SEA - STL

$64 Find Cheap Flights from Seattle to St. Louis - Compare and Save

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Seattle to St. Louis departing on 11/7. 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

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Everything you should know

Cheapest round-trip
$293
Typical prices: $270-$477
Southwest
Mon 10/5Thu 10/29
SEA - STL • 1 stop
Cheapest non-stop
$297
Typical prices: $249-$464
Southwest
Fri 9/25Sun 9/27
SEA - STL • Non-stop
Advice from real travelers
AI-powered summary based on content written by travel experts and KAYAK users. AI can make mistakes.
At Seattle, Alaska’s self check-in can save time; arrive early for this route.
On Alaska, measure carry-on wheels carefully or you may pay to check bags.
Expert advice
Expert advice
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Expert advice
Expert advice
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Nonstop flights
Every day
You can fly direct with Alaska Airlines and Southwest. Average duration is 3h 55m
Direct flights
Direct flights
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Direct flights
Direct flights
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Top layover airports
Dallas (DFW)
Cheapest • Avg $249 (round-trip)
Salt Lake City (SLC)
Shortest trip • 6h 46m (one-way)
Insights
Insights
Insights
Insights
When to book
3 weeks
in advance
Our data shows that travelers who book at least 3 weeks in advance save around 38% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
January
Cheapest • 42% price drop
May
Most popular
Good to know
Good to know
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Good to know
Good to know
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We hope you love your trip to St. Louis!
Flight Deals
Booking Insights
Expert advice
Flight Deals

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

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

Mon, Oct 5 - Thu, Oct 29
Southwest Logo
8:40 pm - 11:40 am
SEA
-
STL
13h 00m
1 stop
Southwest Logo
2:25 pm - 10:30 pm
STL
-
SEA
10h 05m
2 stops
$293Southwest
Mon, Sep 28 - Thu, Oct 1
Southwest Logo
1:25 pm - 12:40 am
SEA
-
STL
9h 15m
2 stops
Southwest Logo
8:35 am - 6:10 pm
STL
-
SEA
11h 35m
1 stop
$293Southwest
Sun, Aug 16 - Mon, Aug 24
Frontier Logo
8:53 pm - 6:15 pm
SEA
-
STL
19h 22m
1 stop
Frontier Logo
7:58 pm - 9:19 am
STL
-
SEA
15h 21m
1 stop
$294Frontier
Tue, Oct 6 - Tue, Oct 27
Frontier Logo
4:27 pm - 7:17 pm
SEA
-
STL
24h 50m
1 stop
Frontier Logo
10:35 am - 9:51 am
STL
-
SEA
25h 16m
2 stops
$295Frontier
Fri, Nov 13 - Thu, Dec 3
Delta Logo
11:47 pm - 10:39 am
SEA
-
STL
8h 52m
1 stop
Delta Logo
7:10 am - 2:44 pm
STL
-
SEA
9h 34m
1 stop
$302Delta
Fri, Nov 13 - Fri, Dec 4
Delta Logo
11:47 pm - 10:39 am
SEA
-
STL
8h 52m
1 stop
Delta Logo
3:20 pm - 8:46 pm
STL
-
SEA
7h 26m
1 stop
$302Delta
Wed, Nov 18 - Wed, Dec 2
American Airlines Logo
6:12 am - 4:43 pm
SEA
-
STL
8h 31m
1 stop
American Airlines Logo
9:30 am - 2:55 pm
STL
-
SEA
7h 25m
1 stop
$307American Airlines
Tue, Sep 8 - Fri, Sep 11
Multiple Airlines Logo
8:13 am - 2:21 pm
SEA
-
STL
4h 08mnonstop
Multiple Airlines Logo
12:17 pm - 6:28 pm
STL
-
SEA
8h 11m
1 stop
$313Multiple Airlines
Mon, Oct 5 - Tue, Oct 27
Multiple Airlines Logo
9:45 pm - 11:32 am
SEA
-
STL
11h 47m
1 stop
Multiple Airlines Logo
7:02 am - 9:35 am
STL
-
SEA
4h 33mnonstop
$318Multiple Airlines
Wed, Sep 16 - Mon, Sep 21
American Airlines Logo
12:35 pm - 6:38 pm
SEA
-
STL
4h 03mnonstop
American Airlines Logo
5:00 am - 10:09 am
STL
-
SEA
7h 09m
1 stop
$352American Airlines
Booking Insights

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

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

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

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from Seattle to St. Louis departing in September.

