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Cheap Flights from St Louis to Baltimore Washington International

Compare St Louis to Baltimore Washington International flight deals

Find the cheapest month or even day of the year to fly to Baltimore Washington International

Book the best Baltimore Washington International fare with no extra fees

Flight deals from St Louis to Baltimore Washington International

Looking for a cheap last-minute deal or the best return flight from St Louis to Baltimore Washington International? Find the lowest prices on one-way and return tickets right here.
Washington D.C..R 1,039 per passenger.Departing Wed, 18 Mar.One-way flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from St Louis on Wed, 18 Mar, arriving in Baltimore Washington International.Price includes taxes and charges.From R 1,039, select.
Washington D.C..R 1,130 per passenger.Departing Wed, 6 May.One-way flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from St Louis on Wed, 6 May, arriving in Baltimore Washington International.Price includes taxes and charges.From R 1,130, select.
Washington D.C..R 1,135 per passenger.Departing Wed, 15 Apr.One-way flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from St Louis on Wed, 15 Apr, arriving in Baltimore Washington International.Price includes taxes and charges.From R 1,135, select.
Washington D.C..R 2,182 per passenger.Departing Tue, 7 Apr.One-way flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from St Louis on Tue, 7 Apr, arriving in Baltimore Washington International.Price includes taxes and charges.From R 2,182, select.
Washington D.C..R 2,430 per passenger.Departing Tue, 4 Aug.One-way flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from St Louis on Tue, 4 Aug, arriving in Baltimore Washington International.Price includes taxes and charges.From R 2,430, select.
Washington D.C..R 2,629 per passenger.Departing Wed, 6 May.One-way flight with Southwest Airlines.Outbound direct flight with Southwest Airlines departs from St Louis on Wed, 6 May, arriving in Baltimore Washington International.Price includes taxes and charges.From R 2,629, select.
Washington D.C..R 2,707 per passenger.Departing Tue, 28 Jul.One-way flight with Frontier Airlines.Outbound indirect flight with Frontier Airlines, departs from St Louis on Tue, 28 Jul, arriving in Baltimore Washington International.Price includes taxes and charges.From R 2,707, select.
Washington D.C..R 2,729 per passenger.Departing Wed, 17 Jun.One-way flight with Southwest Airlines.Outbound indirect flight with Southwest Airlines, departs from St Louis on Wed, 17 Jun, arriving in Baltimore Washington International.Price includes taxes and charges.From R 2,729, select.

Find the cheapest month to fly from St Louis to Baltimore Washington International

We’re always keeping an eye on fares, so you can find the best one in seconds. It looks like St Louis to Baltimore Washington International flights are currently cheapest in March.
Feb
from R 2,796
Mar
from R 1,039
Apr
from R 1,135
May
from R 1,130
Jun
from R 2,729
Jul
from R 2,707
Aug
from R 2,430
Sep
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Oct
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Nov
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Dec
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Jan
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Direct flights from St Louis to Baltimore Washington International

St Louis to Baltimore Washington International: Alternative routes

Compare routes from St Louis to Washington D.C. below. You may find an airport to fly into that's cheaper, faster, or easier than Baltimore Washington International.

Washington Ronald Reagan

5km from central Washington D.C.
Closest
from R 1,366
Search flights

Camp Springs Andrews AFB

17km from central Washington D.C.
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Washington Dulles

37km from central Washington D.C.
Cheapest
from R 1,039
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Baltimore Washington International

44km from central Washington D.C.
Cheapest
from R 1,039
Search flights

Manassas

47km from central Washington D.C.
Search flights

St Louis to Washington D.C.: Flight information

The things to know before you go.
Cheapest flight foundR 1,039
Cheapest month to flyMarch
Average flight time2 hrs, 2 mins
Most popular airlineSouthwest Airlines
Average flights per week31

Finding cheap flights from St Louis to Baltimore Washington International: Frequently asked questions

The best price we found for a return flight from St Louis to Baltimore Washington International is R 2,430. This is an estimate based on information collected from different airlines and travel providers over the last 4 days and is subject to change and availability.
2 hours and 2 minutes is the average flight time from St Louis to Baltimore Washington International.
Southwest Airlines flies direct from St Louis to Baltimore Washington International.
As of February 2026, there are 31 flights per week flying from St Louis to Baltimore Washington International.
The cheapest month to fly from St Louis to Baltimore Washington International is usually April.
After crunching the numbers on our flight calendar, we found that it's currently cheapest to fly from St Louis Airport to Baltimore Washington International Airport on Tuesday, 7 April 2026.
Yes – the average flight time is 2 hours and 2 minutes.
We show every price from over 1,200 airlines and travel agents, comparing them all so you don’t have to. If you know you want to fly to Baltimore Washington International but you’re not ready to book, set up a Price Alert. We’ll track prices for you, and let you know when they rise or fall.
We crunched all the numbers in our flight calendar and it looks like the cheapest time to book a flight to Washington D.C. is around 40 days in advance, so don’t leave your flight to the last minute.
Currently, Frontier Airlines and Southwest Airlines offer the cheapest flight tickets to Baltimore Washington International.

