Cheap flights from Washington, D.C. to St. Louis from $66
This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Washington, D.C. to St. Louis departing on 12/2. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Frontier flights from Washington, D.C. to St. Louis
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Fly from
Fly to
Route
Depart
Return
BaltimoreSt. Louis
BWI Baltimore/Washington - STL Lambert-St Louis
BWISTL
Baltimore/Washington
Thu 10/29
2:07 pm-11:19 am
1 stop22h 12m
Lambert-St Louis
Mon 11/2
12:14 pm-11:08 am
1 stop21h 54m
BaltimoreSt. Louis
BWI Baltimore/Washington - STL Lambert-St Louis
BWISTL
Baltimore/Washington
Thu 11/12
8:41 pm-5:42 pm
1 stop22h 01m
Lambert-St Louis
Mon 11/16
6:34 pm-9:46 am
1 stop14h 12m
BaltimoreSt. Louis
BWI Baltimore/Washington - STL Lambert-St Louis
BWISTL
Baltimore/Washington
Wed 11/11
4:50 pm-7:25 pm
1 stop3h 35m
Lambert-St Louis
Sat 11/14
10:35 am-5:05 pm
1 stop5h 30m
BaltimoreSt. Louis
BWI Baltimore/Washington - STL Lambert-St Louis
BWISTL
Baltimore/Washington
Wed 12/9
4:50 pm-7:25 pm
1 stop3h 35m
Lambert-St Louis
Sat 12/12
10:35 am-5:05 pm
1 stop5h 30m
BaltimoreSt. Louis
BWI Baltimore/Washington - STL Lambert-St Louis
BWISTL
Baltimore/Washington
Thu 1/21
6:21 pm-11:57 pm
1 stop6h 36m
Lambert-St Louis
Tue 1/26
10:27 am-4:12 pm
1 stop4h 45m
BaltimoreSt. Louis
BWI Baltimore/Washington - STL Lambert-St Louis
BWISTL
Baltimore/Washington
Tue 11/17
11:00 am-5:29 pm
1 stop7h 29m
Lambert-St Louis
Wed 11/18
10:37 am-5:00 pm
1 stop5h 23m
BaltimoreSt. Louis
BWI Baltimore/Washington - STL Lambert-St Louis
BWISTL
Baltimore/Washington
Thu 1/14
6:05 am-10:35 am
1 stop5h 30m
Lambert-St Louis
Tue 1/19
8:15 am-2:24 pm
1 stop5h 09m
BaltimoreSt. Louis
BWI Baltimore/Washington - STL Lambert-St Louis
BWISTL
Baltimore/Washington
Fri 10/30
10:09 am-3:43 pm
1 stop6h 34m
Lambert-St Louis
Mon 11/2
1:08 pm-7:09 pm
1 stop5h 01m
Washington, D.C.St. Louis
IAD Washington, D.C. Dulles Intl - STL Lambert-St Louis
IADSTL
Washington, D.C. Dulles Intl
Thu 10/29
6:05 am-9:49 am
1 stop4h 44m
Lambert-St Louis
Thu 10/29
7:20 pm-12:42 am
1 stop4h 22m
Washington, D.C.St. Louis
IAD Washington, D.C. Dulles Intl - STL Lambert-St Louis
IADSTL
Washington, D.C. Dulles Intl
Mon 11/2
6:12 pm-11:54 pm
1 stop6h 42m
Lambert-St Louis
Wed 11/4
6:00 am-2:09 pm
1 stop7h 09m
See travel insights to St. Louis from
How to get the cheapest flight ticket from Washington, D.C. to St. Louis
Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip
What is the typical price of a round-trip flight between Washington, D.C. and St. Louis?
Prices are currently low for flights on this route.
Typical prices usually range from $269 to $505.The lowest price recently found on this route was $116.
What is the cheapest month to fly to St. Louis?
In general, January is the cheapest month to fly from Washington, D.C. to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $350. The month of April is another great option to travel to St. Louis, with average flight prices from Washington, D.C. averaging around $352.
What is the cheapest day to depart on your flight to St. Louis?
The cheapest day to depart on your flight to St. Louis is on a Wednesday when prices can be found for as low as $360. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Sunday because tickets tend to average around $484. These prices are subject to change though, so be sure to set up a Price Alert for flights to St. Louis.
What is the cheapest time of day to depart on your flight to St. Louis?
Flying to St. Louis from Washington, D.C. at noon is the least expensive time of day to depart. momondo users have found prices as low as $375 when looking at flights departing at noon. In the afternoon is when there is more demand to fly to St. Louis, so prices are often more expensive at around $429 per ticket.
What is the cheapest Washington, D.C. to Lambert-St Louis flight route?
Fly from Washington, D.C. Reagan-National to Lambert-St Louis for the best Washington, D.C. - Lambert-St Louis flight prices
What cabin class options are available on Washington, D.C. to St. Louis flights?
There are 4 cabin classes available to choose from on Washington, D.C. to St. Louis flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.
Can stopping save me money on Washington, D.C. to St. Louis flights?
You could potentially save up to 4% on your flight if you consider stops on a Washington, D.C. to St. Louis flight.
What is the cheapest airline that flies from Washington, D.C. to Lambert-St Louis?
Frontier and Southwest are the most popular carriers operating from Washington, D.C. to Lambert-St Louis
What airlines fly to St. Louis?
Southwest, United Airlines and American Airlines are the top three most popular airlines that fly to St. Louis from Washington, D.C. according to our data. Southwest is the first choice among our users, with 56% of people opting to fly with this airline when traveling to St. Louis. Keep in mind that there are 5 different airlines that fly to St. Louis on a routine basis, so you have a few additional options to choose from.