Flight prices are below average for this route right now.

Flights to St. Louis from Seattle usually cost between $294 and $568 in September.
The lowest price found in the past 5 days was $293 on Southwest (Sep 28-Oct 1).

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

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

If you are looking for a flight deal from Seattle to St. Louis, look for departures on Tuesdays and avoid leaving on a Sunday, as it's usually the priciest day. When flying back from St. Louis, Friday is the cheapest day to fly and Monday is the most expensive.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Seattle to St. Louis, 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 Seattle to St. Louis is January, where tickets cost $237 (return) on average. On the other hand, the most expensive months are December and July, where the average cost of round-trip tickets is $535 and $507 respectively.

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

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 $507 on average.

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

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Seattle to St. Louis, 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 Seattle to St. Louis, you should book around 3 weeks before departure, which saves you about 38% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 18 weeks before departure.

Find deals
Expert advice

Expert advice for your flight from Seattle to St. Louis

 
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.

Read more
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.

Read more

Good to know

Low season

January

Cheapest flight

$64
Best time to beat the crowds with an average 42% drop in price.
Most popular time to fly with an average 4% increase in price.
Flight from Seattle to St. Louis

When to book flights from Seattle to St. Louis

Are your dates flexible? Find out the best times to travel from Seattle to St. Louis 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.

Flights from Seattle to St. Louis: the best tips from KAYAK users' own experiences

Insights shared by verified travelers who flew the route from Seattle to St. Louis 
Learn how KAYAK collects reviews and tips from users.
Verified travelerFlew with Alaska Airlines
SEA
-
STL
Jul 2025
Give yourself extra time. Love the self check in options.
Verified travelerFlew with Alaska Airlines
SEA
-
STL
Feb 2024
Be sure to measure your wheels for carry on my luggage was the correct size but the wheels made it over so had to check my bag wasn't happy about that since you have to pay for checked should at least get one free.

FAQs for booking flights from Seattle to St. Louis

  • Where can I find car rentals from St. Louis Lambert International Airport (STL)?

    The use of car rentals is one of the most efficient methods of connecting travelers from STL Airport to the city center and St. Louis downtown. Car Rental Town-Saint Louis Airport is one car rental agency that provides affordable services to travelers arriving at STL Airport in St. Louis. This agency is located in STL Airport, along terminal 1.

  • How can I connect to St. Louis downtown from STL Airport?

    The use of the Metrolink bus system is the most efficient and inexpensive method of connecting travelers to St. Louis downtown from STL Airport. Travelers connecting to St. Louis downtown from STL Airport pay approximately $4.00 on Metrolink buses. Apart from buses, travelers can also use rental cars to connect to St. Louis downtown from STL Airport. Consider renting a car at Car Rental Town-Saint Louis Airport Agency.

  • Are there kid-friendly amenities on flights from Seattle to St. Louis?

    The availability of on-demand kid-friendly entertainment options on American Airlines makes it the most preferred airline for travelers flying from Seattle to St. Louis in the company of their kids. This airline offers free in-flight WI-FI services, which allows your kids to stream their favorite video games, TV shows, and music albums, eliminating boredom.

  • Which hotel can I stay in from STL Airport in St. Louis?

    There are several hotels where travelers landing at STL Airport can stay. One hotel that is easily accessible to travelers from STL Airport is the Quality Inn Airport. This hotel is located along Natural Bridge Rd, St. Louis, and it provides free airport shuttle services to customers.

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

    In the last 5 days, the lowest price for a flight from Seattle to St. Louis was $64 for a one-way ticket and $293 for a round-trip.

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

    Even though you are not required to have a passport, keep in mind that an official ID is needed to board the airplane.

  • Which airports will I be using when flying from Seattle to St. Louis?

