STL - SEA

$75 Find Cheap Flights from St. Louis to Seattle

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 Seattle departing on 10/18. 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 Seattle

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to Seattle.
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to Seattle.
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Flight Deals

Cheap Flights from St. Louis to Seattle (STL-SEA)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from St. Louis to Seattle 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 Seattle

Thu, Oct 16 - Sun, Oct 19
 Logo
3:57 pm - 6:25 pmSTL-SEA
4h 28mnonstop
 Logo
8:43 pm - 9:07 amSEA-STL
10h 24m1 stop
Wed, Dec 24 - Sun, Dec 28
Southwest Logo
4:45 pm - 10:55 pmSTL-SEA
8h 10m1 stop
Southwest Logo
5:00 am - 12:20 pmSEA-STL
5h 20m1 stop
$223Southwest
Find Deal
Sat, Oct 18 - Sat, Oct 25
Hawaiian Airlines Logo
6:33 am - 9:05 amSTL-SEA
4h 32mnonstop
Hawaiian Airlines Logo
6:02 pm - 12:03 amSEA-STL
4h 01mnonstop
$231Hawaiian Airlines
Find Deal
Wed, Oct 1 - Tue, Oct 7
Delta Logo
5:32 pm - 11:43 pmSTL-SEA
8h 11m1 stop
Delta Logo
6:00 am - 2:32 pmSEA-STL
6h 32m1 stop
$232Delta
Find Deal
Sat, Oct 18 - Sat, Oct 25
Hawaiian Airlines Logo
6:33 am - 9:05 amSTL-SEA
4h 32mnonstop
Hawaiian Airlines Logo
6:02 pm - 12:03 amSEA-STL
4h 01mnonstop
$235Hawaiian Airlines
Find Deal
Sat, Nov 8 - Tue, Nov 11
Alaska Airlines Logo
7:00 am - 9:33 amSTL-SEA
4h 33mnonstop
Alaska Airlines Logo
9:15 am - 3:18 pmSEA-STL
4h 03mnonstop
$237Alaska Airlines
Find Deal
Wed, Oct 1 - Wed, Oct 8
American Airlines Logo
5:18 am - 10:50 amSTL-SEA
7h 32m1 stop
American Airlines Logo
2:52 pm - 11:54 pmSEA-STL
7h 02m1 stop
$238American Airlines
Find Deal
Thu, Nov 6 - Mon, Nov 10
Delta Logo
6:00 am - 10:45 amSTL-SEA
6h 45m1 stop
Delta Logo
11:55 pm - 8:55 amSEA-STL
7h 00m1 stop
$243Delta
Find Deal
Fri, Oct 31 - Sat, Nov 1
American Airlines Logo
7:16 am - 12:37 pmSTL-SEA
7h 21m1 stop
American Airlines Logo
12:59 am - 10:39 amSEA-STL
8h 40m1 stop
$253American Airlines
Find Deal
Sat, Sep 27 - Sat, Oct 4
Alaska Airlines Logo
3:35 pm - 5:54 pmSTL-SEA
4h 19mnonstop
Alaska Airlines Logo
6:02 pm - 12:03 amSEA-STL
4h 01mnonstop
$296Alaska Airlines
Find Deal

Everything you should know

Our travelers' advice
AI-generated summary based on content written by travel experts
Avoid peak hours at STL to reduce security wait times.
Use the Link light rail from SEA for a smooth downtown trip.
Expert advice
Expert advice
Expert advice
Expert advice
Top airlines
Southwest
Cheapest • from $223 (round-trip)
Alaska Airlines
Best reviews • 8.0 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
Video guide: How to find cheap flights to Seattle
Watch video
Watch video
Watch video
Watch video
When to book
3 weeks
in advance
Our data shows that travelers who book at least 3 weeks in advance save around 32% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
October
Cheapest • 18% price drop
July
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
Cheapest round-trip
$221
Typical prices: $237-406
Multiple Airlines
Thu 10/16Sun 10/19
STL - SEA • Non-stop
Cheapest non-stop
$231
Typical prices: $243-434
Hawaiian Airlines
Sat 10/18Sat 10/25
STL - SEA • Non-stop
Start a new search
KAYAK searches 100s of sites at once to find you the best travel deals.
We hope you love your trip to Seattle!
Expert advice

