (STL)
Origin airport
Baltimore Washington Intl. Thurgood Marshall
Destination airport
Lambert-St. Louis Intl.
Airlines serving
American Airlines, Delta, Frontier Airlines, Southwest Airlines, Spirit Airlines, United
Roundtrip price
$171
Distance
735 mi
Average flight time
1 hour 12 mins

Baltimore to St. Louis Flights

The cheapest times to fly from Baltimore to St. Louis

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Baltimore to St. Louis are during the month of August. You can find some of the cheapest flights from Baltimore to St. Louis with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Baltimore to St. Louis

Sunday is one of the best days to book for cheap flights from Baltimore to St. Louis: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Baltimore to St. Louis

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Baltimore to St. Louis in 2025. You can also book with separate airlines for your outbound and return journeys, from $103 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Baltimore to St. Louis flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Baltimore to St. Louis airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Frequently asked questions

How much does a flight from Baltimore Washington Intl. Thurgood Marshall Airport (BWI) to Lambert-St. Louis Intl. Airport (STL) cost?
You'll find affordable return tickets from Baltimore Washington Intl. Thurgood Marshall Airport (BWI) to Lambert-St. Louis Intl. Airport (STL) starting from $198. Grab your seat and set off on your next adventure. This information is based on the cheapest price found on Expedia for this return journey departing within the next three months. This airfare is for a Southwest Airlines flight leaving BWI on August 18 2025 and touching down at STL. The price was last updated on July 23 2025 and has not changed since.
What is the cheapest month to fly from BWI to STL?
The cheapest flights from BWI to STL are usually during off-peak season, when demand is lower. To save money, avoid flying during public holidays, school breaks and major local events.
Which airlines fly direct from Baltimore Washington Intl. Thurgood Marshall Airport (BWI) to Lambert-St. Louis Intl. Airport (STL)?
You can fly directly from Baltimore Washington Intl. Thurgood Marshall Airport (BWI) to Lambert-St. Louis Intl. Airport (STL) on a Southwest Airlines flight.
What is the cheapest airline that flies from BWI to STL?
At the moment, the cheapest airline offering one-way flights from BWI to STL is Southwest Airlines. You can take off on this route from $109. This fare is based on the lowest price found on Expedia departing within the next three months. The flight takes off from BWI on October 13 2025. Prices were last updated on July 23 2025 and have not changed since.
How many flights per day from Baltimore Washington Intl. Thurgood Marshall Airport (BWI) to Lambert-St. Louis Intl. Airport (STL)?
With, on average, 2 nonstop flights that operate from Baltimore Washington Intl. Thurgood Marshall Airport (BWI) to Lambert-St. Louis Intl. Airport (STL) every day, you'll be on your way in no time.
What are the most popular departure times for flights from Baltimore Washington Intl. Thurgood Marshall Airport (BWI) to Lambert-St. Louis Intl. Airport (STL)?
Flights between BWI and STL tend to be busiest at 6 AM. If you're after a quieter experience and possibly cheaper fares, choose a time outside the usual busy windows.
What day of the week has the most flights from BWI to STL?
If you fly on a Friday, you'll get the biggest range of options for flights from Baltimore Washington Intl. Thurgood Marshall Airport (BWI) to Lambert-St. Louis Intl. Airport (STL).
What is the earliest flight from Baltimore Washington Intl. Thurgood Marshall Airport (BWI) to Lambert-St. Louis Intl. Airport (STL)?
The first flight of the day out of Baltimore Washington Intl. Thurgood Marshall Airport (BWI) is at around 6:30AM UTC-5. Board this flight and you'll reach Lambert-St. Louis Intl. Airport (STL) at approximately 8:05AM UTC-6. The overall travel time is 2h 35m.
How long does it take to fly from Baltimore Washington Intl. Thurgood Marshall Airport (BWI) to Lambert-St. Louis Intl. Airport (STL)?
Flights from BWI to STL have an average travel time of 2 hours and 29 minutes. The total distance between the two is 740 mi.
What is the best time to fly from Baltimore Washington Intl. Thurgood Marshall Airport (BWI) to Lambert-St. Louis Intl. Airport (STL)?
To avoid potential delays on the Baltimore Washington Intl. Thurgood Marshall Airport (BWI) to Lambert-St. Louis Intl. Airport (STL) route, aim to travel before 3 PM. Departures after this hour have a 22% higher chance of being canceled.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
What airports do you fly into for St. Louis from Baltimore Washington Intl. Thurgood Marshall Airport (BWI)?
Lambert-St. Louis Intl. Airport (STL) is the only airport in St. Louis with direct flights from Baltimore Washington Intl. Thurgood Marshall Airport (BWI). Check out the available options and find affordable fares on Expedia.
Is it cheaper to buy a plane ticket from Baltimore Washington Intl. Thurgood Marshall Airport (BWI) to Lambert-St. Louis Intl. Airport (STL) last-minute?
Waiting until just before your departure to book your flight from BWI to STL generally means paying more. While you may find some last-minute offers, they're not always guaranteed. Keep your travel schedule open to maximize your chances of getting a bargain.
Is it cheaper to book a BWI to STL flight and hotel package?
Compared with arranging hotels and flights separately, booking a BWI to STL flight and hotel package with Expedia could result in significant savings. Better still, having everything in one place will take the hassle out of planning your trip. Simply secure your flights and select from our extensive range of hotels, then personalize your trip with extras like activities and car rentals.
Can I cancel or change the date of my flight from Baltimore Washington Intl. Thurgood Marshall Airport (BWI) to Lambert-St. Louis Intl. Airport (STL)?
Generally, it's possible to cancel or reschedule your BWI to STL flight. However, for bookings made more than 24 hours ago, additional charges may apply. Refer to your airline's policies in your itinerary to see what changes are possible and if any costs are involved. You'll also find more details on our Customer Service portal.

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