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$68+ 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 1/23. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — STL
Jan 26 — Feb 21
Mon 1/26
Mon 2/2
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

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheapflights Tip: The best prices from Seattle/Tacoma Intl to Lambert-St Louis are usually found in January or September, booked 67 days in advance, depart on a Thursday or Tuesday and return on a Tuesday

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 December 27, 2025.

This American Airlines deal was found by Cheapflights users on 12/25. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/2710:13 pmSEA - STL
1 stop8h 22mAmerican Airlines
Thu 1/16:44 pmSTL - SEA
1 stop8h 13mAmerican Airlines
Deal found 12/25$549
This Southwest deal was found by Cheapflights users on 12/24. 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.
Sat 12/2710:35 amSEA - STL
1 stop7h 20mSouthwest
Thu 1/15:25 pmSTL - SEA
1 stop7h 30mSouthwest
Deal found 12/24$569
This Delta deal was found by Cheapflights users on 12/26. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/275:25 amSEA - STL
1 stop5h 58mDelta
Thu 1/12:18 pmSTL - SEA
1 stop6h 13mDelta
Deal found 12/26$579
This Southwest deal was found by Cheapflights users on 12/25. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/297:00 amSEA - STL
2 stops9h 15mSouthwest
Wed 12/314:00 pmSTL - SEA
1 stop7h 50mSouthwest
Deal found 12/25$584
This Southwest deal was found by Cheapflights users on 12/24. 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.
Thu 12/259:35 amSEA - STL
1 stop6h 55mSouthwest
Wed 12/314:00 pmSTL - SEA
1 stop7h 50mSouthwest
Deal found 12/24$608
This Alaska Airlines deal was found by Cheapflights users on 12/25. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/275:56 pmSEA - STL
Nonstop3h 54mAlaska Airlines
Thu 1/17:00 amSTL - SEA
Nonstop4h 39mAlaska Airlines
Deal found 12/25$617
This American Airlines deal was found by Cheapflights users on 12/25. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/2511:34 pmSEA - STL
1 stop7h 22mAmerican Airlines
Wed 12/315:00 amSTL - SEA
1 stop9h 37mAmerican Airlines
Deal found 12/25$619
This American Airlines deal was found by Cheapflights users on 12/24. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/2511:49 amSEA - STL
1 stop9h 07mAmerican Airlines
Sat 1/35:00 amSTL - SEA
1 stop9h 37mAmerican Airlines
Deal found 12/24$653

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 December 27, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$217
(Kiwi.com)

One-way from

$68
(Kiwi.com)

Popular in

December

Cheapest in

January

Average price

$606

Good round-trip deal

$333 or less

Good one-way deal

$173 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
Highest demand for flights based on searches. 8% potential increase in price ($35 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 5% potential price decrease ($20 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in December 2025
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 December 27, 2025.
Use the filters below to find and compare flights from Seattle to St. Louis that are best for you.