Expert advice for your flight from St. Louis to Seattle

 
Snippets provided in this section are AI-generated based on a summarization of KAYAK-commissioned articles. The articles are presented as-is, for general informational purposes only, and may not be up-to-date. The opinions contained in the articles are original to the author and reflect their authentic experience, which may vary significantly from the experience of others.
KAYAK teamed up with top travel experts to share the best tips for your journey.
Airports
STL

Avoid peak hours at STL to minimize wait times at security and baggage claim, especially in Terminal 2.

Read more about STLby Yulia Denisyuk
SEA

Use the Link light rail for a cost-effective and reliable trip from SEA to downtown Seattle, avoiding traffic.

Read more about SEAby Harriet Baskas
Our travel experts
Yulia Denisyuk

Yulia Denisyuk

Expert on STL

Yulia Denisyuk

Yulia Denisyuk

Yulia is a freelance journalist who’s dispatched from 90+ countries. Her work focuses on cultures, adventure trips and air travel, appearing in NatGeo, NYT, CNTraveler, and more. For past assignments, she’s stayed with nomads in Mongolia and learned the art of Imigongo in Rwanda. She’s based in Chicago; in winter she often questions that decision.

Read more
Harriet Baskas

Harriet Baskas

Expert on SEA

Harriet Baskas

Harriet Baskas

Harriet is an award-winning journalist who is happiest in an airport or an unusual museum. Her stories about airports, air travel, and the business of travel have appeared on NBC News, CNBC, USA TODAY, The Points Guy and other outlets. She is the creator of the StuckatTheAirport.com blog and the author of nine books. When not out on the road or exploring the latest airport amenities, she’s home in Seattle getting ready for the next adventure.

Read more
Booking Insights

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

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

Find cheap flights to Seattle
Find cheap flights to Seattle

Planning a trip from St. Louis to Seattle? KAYAK’s data-powered insights will help you find cheap flights. Learn the best time to fly, how early to book your ticket, and other tips to secure great prices.

How much is a round-trip flight from St. Louis to Seattle?

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

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

For St. Louis to Seattle, Tuesday is the cheapest day to fly on average and Sunday is the most expensive. Flying from Seattle back to St. Louis, the best deals are generally found on Thursday, with Sunday being the most expensive.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from St. Louis to Seattle, 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 Seattle is October, where tickets cost $289 (return) on average. On the other hand, the most expensive months are July and June, where the average cost of round-trip tickets is $453 and $439 respectively.

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

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.

No, with an average price for the route of $308, prices are generally cheapest when you fly direct.

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

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 Seattle, 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 Seattle, you should book around 3 weeks before departure, which saves you about 32% 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$75
Best time to beat the crowds with an average 4% drop in price.
Most popular time to fly with an average 27% increase in price.
Flight from St. Louis to Seattle

When to book flights from St. Louis to Seattle

Are your dates flexible? Find out the best times to travel from St. Louis to Seattle based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking flights from St. Louis to Seattle

  • How far is downtown Seattle from Seattle Tacoma International Airport?

    Downtown Seattle is about 15 miles away from the airport. There are multiple ways to get there, although they all vary in cost, speed, and convenience. For instance, the fastest way to downtown Seattle would be by taking a taxi. They can easily be found on the third floor of the parking garage and take less than 25min. Alternatively, you can opt for public transport, which is significantly cheaper but slower than a taxi. To board your train, just head to the bridge on the fourth floor of the parking garage where the terminal is located.

  • Does Seattle Tacoma Airport offer wheelchair services?

    Seattle Airport offers complimentary wheelchair services to aid travelers in getting from the plane to baggage claim to the ground transportation center with ease. However, due to logistics reasons, the airport mainly works with the airlines to provide these services. Therefore, the best way to get wheelchair assistance would be by booking with your airline, which will then put on a note on your reservation record informing the airport that you require special assistance.

  • Is on-site parking available at St. Louis Lambert International Airport?

