STL - SEA

$74 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 2/27. 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, 0 bags

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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Everything you should know

Cheapest round-trip
$162
Overall average: $299
Southwest
Sat 2/28Sat 3/7
STL - SEA • 1 stop
Cheapest non-stop
$177
Typical prices: $300-$453
Alaska Airlines
Tue 4/28Sat 5/2
STL - SEA • Non-stop
Our travelers' advice
AI-powered summary based on content written by travel experts. AI can make mistakes.
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
Video guide: How to find cheap flights to Seattle
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Top airlines
Southwest
Cheapest • from $162 (round-trip)
Alaska Airlines
Best reviews • 8.0 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
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 • 27% price drop
July
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
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We hope you love your trip to Seattle!
Flight Deals
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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

Sat, Feb 28 - Sat, Mar 7
Southwest Logo
6:10 am - 1:50 pm
STL
-
SEA
9h 40m
1 stop
Southwest Logo
10:30 am - 1:55 am
SEA
-
STL
13h 25m
1 stop
$162Southwest
Mon, Feb 23 - Wed, Feb 25
American Airlines Logo
6:36 pm - 12:24 am
STL
-
SEA
7h 48m
1 stop
American Airlines Logo
6:44 am - 3:28 pm
SEA
-
STL
6h 44m
1 stop
$168American Airlines
Fri, Feb 27 - Tue, Mar 3
Frontier Logo
1:59 pm - 12:01 pm
STL
-
SEA
24h 02m
1 stop
Frontier Logo
7:33 pm - 3:53 pm
SEA
-
STL
18h 20m
2 stops
$172Frontier
Fri, Feb 27 - Fri, Mar 6
Frontier Logo
1:59 pm - 12:01 pm
STL
-
SEA
24h 02m
1 stop
Frontier Logo
12:24 pm - 9:49 am
SEA
-
STL
19h 25m
1 stop
$174Frontier
Tue, Apr 28 - Wed, May 13
Delta Logo
6:45 pm - 11:59 pm
STL
-
SEA
7h 14m
1 stop
Delta Logo
6:05 am - 4:45 pm
SEA
-
STL
8h 40m
1 stop
$177Delta
Mon, Feb 23 - Mon, Mar 2
Frontier Logo
10:11 pm - 10:54 am
STL
-
SEA
14h 43m
1 stop
Frontier Logo
12:30 pm - 6:51 am
SEA
-
STL
40h 21m
2 stops
$181Frontier
Sat, Mar 7 - Mon, Mar 9
American Airlines Logo
6:36 pm - 12:24 am
STL
-
SEA
7h 48m
1 stop
American Airlines Logo
12:13 am - 8:51 am
SEA
-
STL
6h 38m
1 stop
$184American Airlines
Sat, Feb 28 - Sat, Mar 7
Hawaiian Airlines Logo
2:47 pm - 5:26 pm
STL
-
SEA
4h 39mnonstop
Hawaiian Airlines Logo
7:55 am - 1:51 pm
SEA
-
STL
3h 56mnonstop
$186Hawaiian Airlines
Wed, Feb 25 - Sat, Feb 28
American Airlines Logo
7:58 am - 1:42 pm
STL
-
SEA
7h 44m
1 stop
American Airlines Logo
12:07 am - 8:35 am
SEA
-
STL
6h 28m
1 stop
$193American Airlines
Tue, Apr 21 - Sat, Apr 25
Alaska Airlines Logo
7:00 am - 9:35 am
STL
-
SEA
4h 35mnonstop
Alaska Airlines Logo
5:57 pm - 11:59 pm
SEA
-
STL
4h 02mnonstop
$197Alaska Airlines
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.

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 $249 (return) on average. On the other hand, the most expensive months are July and June, where the average cost of round-trip tickets is $431 and $417 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.

Yes, flying with a layover may cost you more time, but you can also save money on the route, with a 1 stop layover the cheapest option at $302 on average.

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.

Expert advice

Expert advice for your flight from St. Louis to Seattle

 
AI-powered summary based on content written by travel experts. AI can make mistakes.
KAYAK teamed up with top travel experts to share the best tips for your journey.
Our travel experts
Yulia Denisyuk

Yulia Denisyuk

Expert on STL

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.

Harriet Baskas

Harriet Baskas

Expert on SEA

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.