Fly from

Seattle

Fly to

St. Louis

Route

Depart

Return

Price

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Thu 2/26

1:16 pm-1:09 pm

1 stop21h 53m

Lambert-St Louis

Sun 3/1

10:11 pm-7:59 pm

2 stops23h 48m

$232

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Thu 1/15

6:35 am-3:55 pm

1 stop7h 20m

Lambert-St Louis

Sun 1/18

6:05 am-1:15 pm

1 stop9h 10m

$233

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Fri 2/6

7:55 am-1:54 pm

Nonstop3h 59m

Lambert-St Louis

Mon 2/9

2:50 pm-5:25 pm

Nonstop4h 35m

$237

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Thu 2/19

6:07 pm-11:59 pm

Nonstop3h 52m

Lambert-St Louis

Mon 2/23

2:47 pm-5:26 pm

Nonstop4h 39m

$237

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Sun 3/1

6:07 pm-11:59 pm

Nonstop3h 52m

Lambert-St Louis

Fri 3/6

7:00 am-9:42 am

Nonstop4h 42m

$237

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Thu 3/26

9:26 am-3:20 pm

Nonstop3h 54m

Lambert-St Louis

Mon 3/30

4:20 pm-6:53 pm

Nonstop4h 33m

$237

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Mon 2/23

6:07 pm-11:59 pm

Nonstop3h 52m

Lambert-St Louis

Fri 2/27

2:47 pm-5:26 pm

Nonstop4h 39m

$237

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Thu 3/5

6:07 pm-11:59 pm

Nonstop3h 52m

Lambert-St Louis

Mon 3/9

2:47 pm-5:26 pm

Nonstop4h 39m

$237

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Fri 1/23

7:55 am-1:54 pm

Nonstop3h 59m

Lambert-St Louis

Sun 1/25

2:50 pm-5:25 pm

Nonstop4h 35m

$237

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Thu 1/22

5:00 am-4:03 pm

2 stops9h 03m

Lambert-St Louis

Sun 1/25

6:30 am-11:32 am

1 stop7h 02m

$244

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/25

Showing 1-10 of 19 results
1
2

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 December.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy2 starsTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*1 star
eDreamsPrice Accuracy3 starsTrust Score*3 stars
PricelinePrice Accuracy1 starTrust Score*3 stars
CheapfaremartPrice Accuracy-Trust Score*1 star
CheapTicketsDealPrice Accuracy3 starsTrust Score*3 stars
JustAirTicketPrice Accuracy-Trust Score*1 star

*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 eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on Seattle-St. Louis flight deals on Cheapflights vs. eDreams >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 eDreams the most. eDreams 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?

Use this chart to determine the optimal time to book a round-trip flight from Seattle to St. Louis. Price data was last updated on December 19, 2025.

The best time to book flights from Seattle to St. Louis is 67 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 $158). Flying from Seattle to St. Louis in December is currently the most expensive (average of $288). 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 December 27, 2025.

When flying from Seattle to St. Louis, the time of day you fly usually plays a role in the price. Save by searching for a flight in the evening, which can drop the price by up to 38% versus a flight in the morning.

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

Use this chart to determine the cheapest time to fly round-trip from Seattle to St. Louis. Price data was last updated on December 20, 2025.

Travelers seeking maximum savings on their Seattle to St. Louis flight should consider departing on Tuesday evenings when fares are most often at their lowest. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.

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
Airports
SEA

Plan to arrive at SEA two hours before your flight. Use SEA Spot Saver for security appointments to reduce wait times.

Read more about SEABy Brandon Schultz
STL

Use the MetroLink light rail from STL for a convenient and economical way to reach downtown St. Louis in about 40 minutes.

Read more about STLBy Taryn White
Our travel experts
Taryn White

Taryn White

Expert on STL

Taryn White

Taryn White

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

Brandon Schultz

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 December 27, 2025.
Peruse reviews from past customers who have flown with Alaska Airlines, Southwest, and Delta 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
8.0
Very good
11,542 reviews

Overall

8.0

Comfort

7.8

Boarding

8.1

Food

7.1

Crew

8.5

Entertainment

7.0

Reviews

1 / 20
8.0
Excellent

Anonymous,Sep 2025

SEA - MKE

The crew were excellent, flight good, but the actual space for a person to occupy for 4 hours seems to get smaller and smaller 🤣. I am not overweight, and average height….very uncomfortable,, especially when I couldn’t recliner the seat at all, and the pocket in front doesn’t accommodate a water bottle.
Alaska Airlines
8.0
Very good
11,542 reviews
Alaska Airlines
8.0
Very good
11,542 reviews

Overall

8.0

Comfort

7.8

Boarding

8.1

Food

7.1

Crew

8.5

Entertainment

7.0

Reviews

1 / 20
8.0
Excellent

Anonymous,Sep 2025

SEA - MKE

The crew were excellent, flight good, but the actual space for a person to occupy for 4 hours seems to get smaller and smaller 🤣. I am not overweight, and average height….very uncomfortable,, especially when I couldn’t recliner the seat at all, and the pocket in front doesn’t accommodate a water bottle.
Southwest
8.0
Very good
4,258 reviews
Alaska Airlines
8.0
Very good
11,542 reviews

