$82 Cheap Flights from St. Louis (STL) to Baltimore (BWI)

View $82 flight on Thu, Sep 18, 2025Opens in a new window

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

  • Plan, book, fly with confidence

  • trending down icon

    Be in the know

    Get alerts if flight prices drop or rise*
  • bex rewards loyalty icon

    Book smarter

    Save up to 30% on select hotels after you book a flight*
  • one key icon

    Earn twice

    Earn your airline miles on top of our OneKeyCash
    Learn about One Key

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

Prices were available within the past 7 days and start at $82 for one-way flights and $163 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Frontier Airlines
Thu, Sep 18 - Mon, Sep 22
STL
St. Louis
BWI
Baltimore
$163 Roundtrip, just found
$163
Roundtrip
just found
Select Frontier Airlines flight, departing Thu, Sep 18 from St. Louis to Baltimore, returning Mon, Sep 22, priced at $163 just found
Frontier Airlines
Thu, Sep 18 - Mon, Sep 22
STL
St. Louis
BWI
Baltimore
$169 Roundtrip, just found
$169
Roundtrip
just found
Select Frontier Airlines flight, departing Thu, Sep 18 from St. Louis to Baltimore, returning Mon, Sep 22, priced at $169 just found
Spirit Airlines
Thu, Nov 6 - Sun, Nov 9
STL
St. Louis
BWI
Baltimore
$174 Roundtrip, just found
$174
Roundtrip
just found
Select Spirit Airlines flight, departing Thu, Nov 6 from St. Louis to Baltimore, returning Sun, Nov 9, priced at $174 just found
Spirit Airlines
Thu, Oct 30 - Sun, Nov 2
STL
St. Louis
BWI
Baltimore
$175 Roundtrip, found 6 hours ago
$175
Roundtrip
found 6 hours ago
Select Spirit Airlines flight, departing Thu, Oct 30 from St. Louis to Baltimore, returning Sun, Nov 2, priced at $175 found 6 hours ago
Spirit Airlines
Tue, Oct 7 - Fri, Oct 10
STL
St. Louis
BWI
Baltimore
$175 Roundtrip, found 19 hours ago
$175
Roundtrip
found 19 hours ago
Select Spirit Airlines flight, departing Tue, Oct 7 from St. Louis to Baltimore, returning Fri, Oct 10, priced at $175 found 19 hours ago
Spirit Airlines
Thu, Sep 18 - Mon, Sep 22
STL
St. Louis
BWI
Baltimore
$181 Roundtrip, just found
$181
Roundtrip
just found
Select Spirit Airlines flight, departing Thu, Sep 18 from St. Louis to Baltimore, returning Mon, Sep 22, priced at $181 just found
Frontier Airlines
Mon, Sep 29 - Thu, Oct 2
STL
St. Louis
BWI
Baltimore
$182 Roundtrip, found 1 hour ago
$182
Roundtrip
found 1 hour ago
Select Frontier Airlines flight, departing Mon, Sep 29 from St. Louis to Baltimore, returning Thu, Oct 2, priced at $182 found 1 hour ago
American Airlines
Thu, Sep 11 - Fri, Sep 12
STL
St. Louis
BWI
Baltimore
$187 Roundtrip, found 3 days ago
$187
Roundtrip
found 3 days ago
Select American Airlines flight, departing Thu, Sep 11 from St. Louis to Baltimore, returning Fri, Sep 12, priced at $187 found 3 days ago
Southwest Airlines
Wed, Oct 15 - Tue, Oct 21
STL
St. Louis
BWI
Baltimore
$189 Roundtrip, found 3 days ago
$189
Roundtrip
found 3 days ago
Select Southwest Airlines flight, departing Wed, Oct 15 from St. Louis to Baltimore, returning Tue, Oct 21, priced at $189 found 3 days ago
United
Wed, Sep 3 - Sat, Sep 6
STL
St. Louis
BWI
Baltimore
$193 Roundtrip, found 4 days ago
$193
Roundtrip
found 4 days ago
Select United flight, departing Wed, Sep 3 from St. Louis to Baltimore, returning Sat, Sep 6, priced at $193 found 4 days ago

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

September is typically the cheapest month to fly

From $124 - $571 per traveler.