    St. Louis Lambert Airport has plenty of on-site parking options. Two are specially dedicated for long-term parking. They include Long-Term Parking Lot B and Long-Term Parking Lot C, which is split into a covered and uncovered section. Long-Term Parking Lot B is located past Daily Parking Lot A east of the terminal, while Parking Lot C is situated southwest of the airport.

  • Which airline has a lounge in St Louis Lambert Airport?

    St. Louis Lambert Airport has about four lounges for guests to hang out and relax while waiting for their boarding call. The American Airlines Admirals Club is located Airside on Terminal 1 near Gate C1. The Wingtips Lounge, which is open to all travelers regardless of the airline, is located in Terminal 2 near Gate E22. Here you can find a range of snacks and beverages as well as a TV, charging stations, and Wi-Fi in case you need to send a few emails before boarding your flight.

  • What is the cheapest flight from St. Louis to Seattle?

    In the last 3 days, the lowest price for a flight from St. Louis to Seattle was $75 for a one-way ticket and $221 for a round-trip.

  • Do I need a passport to fly between St. Louis and Seattle?

    No

  • Which airlines offer Wi-Fi service onboard planes from St. Louis to Seattle?

    All the following airlines offer inflight Wi-Fi service on the St. Louis to Seattle flight route: Alaska Airlines, Hawaiian Airlines, American Airlines, Delta, United Airlines, and Lufthansa.

  • Which aircraft models fly most regularly from St. Louis to Seattle?

    The Boeing 737 is the aircraft model that flies most regularly on the St. Louis to Seattle flight route.

  • Which airline alliances offer flights from St. Louis to Seattle?

    oneworld is the only airline alliance operating flights between St. Louis and Seattle.

  • On which days can I fly direct from St. Louis to Seattle?

    There are nonstop flights from St. Louis to Seattle on a daily basis.

  • Which is the best airline for flights from St. Louis to Seattle, Alaska Airlines or Southwest?

    The two airlines most popular with KAYAK users for flights from St. Louis to Seattle are Alaska Airlines and Southwest. With an average price for the route of $393 and an overall rating of 8.0, Alaska Airlines is the most popular choice. Southwest is also a great choice for the route, with an average price of $386 and an overall rating of 8.0.

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

    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 Seattle.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Seattle from St. Louis 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 Seattle?

    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 to Seattle with an airline and back to St. Louis with another airline. Booking your flights between St. Louis and SEA can sometimes prove cheaper using this method.

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

    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 to Seattle from St. Louis up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

KAYAK’s top tips for finding a cheap flight from St. Louis to Seattle

  • Looking for a cheap flight? 25% of our users found flights on this route for $169 or less one-way and $327 or less round-trip.
  • If you’re looking for a way to cut down on the cost of tickets, consider booking connecting flights instead of a direct one. More often than not, airlines will charge lower prices for connecting flights on the same route.
  • While booking your flight, pay close attention to the in-flight services provided. This is because different flights will have varying services available even when they are facilitated by the same airline.
  • If you’re traveling with the kids, you’ll be happy to learn that Seattle Tacoma International Airport (SEA) has a child play area where the kids can play around as you clear with baggage claim. It is located on Concourse D next to Qdoba.
  • St Louis Lambert International Airport (STL) is a pet-friendly airport. If you’re traveling with a service animal or pet, there are multiple relief areas for the four-legged friends. You’ll find two on Concourse E close to Gate E4 while the other one is found on Concourse C near Gate C24.
  • If you need a private space to nurse your child at Seattle Airport, you should check out the nursing pods on Concourse A, near Gate A10E.

Prefer to fly direct from St. Louis to Seattle?

 
Direct data is based off flight results for the next 60 days. Find direct flights from all airlines flying direct from Lambert-St Louis to Seattle/Tacoma Intl.
Find which airlines fly direct from Lambert-St Louis Airport to Seattle/Tacoma Intl Airport, which days they fly and book direct flights.