Overall

8.0

Comfort

7.8

Boarding

8.1

Food

7.1

Crew

8.5

Entertainment

7.0

Reviews

1 / 20
8.0
Excellent

Anonymous,Sep 2025

SEA - MKE

The crew were excellent, flight good, but the actual space for a person to occupy for 4 hours seems to get smaller and smaller 🤣. I am not overweight, and average height….very uncomfortable,, especially when I couldn’t recliner the seat at all, and the pocket in front doesn’t accommodate a water bottle.
Delta
7.9
Good
8,017 reviews
Alaska Airlines
8.0
Very good
11,542 reviews

Overall

8.0

Comfort

7.8

Boarding

8.1

Food

7.1

Crew

8.5

Entertainment

7.0

Reviews

1 / 20
8.0
Excellent

Anonymous,Sep 2025

SEA - MKE

The crew were excellent, flight good, but the actual space for a person to occupy for 4 hours seems to get smaller and smaller 🤣. I am not overweight, and average height….very uncomfortable,, especially when I couldn’t recliner the seat at all, and the pocket in front doesn’t accommodate a water bottle.
Hawaiian Airlines
7.8
Good
2,820 reviews
Alaska Airlines
8.0
Very good
11,542 reviews

Overall

8.0

Comfort

7.8

Boarding

8.1

Food

7.1

Crew

8.5

Entertainment

7.0

Reviews

1 / 20
8.0
Excellent

Anonymous,Sep 2025

SEA - MKE

The crew were excellent, flight good, but the actual space for a person to occupy for 4 hours seems to get smaller and smaller 🤣. I am not overweight, and average height….very uncomfortable,, especially when I couldn’t recliner the seat at all, and the pocket in front doesn’t accommodate a water bottle.
American Airlines
7.2
Good
11,066 reviews
Alaska Airlines
8.0
Very good
11,542 reviews

Overall

8.0

Comfort

7.8

Boarding

8.1

Food

7.1

Crew

8.5

Entertainment

7.0

Reviews

1 / 20
8.0
Excellent

Anonymous,Sep 2025

SEA - MKE

The crew were excellent, flight good, but the actual space for a person to occupy for 4 hours seems to get smaller and smaller 🤣. I am not overweight, and average height….very uncomfortable,, especially when I couldn’t recliner the seat at all, and the pocket in front doesn’t accommodate a water bottle.

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 52m 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 4 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?

    Frontier, Southwest, and Alaska Airlines can get you from Seattle to St. Louis in just under 3h 59m. Your travel time can differ by up to 17h 54m. 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 $94. Other airlines that can offer you cheap pricing are Frontier, from $136, and United Airlines, from $157. These flights start at 75% 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 Frontier and American Airlines, with prices starting from $86 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 (83%), Air Tahiti Nui (83%), Qatar Airways (78%).

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

    The cheapest flight price from Seattle to St. Louis is $118. On average you can expect to pay $432. The most popular route, (Seattle/Tacoma Intl - Lambert-St Louis), can usually be booked for $177.

  • 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 $158). Flying from Seattle to St. Louis in December is currently the most expensive (average of $288). 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
Swansea
Fairview Heights
Maryland Heights
Collinsville
Eureka
Glencoe
Chesterfield
Alton
Farmington
Festus

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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 December 27, 2025.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$123Average$259FlexibilityNo cancel feeOn-timeN/A
FrontierCheapest$136Average$285FlexibilityNo cancel feeOn-time62%
SouthwestCheapest$182Average$341FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$188Average$488FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$216Average$368FlexibilityNo cancel feeOn-time69%
Hawaiian AirlinesCheapest$219Average$395FlexibilityNo cancel feeOn-time85%
Alaska AirlinesCheapest$245Average$421FlexibilityNo cancel feeOn-time75%

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