Good to know

Low seasonJanuary
Cheapest flight$74
Best time to beat the crowds but there is an average 12% increase 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 $74 for a one-way ticket and $162 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, American Airlines, Delta, United Airlines, Lufthansa, and Hawaiian Airlines.

  • 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?

    Star Alliance, SkyTeam, and oneworld are the airline alliances operating flights between St. Louis and Seattle, with Star Alliance being the most commonly used for this route.

  • 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 $378 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 $381 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 $214 or less one-way and $295 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 11819 reviews
7.0Entertainment
8.5Crew
8.1Boarding
7.8Comfort
7.1Food
Airline reviews

I had to cancel my trip due to health reasons three days after making the reservation. I was stunned to find out that the ticket was not able to be credited for future travel. $734 loss. Not happy that this was not my experience with Southwest Airlines. I will stick with SW in the future. Boo Alaskan Air and Kayak.

2.0 MediocrePATRICIA, Jan 2026
EAT - SEA
Read more Alaska Airlines reviews

I had to cancel my trip due to health reasons three days after making the reservation. I was stunned to find out that the ticket was not able to be credited for future travel. $734 loss. Not happy that this was not my experience with Southwest Airlines. I will stick with SW in the future. Boo Alaskan Air and Kayak.

The staff was extremely helpful and accommodating. The only thing I could have done without was the long layover in between flights but I was going to a less popular destination so it was understandable.

All went well, right on time, easy boarding. We ordered the evergreens grain bowl and were surprised and pleased how adequate it was for vegan lunch! Landing was smooth and gate exit was easy

My seat and tray were filthy. Someone’s used straw was in the seat pocket and there were coffee stains and food crumbs on the tray table

On time, good boarding process very quick. Clean planes. Planes are tight, not much leg room ( i am only 5'8"). Some attendants are moving through aisles fiercely and pushing passengers. Got yelled for a tiny man bag that it is an extra personal tem ( size of a wallet) Wi-Fi on the plane does not work well with android phones.

I didn’t go, and can’t use a no refundable ticket.

good food and service and the seats were much better than anything comparable provided by US airlines. The entire experience was light years better than flying with a US company.

On time departure and early arrival giving more than ample time for connecting flight.

Flights were on time, easy boarding, comfort, flight was smooth.... Best travel experience I have ever had

Second flight in a row that I've been on where the auto bag counter stopped working and they had to manually count cargo before takeoff. Also second flight where my whole fruit and cheese plate looked pretty stale/old. The grapes were very strange tasting to the point where I didn't eat them. Apple slices were just sad/gross looking so also avoided those.

All good except once again bags took an hour at Midway Airport Happens all the time. Ridiculous

Everything went smoothly and we even arrived a little bit early.

Great vacation. Can't wait till next year for another one.

Great flight but super high price. Glad it was a business trip and not personal

On time. Friendly staff. Took to long to pre bord all the specialty groups. Cramped small plane

The seats were comfortable, and the boarding process was pretty smooth.

3 hour delay. Had to change plans and was still delayed.

The staff was very friendly, professional, and courteous. The overall flight was a great experience.

The crew canceled the complementary snack and drink in anticipation of turbulence that never materialized. I was counting on the drink (water) to take the the doses of medication - prescribed for my heart condition - that were due during the flight. Since no snack or meal was served on this flight, I cannot rate the food quality. Otherwise, this flight was excellent.

Departure was delayed more than 1/2 hour while we waited for luggage (only) transfer from another flight/plane. Once approved for takeoff, the flight was excellent.

I didn't take this flight. I changed the flight. Why am I getting surveys and notifications on flights that I change. Seems like a defect with Kayak.

Delta One is extraordinary. I fly business when somebody hires me. I just wonder why there is such a chasm between business class and the insanely inhumane and nonsensical coach. The seats are not large enough to fit even my tiny wife. We fly 10% of what we did because we don’t want to pay 5-10 k but for $400 it’s unbearable. It seems like the accountants took over and made stupid decisions. Screw in 20 extra seats and make it so unbearable that people fly 90% less. Just put the damn price up and put some proper chairs in. But business, yay.

Timing, quality of service, promptness and courtesy of the staff

It was last minute due to weather - considering - it was amazing! Good smiles, friendly staff and they were making sure we knew what was going on when and where.

delta last minute gave me a boarding pass for a different flight with no confirmation that they were changing it

Staff was great! Kind and cordial! Middle seat row 28 seat B has a hump in it. Trays were getting stuck when putting down and up. Good flight

This flight was no comparison to our prior flight. I'm thinking it all has to do with the age of the aircraft.