Direct departures

Lambert-St Louis to Seattle/Tacoma Intl

Monday

Alaska Airlines

Alaska Airlines

Tuesday

Alaska Airlines

Alaska Airlines

Wednesday

Alaska Airlines

Alaska Airlines

Thursday

Alaska Airlines

Alaska Airlines

Friday

Alaska Airlines

Alaska Airlines

Saturday

Alaska Airlines

Alaska Airlines

Sunday

Alaska Airlines

Alaska Airlines

See more direct flights

Direct returns

Seattle/Tacoma Intl to Lambert-St Louis

Monday

Alaska Airlines

Alaska Airlines

Tuesday

Alaska Airlines

Alaska Airlines

Wednesday

Alaska Airlines

Alaska Airlines

Thursday

Alaska Airlines

Alaska Airlines

Friday

Alaska Airlines

Alaska Airlines

Saturday

Alaska Airlines

Alaska Airlines

Sunday

Alaska Airlines

Alaska Airlines

See more direct flights

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

 
See real verified KAYAK customer reviews for airlines flying from St. Louis to Seattle. 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 Seattle? 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
7.8Comfort
7.1Food
8.5Crew
8.1Boarding
7.0Entertainment
Airline reviews

My flight was delayed 2 hours which led me to lose my connection. As a consequence, I had to spend hours changing flights and hotel reservations to arrange my arrival to Vancouver.

2.0 MediocreAnonymous, Sep 2025BWI - SEA
Read more Alaska Airlines reviews

My flight was delayed 2 hours which led me to lose my connection. As a consequence, I had to spend hours changing flights and hotel reservations to arrange my arrival to Vancouver.

No Free Wifi and the flight was a tad late.

The plane was clean. They got us to the destination. It was very difficult to hear the announcements at the gate. The person was speaking way too quickly, and the sound system did not carry to all parts of the seating area at the gate. The flight left more than an hour late, which left many of the passengers missing connections.

The flights left both airports on schedule. The flight from Idaho Falls to Seattle was a typical commuter trip. The flight from Seattle to Maui was not good: It was too long for a flight in a single-aisle plane and too cramped. I kept asking myself if I would ever visit Maui again if airlines continue to run this long flight like a typical short commuter flight. I am not looking forward to the trip home.

The chicken salad was very small, the lettuce was wilted and there was no flavor. The hamburger was excellent.

Mid flight we were bothered by a bee. Kind of odd, but a bee allergy made it a bit stressful. Attendants passed by our aisle during service multiple times. Otherwise, it was fine.

5 1/2 hour flight with no food service or options is inexcusable.

Mostly good. Delayed which in my experience so far happens often with Alaska Airlines. Thank you.

Excellent overall, but had to wait 30 months while taxiing. In fact, I’m still on the plane now!

We received a check-in reminder the day before the flight, and it listed the flight at a later time. Correct flight number, same seats, etc. for 3 hours later. I called the airline to confirm and they had no record of the email. The info was wrong, and we would have missed our flight if we'd assumed it was correct. I want to know where/how we received this incorrect info.

I wish they had movie screens in the headrests. The seats are much improved, more legroom and recently renovated. Bathroom was clean. Staff was outstanding!!

As always, the entire Southwest experience was wonderful, from online booking to flight to baggage retrieval. Very grateful.

The weather could have been better. There was a 40 minute ATC delay in SFO because of marine fog and a micro cell storm delayed landing and take-off at Nashville. The gate was changed 5 minutes from boarding from gate B3 to gate C23 at Nashville airport.

After being assaulted by a flight attendant I was then brushed off as oh well because he long braids didn’t mean to whip me in the eye. I have filed complaints and will see. But like any other issue I’ve had with kayak involved it’s been trash. Last time I’ll be using your app

AC sub par. WiFi not working correctly. Ac sucked. Seats very narrow.

Near 4 hour flight with only 1 service. Had to use call button to request water. Internet and power not working until into flight. Internet would stop working during flight.

Southwest's seats are the least comfortable I have ever sat in.

The cabin was quiet for the redeye flight. The area was clean. The staff was great. The 787 Max was in good condition. Drawbacks were that the seat widths were tight for some passengers. The seat padding was at best average and for a long flight uncomfortable.

Southwest like most American domestic airlines, is a mediocre airline. But it is among the cheapest. Oh well.

My flight was delayed 50 minutes and we were rushed to board to then sit for 15 minutes until the pilot arrived. Unacceptable since we could have waited to board. Also the delayed flight was updated AFTER we boarded to more than the 10 minutes as originally stated.

