Cheap flights from Washington, D.C. to St. Louis from $52
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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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?
What is the cheapest month to fly to St. Louis?
In general, August 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 $279. The month of May is another great option to travel to St. Louis, with average flight prices from Washington, D.C. averaging around $297.
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 $349. 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 $412. 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. in the evening is the least expensive time of day to depart. momondo users have found prices as low as $314 when looking at flights departing in the evening. In the afternoon is when there is more demand to fly to St. Louis, so prices are often more expensive at around $384 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
How far in advance should I book a flight to St. Louis?
You are more likely to see cheaper flights to St. Louis from Washington, D.C. when booking weeks ahead of your departure date. In general, you can expect to find flights to St. Louis for around $410 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to St. Louis from Washington, D.C. for as low as $303 on momondo.
What cabin class options are available on Washington, D.C. to Lambert-St Louis flights?
There are 4 cabin classes available to choose from on Washington, D.C. to Lambert-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?
No. A direct flight is the cheapest option for a flight between Washington, D.C. to St. Louis.
How have Washington, D.C. to St. Louis flight prices changed over time?
As of July 2025, prices for Washington, D.C. to St. Louis flights are approximately 25% cheaper when compared to flights at the same time last year.
What is the cheapest airline that flies from Washington, D.C. to Lambert-St Louis?
American Airlines, United Airlines, and Southwest are the most popular carriers operating from Washington, D.C. to Lambert-St Louis
What airlines fly to St. Louis?
Southwest, American Airlines and United 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 45% 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.
How many flights depart from Washington, D.C. to St. Louis on average per day?
As of July 2025, 17 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 51% 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 July 2025, there are 125 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
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 10m 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 July 2025.
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 (17.26% of total bookings). The next most popular plane models are Boeing 737-700 Passenger/BBJ1 (winglets) (17.04%), Boeing 737-800 Passenger/BBJ2 (winglets) (13.87%), and Canadair (Bombardier) Regional Jet 700 (13.39%).
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 50% of all bookings. The subsequent popular airlines are American Airlines at 39%, United Airlines at 6%, and Delta at 2%.
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 $108 | Free Cancellation | Rating 5.9 3,273 reviews | |||
| PriceFrom $158 | Free Cancellation | Rating 7.2 10,000 reviews | |||
| PriceFrom $169 | Free Cancellation | Rating 8.0 7,958 reviews | |||
| PriceFrom $198 | Free Cancellation | Rating 8.0 4,256 reviews | |||
| PriceFrom $259 | Free Cancellation | Rating 7.4 8,844 reviews |
Southwest Flights From Washington, D.C. to St. Louis
Southwest operates around 27 flights from Washington, D.C. to St. Louis every week. The average price of these flights found in the last 72 hours has been $347, but momondo users have found Southwest deals from Washington, D.C. to St. Louis from as low as $198 round-trip. Southwest has been scored 8.0/10 in 4,258 reviews.
United Airlines Flights From Washington, D.C. to St. Louis
United Airlines (7.4/10 from 8,844 reviews) operates around 14 flights from Washington, D.C. to St. Louis in any given week. The average United Airlines airfare for this route is around $476, with deals from around $259 rare but found on momondo. Referenced prices are for round-trip Washington, D.C. to St. Louis flight searches in the last 72 hours.
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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.