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$156+ Cheap flights from Seattle to St. Louis (SEA - STL)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 8/18. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — STL
Jul 27 — Aug 31
Mon 7/27
Mon 8/3
1 adult, Economy
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Find cheap flights from Seattle to St. Louis with Cheapflights

1. Tell us where you want to go

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Cheapflights Tip: The best prices from Seattle/Tacoma Intl to Lambert-St Louis are usually found in January or February, booked 77 days in advance, depart on a Tuesday or Thursday and return on a Thursday

Cheap flight deals from Seattle to St. Louis

Cheapest flights from Seattle to St. Louis
Explore the most affordable flight options available from Seattle to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on June 27, 2026.

This CheapOair deal was found by Cheapflights users on 6/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 6/278:12 pm
SEA
-
STL
1 stop15h 54m
Frontier
Sun 6/287:38 pm
STL
-
SEA
1 stop16h 10m
Frontier
Deal found 6/26$374
This Kiwi.com deal was found by Cheapflights users on 6/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/161:06 pm
SEA
-
STL
Nonstop3h 51m
Multiple Airlines
Sat 7/188:08 pm
STL
-
SEA
1 stop15h 09m
Multiple Airlines
Deal found 6/25$376
This Delta deal was found by Cheapflights users on 6/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/711:05 pm
SEA
-
STL
1 stop8h 31m
Delta
Sat 10/107:55 pm
STL
-
SEA
1 stop6h 16m
Delta
Deal found 6/22$377
This Kiwi.com deal was found by Cheapflights users on 6/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/86:00 pm
SEA
-
STL
Nonstop3h 59m
Multiple Airlines
Sat 10/178:10 pm
STL
-
SEA
1 stop15h 41m
Multiple Airlines
Deal found 6/23$378
This United Airlines deal was found by Cheapflights users on 6/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/812:00 pm
SEA
-
STL
1 stop8h 30m
United Airlines
Fri 10/98:00 am
STL
-
SEA
1 stop10h 06m
United Airlines
Deal found 6/22$379
This KAYAK deal was found by Cheapflights users on 6/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/31:59 pm
SEA
-
STL
1 stop6h 30m
American Airlines
Thu 11/57:00 am
STL
-
SEA
1 stop9h 59m
American Airlines
Deal found 6/23$380
This Booking.com deal was found by Cheapflights users on 6/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 7/138:53 pm
SEA
-
STL
1 stop19h 12m
Multiple Airlines
Thu 7/166:02 am
STL
-
SEA
Nonstop4h 28m
Multiple Airlines
Deal found 6/22$381
This Southwest deal was found by Cheapflights users on 6/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/1312:15 am
SEA
-
STL
1 stop6h 45m
Southwest
Sat 10/176:35 am
STL
-
SEA
2 stops9h 55m
Southwest
Deal found 6/24$382
This United Airlines deal was found by Cheapflights users on 6/26. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/187:00 am
SEA
-
STL
1 stop6h 38m
United Airlines
Tue 8/251:36 pm
STL
-
SEA
2 stops9h 07m
United Airlines
Deal found 6/26$383
This United Airlines deal was found by Cheapflights users on 6/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/257:11 am
SEA
-
STL
2 stops11h 35m
United Airlines
Sun 8/305:10 am
STL
-
SEA
1 stop6h 51m
United Airlines
Deal found 6/23$384
This Kiwi.com deal was found by Cheapflights users on 6/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/226:04 pm
SEA
-
STL
Nonstop3h 55m
Multiple Airlines
Sat 7/258:08 pm
STL
-
SEA
1 stop15h 09m
Multiple Airlines
Deal found 6/24$385
This Kiwi.com deal was found by Cheapflights users on 6/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/2812:35 pm
SEA
-
STL
2 stops18h 22m
Frontier
Fri 7/318:08 pm
STL
-
SEA
1 stop15h 09m
Frontier
Deal found 6/22$386

Find flight deals from Seattle to St. Louis

Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) to St. Louis (STL). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated June 27, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$376
(Kiwi.com)

One-way from

$156
(Kiwi.com)

Popular in

December

Cheapest in

January

Average price

$491

Good round-trip deal

$437 or less

Good one-way deal

$278 or less
Provider with most accurate pricing for Seattle/Tacoma Intl-Lambert-St Louis flight deals.
Search Deals
Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-Lambert-St Louis flights.
Search Deals
From Seattle/Tacoma Intl to Lambert-St Louis
Search Deals
One-way flight from Seattle/Tacoma Intl to Lambert-St Louis
Search Deals
High demand for flights, 1% potential price rise
Search Deals
Cheapest flight prices on average. 3% potential price decrease ($14 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in June 2026
Search Deals
Price to beat on a round-trip flight from Seattle/Tacoma Intl to Lambert-St Louis.
Search Deals
Price to beat on a one-way flight from Seattle/Tacoma Intl to Lambert-St Louis.
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Seattle to St. Louis that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated June 27, 2026.
Use the filters below to find and compare flights from Seattle to St. Louis that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Fri 10/16