Graph displaying average flight prices per month

Alternative airports near Baltimore

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

Select flight to Ronald Reagan Washington National DCA. Average driving time to city center is 57 minutes. Flights from $389
DCA
Ronald Reagan Washington National
Average driving time to city center57 min
Flights from $389
Flights from St. Louis (STL) to Baltimore (BWI)
Origin airport
Lambert-St. Louis Intl.
Destination airport
Baltimore Washington Intl. Thurgood Marshall
Airlines serving
American Airlines, Delta, Frontier Airlines, Southwest Airlines, Spirit Airlines, United
Roundtrip price
$162
Distance
735 mi
Average flight time
4 hours 10 mins

St. Louis to Baltimore Flights

The cheapest times to fly from St. Louis to Baltimore

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 St. Louis to Baltimore are during the month of September. You can find some of the cheapest flights from St. Louis to Baltimore with Expedia's search tool and vast selection of airlines.

 

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

Sunday is one of the best days to book for cheap flights from St. Louis to Baltimore: 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 St. Louis to Baltimore

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 St. Louis to Baltimore in 2025. You can also book with separate airlines for your outbound and return journeys, from $82 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 St. Louis to Baltimore 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 St. Louis to Baltimore 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 Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI) cost?
Grab a cheap one-way flight from $82 or cheap return flight from $163 from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to find our cheapest flight offers on this route.
What is the cheapest month to fly from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI)?
The cheapest month to fly from STL to BWI is September, when demand is low. Off-peak months are usually when you'll find lower airfares between these airports.
Which airlines fly direct from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI)?
You can fly directly from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI) on a Southwest Airlines flight.
What is the cheapest airline that flies from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI)?
Use the filter tool on Expedia to compare different airlines and find the cheapest carrier that'll fly you from STL to BWI. Then, sort your results by "Price (lowest to highest)" to snag a great deal.
How many flights per day from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI)?
With an average of 2 nonstop flights departing from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI) every day, you'll be on your way in no time.
What are the most popular departure times for flights from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI)?
Flights between STL and BWI tend to be busiest at 6 AM. If you're after a more relaxed experience and possibly cheaper prices, look for a time when demand is lower.
What day of the week has the most flights from STL to BWI?
Friday has the most flights from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI). Consider traveling on this day and you'll have a greater chance of finding a schedule that works for you.
What is the earliest flight from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI)?
Lambert-St. Louis Intl. Airport (STL)'s earliest flight to Baltimore Washington Intl. Thurgood Marshall Airport (BWI) leaves at approximately 5:35AM UTC-6. With a total travel time of 2h 5m, you'll touch down at around 8:40AM UTC-5.
How long does it take to fly from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI)?
Flights from STL to BWI have an average travel time of 1 hour and 59 minutes. The distance between these two airports is 740 mi.
What is the best time to fly from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI)?
To avoid possible delays on the Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI) route, aim to fly before 3 PM. Later flights have a 22% higher chance of cancellation.**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 Baltimore from Lambert-St. Louis Intl. Airport (STL)?
Hop on a direct flight from Lambert-St. Louis Intl. Airport (STL) to Baltimore and you'll land at any one of these hubs:

  • Ronald Reagan Washington National Airport (DCA)
  • Washington Dulles Intl. Airport (IAD)
  • Baltimore Washington Intl. Thurgood Marshall Airport (BWI)

Is it cheaper to buy a plane ticket from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI) last-minute?
Booking your ticket from STL to BWI shortly before your trip is generally more expensive. However, if you're flexible with your travel dates and times, you could score a cheap last-minute fare.
Is it cheaper to book a STL to BWI flight and hotel package?
Compared with arranging flights and hotels separately, booking a STL to BWI flight and hotel package with Expedia could lead to significant savings. Better yet, having everything in one convenient place will take the stress out of planning your trip. Just secure your flights and select from our wide range of hotels, then tailor your trip with other add-ons like tours and car rentals.
Can I cancel or change the date of my flight from Lambert-St. Louis Intl. Airport (STL) to Baltimore Washington Intl. Thurgood Marshall Airport (BWI)?
Generally, it's possible to reschedule or cancel your STL to BWI flight. However, if the booking was 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 whether any costs are involved. You'll also find more information on our Customer Service portal.

Explore a world of travel with Expedia

*Available to One Key members.