$84 Find Cheap Flights from St. Louis to Washington

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from St. Louis to Washington departing on 9/3. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy

KAYAK searches hundreds of travel sites at once for deals on flights to Washington

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to Washington.
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to Washington.
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Cheap Flights from St. Louis to Washington

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours
Seattle
Seattle1 stop$168
Spokane
Spokane1 stop$235
Pasco
Pasco2 stops$254
Pullman
Pullman1 stop$386
Seattle
Seattle1 stop$168
Spokane
Spokane1 stop$235
Pasco
Pasco2 stops$254
Pullman
Pullman1 stop$386

Book Cheap St. Louis to Washington Plane Tickets

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from St. Louis to Washington that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from St. Louis to Washington

Sat, Sep 20 - Tue, Sep 23
United Airlines Logo
5:49 pm - 10:59 pmSTL-SEA
7h 10m1 stop
United Airlines Logo
7:00 am - 3:44 pmSEA-STL
6h 44m1 stop
$168United Airlines
Find Deal
Tue, Sep 9 - Wed, Sep 17
Delta Logo
3:30 pm - 8:24 pmSTL-SEA
6h 54m1 stop
Delta Logo
7:10 am - 6:02 pmSEA-STL
8h 52m1 stop
$177Delta
Find Deal
Fri, Jan 23 - Mon, Jan 26
American Airlines Logo
5:57 am - 12:32 pmSTL-SEA
8h 35m1 stop
American Airlines Logo
12:27 am - 11:44 amSEA-STL
9h 17m1 stop
$214American Airlines
Find Deal
Sat, Aug 30 - Sat, Sep 6
Hawaiian Airlines Logo
6:00 am - 8:30 amSTL-SEA
4h 30mnonstop
Hawaiian Airlines Logo
8:36 am - 2:39 pmSEA-STL
4h 03mnonstop
$216Hawaiian Airlines
Find Deal
Wed, Aug 27 - Wed, Sep 3
Alaska Airlines Logo
6:00 am - 8:30 amSTL-SEA
4h 30mnonstop
Alaska Airlines Logo
8:36 am - 2:39 pmSEA-STL
4h 03mnonstop
$217Alaska Airlines
Find Deal
Tue, Sep 9 - Thu, Sep 11
Alaska Airlines Logo
3:35 pm - 5:54 pmSTL-SEA
4h 19mnonstop
Alaska Airlines Logo
8:36 am - 2:39 pmSEA-STL
4h 03mnonstop
$227Alaska Airlines
Find Deal
Mon, Sep 15 - Mon, Sep 22
Hawaiian Airlines Logo
3:35 pm - 5:54 pmSTL-SEA
4h 19mnonstop
Hawaiian Airlines Logo
6:03 pm - 11:59 pmSEA-STL
3h 56mnonstop
$232Hawaiian Airlines
Find Deal
Tue, Sep 9 - Fri, Sep 12
Southwest Logo
3:00 pm - 8:30 pmSTL-PDX
7h 30m1 stop
Southwest Logo
9:05 pm - 11:30 amPDX-STL
12h 25m2 stops
$234Southwest
Find Deal
Sat, Aug 23 - Sat, Aug 30
Southwest Logo
1:45 pm - 9:00 pmSTL-SEA
9h 15m1 stop
Southwest Logo
11:10 pm - 9:10 amSEA-STL
8h 00m1 stop
$236Southwest
Find Deal
Sat, Aug 23 - Fri, Aug 29
American Airlines Logo
1:42 pm - 11:26 pmSTL-PDX
11h 44m1 stop
American Airlines Logo
10:23 am - 8:18 pmPDX-STL
7h 55m1 stop
$253American Airlines
Find Deal
Booking Insights

KAYAK's insights & trends for St. Louis to Washington flights

Get data-powered insights and trends into flights from St. Louis to Washington to help you find the cheapest flights, the best time to fly and much more.

What is the cheapest St. Louis to Washington flight route?