Flying from Lambert-St. Louis International Airport (STL) to Baltimore/Wash International Thurgood Marshall Airport (BWI): what you need to know

  • Around 2 hours is how long you can expect to be travelling on a direct flight from Lambert-St. Louis International Airport to Baltimore/Wash International Thurgood Marshall Airport.

  • Washington DC's timezone is UTC-4, which makes Washington DC one hour ahead of St Louis.

  • Flights from STL to BWI start from 05:10 — the first with Southwest Airlines. The latest departure is at 21:25 with Southwest Airlines. Overall, you can choose from 19 weekly Lambert-St. Louis International Airport to Baltimore/Wash International Thurgood Marshall Airport flights.

  • Arriving two hours before an international flight and one hour ahead of a domestic departure are golden rules for hassle-free flying. Make sure you're at the airport on time to board your STL to BWI flight.

  • You can expect longer lines in popular months like July. Arriving up to four hours ahead of international flights and two hours for domestic departures will help ensure a smooth travel experience.

  • Southwest Airlines is your ticket to exploring Washington DC (and perhaps some other exciting corners of United States!). Check out the direct flights from Lambert-St. Louis International Airport to Baltimore/Wash International Thurgood Marshall Airport offered by this carrier.

  • The airline that passengers book most often on this route is Southwest Airlines.

  • Southwest Airlines is the most punctual carrier offering STL to BWI flights, with 79.79% of its services arriving on schedule.

  • If you'd like to add a stop to your trip, just uncheck 'Direct flights only' when searching for your ticket from Lambert-St. Louis International Airport to Baltimore/Wash International Thurgood Marshall Airport. Here are the top stopovers between STL and BWI:

    • Nashville International Airport

    • Detroit Metropolitan Wayne County Airport

    • Chicago Midway International Airport

How to find the cheapest flights from Lambert-St. Louis International Airport (STL) to Baltimore/Wash International Thurgood Marshall Airport (BWI)

  • R 1,039 is currently the best price for a one-way Lambert-St. Louis International Airport to Baltimore/Wash International Thurgood Marshall Airport flight. Return flights start from R 2,430. These fares can change based on availability.

  • To get cheap tickets from STL to BWI, book your trip six months ahead of your departure.

  • The cheapest month for flights from Lambert-St. Louis International Airport to Baltimore/Wash International Thurgood Marshall Airport is May. Use the 'Whole month' tool to see the lowest prices if you have a flexible travel schedule.

  • Finding cheap flights from STL to BWI is a cinch with Price Alerts. All you need to do is create one of these automatic alerts and we'll let you know as soon as a lower fare pops up.

  • Pick your preferred arrival and departure times, airlines and number of stops with the filters. Alternatively, sort your results by 'Cheapest' to get the best deals on flights from Lambert-St. Louis International Airport to Baltimore/Wash International Thurgood Marshall Airport.

Handy information about Lambert-St. Louis International Airport (STL)

Arriving at Baltimore/Wash International Thurgood Marshall Airport (BWI)

Getting from Baltimore/Wash International Thurgood Marshall Airport (BWI) to central Washington DC

  • From Baltimore/Wash International Thurgood Marshall Airport, Washington DC is approximately 48 kilometres away. It takes around 50 minutes to get to the centre driving.

  • When travelling by public transport, expect a journey of around 1 hour 30 minutes.

When to fly to Baltimore/Wash International Thurgood Marshall Airport (BWI)

  • July is the most popular month for flights from Lambert-St. Louis International Airport to Baltimore/Wash International Thurgood Marshall Airport. For smaller crowds, visit Washington DC in May.

  • The warmest month in Washington DC is July, with temperatures ranging between 19ºC (66ºF) and 33ºC (91ºF). Lock in your flights from Lambert-St. Louis International Airport to Baltimore/Wash International Thurgood Marshall Airport in this month if this is the type of weather you like.

  • For cooler conditions, look for a cheap ticket from STL to BWI in January. Temperatures average between -6ºC (21ºF) and 10ºC (50ºF) then.

Explore more of United States

  • New York is just one of the many places in United States waiting to be discovered once you've seen the sights of Washington DC. Around 322 kilometres away to the north-east, its top attractions include Statue of Liberty, Central Park and Empire State Building.

  • Philadelphia is another favourite destination in United States and is around 193 kilometres north-east of Washington DC. No journey is complete without seeing Liberty Bell, Independence Hall and Philadelphia Museum of Art.

Prices shown on this page are estimated lowest prices only. Found in the last 45 days.