6:00 pm-11:59 pm

Nonstop3h 59m

Lambert-St Louis

Tue 10/20

7:00 am-9:35 am

Nonstop4h 35m

$377

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Sun 9/20

7:00 am-3:38 pm

1 stop6h 38m

Lambert-St Louis

Sat 9/26

9:00 am-9:01 pm

2 stops14h 01m

$384

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Tue 9/22

11:03 am-10:00 pm

2 stops8h 57m

Lambert-St Louis

Wed 9/23

9:43 am-4:07 pm

1 stop8h 24m

$384

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Fri 7/10

11:49 pm-10:07 am

1 stop8h 18m

Lambert-St Louis

Tue 7/14

7:23 pm-1:13 am

1 stop7h 50m

$393

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Wed 7/22

7:30 am-6:40 pm

2 stops9h 10m

Lambert-St Louis

Sat 7/25

4:40 pm-12:15 am

2 stops9h 35m

$397

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Fri 10/16

6:35 am-7:05 pm

2 stops10h 30m

Lambert-St Louis

Tue 10/20

7:45 am-12:50 pm

1 stop7h 05m

$402

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Fri 7/17

6:04 pm-11:59 pm

Nonstop3h 55m

Lambert-St Louis

Tue 7/21

8:08 pm-9:17 am

1 stop15h 09m

$421

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Mon 8/24

6:15 am-8:00 pm

2 stops11h 45m

Lambert-St Louis

Thu 9/10

6:00 am-12:50 pm

2 stops8h 50m

$457
Quickest round-trip

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Fri 7/17

6:04 pm-11:59 pm

Nonstop3h 55m

Lambert-St Louis

Tue 7/21

7:56 pm-10:24 pm

Nonstop4h 28m

$466

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Fri 7/24

7:55 am-1:52 pm

Nonstop3h 57m

Lambert-St Louis

Tue 7/28

7:56 pm-10:24 pm

Nonstop4h 28m

$482

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/26

Showing 1-10 of 23 resultsSorted by cheapest first
1
2
3

Compare providers for flights from Seattle to St. Louis

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Seattle to St. Louis in June.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
CheapfaremartPrice Accuracy-Trust Score*1 star
PricelinePrice Accuracy1 starTrust Score*3 stars
Super.comPrice Accuracy-Trust Score*3 stars
CheapTicketsDealPrice Accuracy1 starTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Seattle-St. Louis flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Seattle-St. Louis flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Seattle-St. Louis flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Seattle-St. Louis flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Seattle-St. Louis flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Seattle to St. Louis

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Seattle with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

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

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

The best time to book flights from Seattle to St. Louis is 76 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

What is the cheapest month to book a flight from Seattle to St. Louis?

Currently, January is the cheapest month in which you can book a flight from Seattle to St. Louis (average of $237). Flying from Seattle to St. Louis in December is currently the most expensive (average of $535). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from SEA to STL?

Find hourly flight availability from Seattle to St. Louis. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated June 27, 2026.

When flying from Seattle to St. Louis, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

How much does it cost to fly round-trip from Seattle to St. Louis?

The best insider tips for Seattle to St. Louis flights

AI-powered summary based on content written by travel experts. AI can make mistakes.
Cheapflights partnered with top experts to bring you the best recommendations for your Seattle to St. Louis trip
Our travel experts
Taryn White

Taryn White

Expert on STL

Taryn White is a freelance travel writer, digital creator, and travel advisor who has visited nearly 100 countries and all 50 states. She’s familiar with many airports and enjoys beach hopping, boutique hotels, spa experiences, and exploring local culture. Her work has appeared in Travel + Leisure, Condé Nast Traveler, National Geographic, Smithsonian Magazine, AFAR, and more.

Read more
Brandon Schultz

Brandon Schultz

Expert on SEA

Brandon Schultz is an award-winning food and travel writer based in New York City. His work has appeared in Forbes, AAA, Thrillist, Travel + Leisure, and The Daily Meal, among many others, and he is the author of 6 books, including 3 cookbooks.

Read more

Reviews of airlines servicing St. Louis

Get insights into the airlines that provide service to St. Louis. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to St. Louis. Reviews last updated June 27, 2026.
Peruse reviews from past customers who have flown with Alaska Airlines,Southwest, andDelta from Seattle to St. Louis to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
7.9
Good
12,582 reviews

Comfort

7.8

Food

7.0

Entertainment

7.0

Overall

7.9

Crew

8.5

Boarding

8.1

Reviews

1 / 20
4.0
Okay

Anonymous,Jun 2026

SEA - RNO

There was a delay and my husband needs a wheelchair and we were moved from 1 gate to another.
Alaska Airlines
7.9
Good
12,582 reviews
Alaska Airlines
7.9
Good
12,582 reviews

Comfort

7.8

Food

7.0

Entertainment

7.0

Overall

7.9

Crew

8.5

Boarding

8.1

Reviews

1 / 20
4.0
Okay

Anonymous,Jun 2026

SEA - RNO

There was a delay and my husband needs a wheelchair and we were moved from 1 gate to another.
Southwest
7.9
Good
4,246 reviews
Alaska Airlines
7.9
Good
12,582 reviews