2 of the seats in row 31 the entertainment system was not working, and one seat the tray table did not go all the way down. Flight arrived early and departed on time which was great.

DELTA does a terrific job making sure you are well taken care of during the flight, gives you assurance before the flight through numerous email notifications about your upcoming flight & lastly good follow up after the flight making sure your needs were mat. It has been, is & will continue to be my carrier of choice in all my future travels. Good Job DELTA

The customer service before board was very rude and when I expressed my concerns about making the connecting flight she laughed and told me I bought the wrong ticket. I explained once it showed the flight was delayed it no longer let me change seats or anything. I was trying to upgrade to make sure I would get to the next gate on time.

Yall need to integrate your system with Alaska more efficiently. They booted me off the first flight because of a discrepancy on your end.

The crew at Hawaiian Airlines was fantastic. Kind and hard working. The pilots were great with giving us all the updates to make sure we were informed.

Very good. Nice plane and we sat in economy plus - bigger seats, more room. They served a meal and snacks, and the meal was an apple stuffed pancake that was very good! The snack for us was a hummus sandwich - also very good. The flight attendants were helpful and nice. They have plenty of movies and shows to watch. My only negative -- they changed our flights around and did not adjust the layovers, so we ended up with a very long and unnecessary layover in Honolulu.

I liked the Starlink WiFi but didn't like how they said they were the only airline to offer a free meal and it turns out to be just a standalone sandwich and then charge for snacks to go with it. Rather have the free snacks like Southwest, but have the option to purchase a decent meal for a 5+ hour flight.

Flight scheduled to take off at 5.55pm but it did not take off until 7pm due to some food delivery delay.

Unfortunately, I was put into the middle seat in the first row of premium seating. Sounds nice right? No! that is the worst seat in the plane. I wish I was in economy rather than be in that seat! There is no seat back pocket, no tray table, no charger. Nothing! so unless you're row mates are willing to let you share their basic amenities any flyer should have, you are stuck. It was the worst experience ever! And the flight attendant forgot to take my drink order. I felt like the forgotten flyer.

Delayed and cancelled flights were hard and very stressful, both ways!

The crew was quite good, they came by often with drinks or to collect trash. But what wasn't nice was the flight was over weigh and several people had to be rebooked. I was questioned whether I should have a seat when I was getting to it. The in-flight entertainment kept buffering and interrupting. And the route took the airplane through high winds which caused us a longer flight

Wasn’t on the flight due to Alaska cancellation…also after all the rerouting, I was going to be on a later flight that left SFO at 7:47pm, which meant an almost 6 hour layover. That same Hawaiian flight was delayed for another 2hours.

I had to cancel the flight because with a 3 hour delay for 'unexpected maintenance' in getting to LAX, I couldn't connect to an overseas flight that I had booked on Scandinavian Air.

Update to handle the delay was very bad, crews no smiles or welcome or thanks. Don’t care attitude

It would be nice to have some low carb options in the snacks.

I was trying to take 2 one and a half hour one way trips and I experienced almost 20 delays over the course of those two trips. Only a few of them were due to weather the rest was disorganization

No gates avail at DFW so our incoming had to wait 30 mins for a plane to push back because they Had mechanical. We boarded 90 mins delayed and then we had a mechanical. Come on American…do better. Also at my seat the tray table had not been cleaned. Floor had not been cleaned. But captain and flight Att were very picture and apologetic.

Crew was helpful and cheerful especially when they had no refreshments to work with. The plane was never serviced and had nothing but limited water and coffee onboard. For the price point, a concern of services.

Flight was smooth, quick and felt safe. The 2 delays not happening would have been better but I guess that happens in the airline industry

Flight was canceled. I asked to be rerouted to OKC and then took an Uber.

AA did not allow to board a flight because my connecting flight from DFW had been canceled. I got on another flight to another city. No service on the plane and I did not use their entertainment system.

On time on a day with lots of weather cancellations on other flights. Thank you for getting me home during a winter storm!

Don't change gate multiple times make people run across the airport. Announce delays in a timely manner. Have maintenance crew ready. Don't delay and keep passengers on the plane for 3 hrs. on tarmac.

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

Information on your arrival and departure airports