The cheapest price for flight routes found by users searching on KAYAK in the last 2 weeks for round-trip flights from St. Louis to Washington.

The cheapest ticket to Washington from St. Louis found in the last 72 hours was to Seattle, at $232 round-trip. The most popular route is from St. Louis (STL) to Seattle (SEA), and the cheapest round-trip airline ticket found on this route in the last 72 hours was $232.

Can I save money by flying with a layover from St. Louis to Washington?

The average round-trip price for all non-stop flights, flights with one layover, and flights with two layovers for the route found by users searching on KAYAK in the last 2 weeks.

Yes, flying with a layover may cost you more time, but you can also save money on the route, with a 2 stops layover the cheapest option at $416 on average.

What is the cheapest month to fly from St. Louis to Washington?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from St. Louis to Washington, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from St. Louis to Washington is September, when tickets cost $288 (return) on average. On the other hand, the most expensive months are July and June, when the average cost of round-trip tickets is $458 and $428 respectively.

What’s the cheapest day of the week to fly from St. Louis to Washington?

The average price of all round-trip flights from St. Louis to Washington clicked on KAYAK for each day over the last 12 months.

Your flight ticket price will generally be cheaper if you fly to Washington on a Wednesday and more expensive on a Sunday. On your return trip to St. Louis, you should consider flying back on a Thursday, and avoid Sundays for better deals.

How far in advance should I book a flight from St. Louis to Washington?

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from St. Louis to Washington, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from St. Louis to Washington, you should book around 4 weeks before departure, which saves you about 43% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 11 weeks before departure.


Good to know

Low seasonJanuary
Cheapest flight$84
Best time to beat the crowds with an average 11% drop in price.
Most popular time to fly with an average 5% increase in price.
Flight from St. Louis to Seattle

FAQs - booking Washington flights

  • How does KAYAK find such low prices on flights from St. Louis to Washington?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from St. Louis to Washington.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from St. Louis to Washington?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight from St. Louis to Washington is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from St. Louis to Washington?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly from St. Louis to Washington with an airline and back with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from St. Louis to Washington?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying from St. Louis to Washington up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • What is the cheapest time of day to fly to Washington?

    The cheapest time of day to fly to Washington is generally in the evening, when round-trip flights cost $449 on average. Morning departures are around 13% more expensive than evening flights, on average. The most expensive time of day to fly to Washington is generally in the afternoon, which is peak travel time and where the average cost of a ticket is $509.

Top tips for finding cheap flights to Washington

  • Looking for a cheap flight? 25% of our users found tickets from St. Louis to the following destinations at these prices or less: Seattle $223 one-way - $343 round-trip

Reviews of the top 5 airlines serving from St. Louis to Washington

 
See real verified KAYAK customer reviews for airlines flying from St. Louis to Washington. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from St. Louis to Washington? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
Alaska AirlinesOverall score based on 10000 reviews
8.1Boarding
7.1Entertainment
7.8Comfort
7.1Food
8.5Crew
Airline reviews

Very nice as always. Not that it’s anyone’s fault really but for some reason the seat (16C) was really hard…. Not typical for your planes… dunno what or why… maybe it was just me ?, The flight was great otherwise

10.0 ExcellentLee, Jul 2025ORD - SEA
Read more Alaska Airlines reviews

Very nice as always. Not that it’s anyone’s fault really but for some reason the seat (16C) was really hard…. Not typical for your planes… dunno what or why… maybe it was just me ?, The flight was great otherwise

My experience was great with Alaska Airlines. They were very helpful when I was checking in. The flight crew was very helpful with our needs.

Crew members were friendly, but I wouldn’t use “entertaining” to describe them. Exact step by step instructions on getting wi-fi on the phone would be helpful.

Ease of reservations, confirmation. Cramped seating, very, very uncomfortable! Claustrophobic.