Comfort

7.8

Food

7.0

Entertainment

7.0

Overall

7.9

Crew

8.5

Boarding

8.1

Reviews

1 / 20
4.0
Okay

Anonymous,Jun 2026

SEA - RNO

There was a delay and my husband needs a wheelchair and we were moved from 1 gate to another.
Delta
7.8
Good
8,452 reviews
Alaska Airlines
7.9
Good
12,582 reviews

Comfort

7.8

Food

7.0

Entertainment

7.0

Overall

7.9

Crew

8.5

Boarding

8.1

Reviews

1 / 20
4.0
Okay

Anonymous,Jun 2026

SEA - RNO

There was a delay and my husband needs a wheelchair and we were moved from 1 gate to another.
Hawaiian Airlines
7.8
Good
2,826 reviews
Alaska Airlines
7.9
Good
12,582 reviews

Comfort

7.8

Food

7.0

Entertainment

7.0

Overall

7.9

Crew

8.5

Boarding

8.1

Reviews

1 / 20
4.0
Okay

Anonymous,Jun 2026

SEA - RNO

There was a delay and my husband needs a wheelchair and we were moved from 1 gate to another.
American Airlines
7.1
Good
11,778 reviews
Alaska Airlines
7.9
Good
12,582 reviews

Comfort

7.8

Food

7.0

Entertainment

7.0

Overall

7.9

Crew

8.5

Boarding

8.1

Reviews

1 / 20
4.0
Okay

Anonymous,Jun 2026

SEA - RNO

There was a delay and my husband needs a wheelchair and we were moved from 1 gate to another.

Related info for your journey

Find useful and relevant information for your journey from Seattle to St. Louis. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airports do I use to fly from Seattle to St. Louis?

    If you book a flight from Seattle to St. Louis, you will be flying from Seattle/Tacoma Intl to Lambert-St Louis. Flights to Lambert-St Louis (STL) from Seattle/Tacoma Intl (SEA) take 3h 50m for a nonstop flight. There are 7 flights from Seattle/Tacoma Intl to St. Louis per day from 7 airlines.

  • How popular is this Seattle to St. Louis flight route?

    The Seattle/Tacoma Intl to Lambert-St Louis flight path was viewed by 5 users in the past month. Keep an eye out for changes in search interest prior to high and low season.

  • How long is the flight from Seattle to St. Louis?

    Alaska Airlines and United Airlines can get you from Seattle to St. Louis in just under 3h 59m. Your travel time can differ by up to 2h 39m. Airlines will cover a distance of 1704 mi. This flight may include one or multiple stops.

  • What are the cheapest airlines flying from Seattle to St. Louis round-trip?

    Cheapflights users have booked flights from Seattle to St. Louis round-trip from $104. Other airlines that can offer you cheap pricing are Frontier, from $137, and United Airlines, from $157. These flights start at 73% lower than the current average price 3 months from now.

  • What are the cheapest airlines to fly from Seattle to St. Louis one-way?

    $74 is the cheapest one-way deal found within the past few days, from United Airlines. You may also be able to find cheap deals on Southwest and Delta, with prices starting from $84 and $88, respectively.

  • What are the most reliable airlines from Seattle to St. Louis?

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Seattle to St. Louis on time: Hawaiian Airlines (100%), Japan Airlines (92%), Qatar Airways (91%).

  • What are the cheapest flights from Seattle to St. Louis?

    The cheapest flight price from Seattle to St. Louis is $198. On average you can expect to pay $442. The most popular route, (Seattle/Tacoma Intl - Lambert-St Louis), can usually be booked for $279.

  • Can I find deals for flights from Seattle to St. Louis that include hotel bookings?

    Yes. In addition to deals on Seattle to St. Louis flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Seattle to St. Louis?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Seattle to St. Louis.

  • Can I find deals for business class flights from Seattle to St. Louis?

    Yes. Cheapflights offers flight deals from Seattle to St. Louis by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

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

    Currently, January is the cheapest month in which you can book a flight from Seattle to St. Louis (average of $237). Flying from Seattle to St. Louis in December is currently the most expensive (average of $535). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
Edwardsville
O'Fallon
Fenton
Swansea
Fairview Heights
Eureka
Maryland Heights
Collinsville
Wentzville
Glencoe
Chesterfield
Alton
Farmington

Browse thousands of different options on Cheapflights for your next trip

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Top 7 airlines flying from Seattle to St. Louis

Discover the top 7 airlines that operate flights from Seattle to St. Louis. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated June 27, 2026.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$104Average$317FlexibilityNo cancel feeOn-timeN/A
FrontierCheapest$137Average$227FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$157Average$348FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$182Average$377FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$188Average$612FlexibilityNo cancel feeOn-time71%
Hawaiian AirlinesCheapest$204Average$403FlexibilityNo cancel feeOn-time85%
Alaska AirlinesCheapest$226Average$427FlexibilityNo cancel feeOn-time75%

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