Perfect flight both ways. On time, courteous staff, plane comfortable and cool. Best domestic flights I’ve had in awhile.

Really low quality food especially for an international flight. The crew also was surprisingly unpleasant except couple of ladies. I know we were not in first class but that’s no reason to treat customers as less.

Flight delayed for two and half hours and then canceled altogether due to mechanical issues. No mechanic onsite to fix so had to send one from LAX.

Crew was good. The reservation got mixed up and they didn't have my TSA number. I am also a Silver Medallion and wasn't able to use Sky Priority.

Delta made it easy, comfortable and timely. The crew was fantastic.

This route with Delta always has delays or is cancelled. Aircrafts seem smaller and older. I fly Delta quite a bit - haven’t had issues with the international flights. But this route has always been the troublesome one

Three seats in first class were broken and while they were able to still acommodate us it was looking very touch and go and they had others they could not acommodate

Great flight with Delta! Boarding was quick and easy, the amenities were solid, and the plane was in great shape. The flight attendants had a fun, lively energy while staying professional. All in all, a smooth trip — even managed to catch up on some rest. Thanks, Delta!

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

They we able to seat my companion and I next to each other. Plane’s temperature was very cool. Willl be more prepared on return trip.

All was good and they were able to seat my travel companion next to me. Thank you.

Like the ample leg room. May as well not bother with snacks if it's only a two ounce bag of pretzels. Didn't use the entertainment option. Was there one?

What an amazing flight. I haven’t experienced this level of service in a flight in years. This will be the only way to fly to Hawaii for me in the future.

Kayak sold me a ticket after check in time. Could not check in. Could not get on flight.

Love you guys are so friendly and kind and wonderful

Agents talk too fast over intercom. I know it’s memorized and we’ve all heard it before. Just slow down a little. Stop charging for checked bags. I was pleased to get my bags promptly at each end of my flight.

Everything was great except having to check in at Alaska. That was a surprise and took extra time and effort. Should have been explained somewhere maybe on the HA electronic ticket.

It was clean and the crew was great. I wish the chairs could recline just a little more and you would provide small pillows for people with bad backs. My back is fused and a little support would be great.

I accidentally made this purchase and they wouldn’t refund me even though I called immediately to cancel it.

Given it’s a red-eye into Charolotte, we didn’t get any food. The survey does not include “N/A” so the rating will be skewed.

Great. Quick and quiet and east. The breakfast choices were a welcome surprise!

American airlines suck they delay the flights all the time made me sleep in an airport because my flight was delayed and I miss my connecting flight

There's nothing I liked about it. For first off I scheduled this trip two weeks in advance then they delayed my flight which messed up my whole trip. So I scheduled it for the following weekend thinking there won't be a delay and guess what as soon as I got to the airport we said in the airplane on the tarmac for an hour and a half. Not only was it delayed I missed my connecting flight meaning I had to stay the night at Dallas-Fort Worth airport sleeping on the floor. I will tell you this I will never fly American airlines ever again I have had nothing but horrible experience with them and I just throw money at them

The stewardess hit me with the food kart twice on the head and didn't say I'm sorry once. The same stewardess gave me a warm Apple Juice with No ice. The Flight was delayed for Departure 6 times, starting from 2:36pm, finally taking off 7:50pm. I was late picking up my child from the sitter by 3 hours.

Having to reschedule flights a day later, they loaded by luggage on the wrong plane from Little rock now I have to HOPE they deliver it to where im staying like they said would. International flight crew was very disgruntled and not very friendly.

We will be writing a long, detailed letter to corporate about our awful experience with American airlines.

It took way too long to diagnose and solve the problem of a broken crew member cabin seat. Though compensation for the volunteer who left the flight was very kind.

The entertainment package was vast and the selections were very current. Keep updating it was great.

The seat was so hard my tailbone was aching The crew was kind of a b**** because I made a joke that I didn't care if they close the door I total c*** when she was trying to f****** act like she was mad at me because I said that The flight was bumpy. Sure you didnt have control over that.

Everything you need to know for your flight from St. Louis to Seattle

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