My husband unfortunately had a very large lady next to him who did not fit in the seat and had to have the armrest up so she was partially in his seat and she also had horrible BO

I liked the legroom even in row 26! I fell asleep immediately and slept the whole flight.

delayed flight 3 hours, then took 45 min to get to gate and another 10 min to open door

The plane was put out of service and had to wait for a new plane to be assigned. No one had any information and the information on the screens was never updated. The call wait time was 2 hours and the estimated time for text assistance was 55 minutes which was a lie because after 55 minutes nothing happened. I understand that delays happen but to not have anyone available to provide any update or reassurance was just negligent. Also, what is the point of having an 800 number if no one answers it and don’t get me started on the text message system. Ridiculous!

Very good; ohana atmosphere and taking care of customer care

Flight was delayed an hour, so that was inconvenient. But they tried to make it up in the air, which I appreciated. Crew was very nice, service was excellent. Description of food didn’t quite match what was served, but it was tasty. 👍🏽

southwest just starting charging for luggage. hadnt realized it until it was too late. now out $70 when i couldve bought a carry on if i wouldve known. free bags was one of the only reasons i chose southwest over another airline (the other being no assigned seats, which is apparently also being changed). stupid business decision. wont be flying southwest anymore.

The quality of Southwest Airlines continues to degrade each time I fly with them. If it were not for the free luggage, I would probably choose another airline. Their prices are a little bit competitive, but way too high for the quality of the service. Southwest is not unique in this way. Domestic flight in the United States of America has continued to be a lower and lower quality product. Very sad when you compare the quality of domestic airlines to that of many international airlines around the world.

Very smooth checking in our luggage with a super pleasant SW agent. I enjoyed a fun entertaining movie.

WiFi did not work. For as outrageous as these flights cost, when they’re advertised with certain services/ features they should be in working order

Worst experience I had on Southwest. Still better than most, but the seating was barely tolerable.

The Southwest employees (all two of them) were very nice and cheerful despite the fact the line to self-check a bag (simply drop it off) was hundreds of people long. Thank God I arrived early to the airport because I stood in this line for at least an hour. Once on the flight that had been delayed by an hour, we had no Wi-Fi and thus no entertainment. Finally, I hope the investor strong arm tactics against Southwest pay off in a short-term windfall to your C-Suite because the rest of you are screwed. I have been a faithful Southwest customer for 15 years due to everything you just got rid of. I'm flying to Idaho and Washington in October, both places I used to simply book with Southwest without a second thought now with Frontier (Washington) and United (Idaho) because they offer everything the "new" Southwest does but cheaper and at better times, destinations, etc. This really makes me sad...

It was okay. The plane was delayed from earlier in the day, but they kept updating the departure time, sometimes later, sometimes earlier. That was stressful. Once we finally got on and took off, it was fine. I was supposed to have a connection in Chicago to Los Angeles, and the time for so late I was rebooked to arrive in LA 3 hours late. The departure time to Chicago later became early enough to have taken my original connection and arrive earlier but that wasn't an option.

It was one and half hour late... Not sure if any other experience matters.

Delayed flight. Nicest crew member was a SW pilot flying seated next to me who kindly move to seat the final passenger. Flight extra delayed. My cup of refreshment of ginger ale was so packed with ice it was literally 2 sips.

For my birthday trip this was my second time ever flying, this trip was the best.

My experience on any Delta flight is always overshadowed by the time Delta removed me from a flight for no apparent reason.

Check in process was terrible. Lady at counter didn’t know what she was doing

Delayed and took off even later than the scheduled delay time

For a 69 year old with health problems I had the worse experience, no wheelchair when I entered a lady told me to sit and wait while a gentleman told me I had to walk to the Delta station, which I did. I had a carry on and a bag, and I was traveling with my service dog, which was on his carrier and the lady charged me for my carry on luggage, beside all the waiting cause of the delay, I had to walk to get my luggage cause no wheelchair showed up, I am so disappointed. I will get in touch with the company. I got home at 3:00 am, not good for my health situation.