    On your way to St. Louis, you’ll fly out from Seattle/Tacoma Intl. You’ll be landing at Lambert-St Louis.

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

    Alaska Airlines, JetBlue, Delta, and Hawaiian Airlines offer inflight Wi-Fi service on the Seattle to St. Louis flight route.

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

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

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

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

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

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

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

    The two airlines most popular with KAYAK users for flights from Seattle to St. Louis are Southwest and Alaska Airlines. With an average price for the route of $387 and an overall rating of 8.0, Southwest is the most popular choice. Alaska Airlines is also a great choice for the route, with an average price of $447 and an overall rating of 7.9.

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

    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 Seattle to St. Louis.

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

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

    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 St. Louis with an airline and back to Seattle with another airline. Booking your flights between Seattle and STL 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 Seattle to St. Louis?

    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 St. Louis from Seattle 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 Seattle to St. Louis

  • Looking for a cheap flight? 25% of our users found flights on this route for $278 or less one-way and $442 or less round-trip.
  • Despite having other airports that serve similar flights from Seattle to St. Louis, like Renton Municipal Airport and King County International Airport, travelers from Seattle prefer using Seattle-Tacoma International Airport (SEA) as their departure airport to St. Louis. This airport is widely preferred due to the availability of several cheaper means of transport that connect travelers from the city center and Seattle downtown to the airport, such as taxis, buses, and airport shuttles.
  • Travelers who plan to catch the earliest flight that departs SEA Airport for St. Louis should consider spending their night in a nearby hotel. One hotel that guarantees travelers quick access to SEA Airport is the DoubleTree by Hilton Hotel Seattle Airport. This hotel is located along International Blvd, Seattle, a 4min drive from SEA Airport and offers airport shuttle services.
  • Are you planning to travel from Seattle to St. Louis in the company of a person with reduced mobility? Worry no more. SEA Airport offers curb-to-aircraft services to persons with reduced mobility. All airlines serving flights from SEA Airport to St. Louis, like American Airlines, Qatar Airways, and Southwest, have deployed personnel across the airport to assist persons with reduced mobility.
  • Travelers who wish to shop before taking a flight from Seattle to St. Louis shouldn’t get worried. SeaTac Shopping Mall is one shopping mall that offers quality and affordable products to travelers flying from SEA Airport in Seattle. This shopping mall is located along International Blvd, SeaTac, just a walking distance from SEA Airport.
  • If you plan to take care of your stomach and have some rest as you wait for your flight from SEA Airport to St. Louis, consider visiting Dish D'lish Restaurant. Dish D'lish is one restaurant that offers the best food at an affordable price to travelers at SEA Airport as they wait for their flights to St. Louis.

Prefer to fly direct from Seattle to St. Louis?

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

Direct departures

Seattle/Tacoma Intl to Lambert-St Louis

Monday

Alaska Airlines,Southwest

Alaska Airlines,Southwest

Tuesday

Alaska Airlines

Alaska Airlines

Wednesday

Alaska Airlines

Alaska Airlines

Thursday

Alaska Airlines,Southwest

Alaska Airlines,Southwest

Friday

Alaska Airlines,Southwest

Alaska Airlines,Southwest

Saturday

Alaska Airlines,Southwest

Alaska Airlines,Southwest

Sunday

Alaska Airlines,Southwest

Alaska Airlines,Southwest

See more direct flights

Direct returns

Lambert-St Louis to Seattle/Tacoma Intl

Monday

Alaska Airlines,Southwest

Alaska Airlines,Southwest

Tuesday

Alaska Airlines

Alaska Airlines

Wednesday

Alaska Airlines

Alaska Airlines

Thursday

Alaska Airlines,Southwest

Alaska Airlines,Southwest

Friday

Alaska Airlines,Southwest

Alaska Airlines,Southwest

Saturday

Alaska Airlines,Southwest

Alaska Airlines,Southwest

Sunday

Alaska Airlines,Southwest

Alaska Airlines,Southwest

See more direct flights

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

Information on your arrival and departure airports

Seattle (SEA)
St. Louis (STL)