Which airport is the most popular layover for flights between Washington, D.C. and St. Louis?
Denver (DEN) was the most common stop: 67% of momondo users choosing 1-stop flights on this route connected there.
Which layover airport offers the lowest fares from Washington, D.C. to St. Louis?
Flights via Denver (DEN) offer the lowest average round-trip price of $270.
Which layover airport has the shortest travel time from Washington, D.C. to St. Louis?
Flights connecting via Nashville (BNA) have the shortest average one-way travel time: 4h 25m.
Which layover airport has the shortest connection time from Washington, D.C. to St. Louis?
Nashville (BNA) has the shortest average layover time for this route: 1h 10m.
How many flights depart from Washington, D.C. to St. Louis on average per day?
As of October 2026, 18 flights take off from Washington, D.C. and land in St. Louis each day. The most common flight departure time for this route is 5:00PM, with 53% of daily flights taking off in the afternoon.
How many flights depart from Washington, D.C. to St. Louis on average per week?
As of October 2026, there are 127 flights per week flying from Washington, D.C. to St. Louis. The most common day of the week flights depart is Mon, with 17% of flights taking off on this day.
When to book flights from Washington, D.C. to St. Louis
Cheap Washington, D.C. to St. Louis (WAS to STL) flight deals and tips
Find info about flight duration, direct flights, and airports for your flight from Washington, D.C. to St. Louis
Frequently asked questions about flying from Washington, D.C. to St. Louis
How far is Washington, D.C. to Lambert-St Louis by plane?
There are 708.3 mi between Washington, D.C. and Lambert-St Louis. 2h 15m is a normal flight duration for this route.
When did momondo last update prices for flights from Washington, D.C. to Lambert-St Louis Airport?
Prices for flights from Washington, D.C. to Lambert-St Louis Airport are updated daily.
How many operators does momondo search for flights from Washington, D.C. to Lambert-St Louis Airport?
The number of operators available for flights from Washington, D.C. to Lambert-St Louis Airport is 5 as of October 2026.
How old do you have to be to fly from Washington, D.C. to Lambert-St Louis Airport?
The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Washington, D.C. to Lambert-St Louis Airport.
What documentation or ID do you need to fly to Lambert-St Louis Airport?
The required travel and health documents for your Lambert-St Louis Airport trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Lambert-St Louis Airport. We recommend that you seek guidance from your airline or a reliable third party such as IATA.
What is the most popular plane model from Washington, D.C. to St. Louis?
Based on momondo bookings for this flight route, the most popular plane model on flight routes from Washington, D.C. to St. Louis is Boeing 737 MAX 8 (19.53% of total bookings). The next most popular plane models are Boeing 737-800 Passenger/BBJ2 (winglets) (15.13%), Embraer 175 (14.41%), and Canadair (Bombardier) Regional Jet CRJ-550 (12.30%).
What is the most popular airline from Washington, D.C. to St. Louis?
momondo data reveals that the most frequently booked airline on the route from Washington, D.C. to St. Louis is Southwest, representing 66% of all bookings. The subsequent popular airlines are American Airlines at 24%, United Airlines at 4%, and Frontier at 4%.
Best airlines flying from Washington, D.C. to St. Louis
Compare and see reviews for airlines that fly from Washington, D.C. to St. Louis with momondo
| Airline | Rating | Free Cancellation | Price | ||
|---|---|---|---|---|---|
| PriceFrom $78 | Free Cancellation | Rating 5.6 2,551 reviews | |||
| PriceFrom $124 | Free Cancellation | Rating 7.8 8,646 reviews | |||
| PriceFrom $231 | Free Cancellation | Rating 7.0 12,146 reviews | |||
| PriceFrom $237 | Free Cancellation | Rating 7.9 4,224 reviews | |||
| PriceFrom $278 | Free Cancellation | Rating 7.4 10,322 reviews |
Southwest Flights From Washington, D.C. to St. Louis
Southwest operates around 21 flights from Washington, D.C. to St. Louis every week. The average price of these flights found in the last 72 hours has been $435, but momondo users have found Southwest deals from Washington, D.C. to St. Louis from as low as $237 round-trip. Southwest has been scored 7.9/10 in 4,222 reviews.
United Airlines Flights From Washington, D.C. to St. Louis
United Airlines (7.4/10 from 10,319 reviews) operates around 13 flights from Washington, D.C. to St. Louis in any given week. The average United Airlines airfare for this route is around $564, with deals from around $278 rare but found on momondo. Referenced prices are for round-trip Washington, D.C. to St. Louis flight searches in the last 72 hours.
Traveling to a place near St. Louis?
Book flights to St. Louis if you plan to visit one of these locationsWhy use momondo?
Why should I use momondo to find a flight deal from Washington, D.C. to St. Louis?
To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to St. Louis from Washington, D.C..
Can I find flights from Washington, D.C. to St. Louis with flexible booking policies on momondo?
Yes. momondo allows you to filter the results for Washington, D.C. to St. Louis flights to just show those with flexible booking policies.
How can momondo help me find flights from Washington, D.C. to St. Louis?
momondo helps you find the best flight between Washington, D.C. and St. Louis by providing filters to narrow your choice of flights to those matching your criteria. You can select flights based on numerous factors such as price, departure and landing times, airport and airline.
I’m not ready to book a flight from Washington, D.C. to St. Louis right now. Can momondo alert me if prices change?
If you are simply researching potential flights to St. Louis, momondo offers a useful price alert feature which will track prices for flights to St. Louis from Washington, D.C. and alert you when they change.