Great experience on Delta. Staff from baggage check to flight attendants were very courteous and professional. My only issue was a personal preference for pretzels instead of the chips and cookies that were offered.

My flight was canceled after being rescheduled for four days canceling my trip. Kayak and everyone affiliated with it I.e the airlines, and just fly have been excruciating to deal with. My trip to visit family had to be canceled as there was no way to make it. I am furious at all of you.

They delayed our flight because of bad weather in NY which was completely understandable. Then they cancelled our flight and a later flight that evening. The earliest we could fly was the next morning. We ended up buying last minute tickets on another airline and made it home slightly delayed but safely that evening. Delta kept saying it was weather related but if that was the case how did we make it back on another airline? The weather in NY was cloudy but not bad.

There was a security issue at the airport and we were unable to land. We circled endlessly and then landed at another airfield for fuel. We then circled the airport again, almost landed but didn’t fully touch down before circling again. I am thankful to the crew for keeping us safe- the issue was the airline and staff at the airport getting us seats on our connecting flights. That part was hours of searching for someone and getting in double my steps.

Boarding was organised and relaxed. Crew were fantastic! Seats were lacking padding causing butt pain and stiffness.

Food from the flight from Atlanta to Santiago was very poor..

The flight was supposed to leave at 7:30pm, but departed 10:50pm. They kept moving departure time out every half hour. It was a 45 minute flight from n Sunday night with great weather.

Flight got delayed and it was very inconvenient . Had to come with another carrier. Had to spend one more night in San Francisco.

Logging into next flight was an issue as I never received a confirmation code

Alaska airlines is not what I expected Very disappointed Unfriendly Discouraging Very bad customer service, heartbroken trying to explain to them my situation.

I could not check in ahead of time. Kayak did not give me a proper confirmation number to check in.

I loved flying Hawaiian Air! We didn’t pay to sit together, but we were able to anyway. They had usb charging ports and even outlets in some seats. They served a hot sandwich that was not very good, but we were still pleasantly surprised. The staff was very nice. The seats really made my booty hurt but maybe I’m just not used to sitting so long. Also, the AC was really cold even though I was wearing pants, a hoodie, and a light blanket.

The crew was great, the food is decent for airline food, and we flew economy but the seats are comfortable and had plenty of room for my 15 year old son and myself. Would fly Hawaiian Airlines again for a long haul flight in a heartbeat.

A second drink service on a 6 hour flight would have been helpful.

The steward staff was particularly friendly and helpful. They smiled a lot and seemed anxious to be sure we enjoyed the flight.

Everything was good for the price I paid. Crew was very nice.

We had to turn around and head back to Manchester. Problem with a plane engine.

Flight was delayed. Staff at the gate effectively and proactively communicated about the delay.

Very poor delay in dfw was really bad n long

Our flight was 1.5 hours delayed. There was no weather for the inbound flight, so I don't understand why. This meant a VERY late arrival and only a quick nap before my morning flight.

Because of rescheduling, they had to put me on a flight that didn't go through Dallas

It was very difficult to stretch my knee out and I am very short. I also had a torn tendon in my knee which made it extra uncomfortable anyways. My husband is 6'2" and I can't imagine him flying in that plane.

3 hour weather delay followed by 1 hour (and counting) maintenance delay. UGH!

Couldn’t get the door on the plane to close leading to a nearly 2 hour delay. But, hey at least they didn’t cancel the flight.

Flight was cancelled 3 hrs AFTER etd. Thetefore Missed connection from JFK to New Zealand . No accommodation provided… This cost ne aporox 1000 USD in extra expenses and turned whst should have been a 24 hr trip ftom Boston - New Zealand into a VERY expensive , late 70+ hr nightmare … Complete nonsense!!!

After we'd boarded , they canceled the flight. The crew didn't even know , we just all received text messages. Then after they deplaned us , AA was just like "too bad, go F your self, we sure ain't gonna help you"

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