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$95+ Cheap flights from St. Louis to Seattle (STL - SEA)

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 5/28. Fares are subject to change and may not be available on all flights or dates of travel.
STL — SEA
Apr 30 — May 71
Wed 4/30
Wed 5/7
1 adult, Economy
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Find cheap flights from St. Louis to Seattle 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”

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Cheapflights Tip: The best prices from Lambert-St Louis to Seattle/Tacoma Intl are usually found in September or October, booked 55 days in advance, depart on a Wednesday or Thursday and return on a Thursday

Cheap flight deals from St. Louis to Seattle

Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Seattle (SEA). 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 April 25, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$181
(CheapOair)

One-way from

$95
(Delta)

Popular in

July

Cheapest in

September

Average price

$326

Good round-trip deal

$396 or less

Good one-way deal

$197 or less
Provider with most accurate pricing for Lambert-St Louis-Seattle/Tacoma Intl flight deals.
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Provider most trusted by Cheapflights users for Lambert-St Louis-Seattle/Tacoma Intl flights.
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From Lambert-St Louis to Seattle/Tacoma Intl
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One-way flight from Lambert-St Louis to Seattle/Tacoma Intl
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Highest demand for flights based on searches. 17% potential increase in price ($78 potential increase over avg. RT price).
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Cheapest flight prices on average. 3% potential price decrease ($11 potential savings vs. average RT price).
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Average for round-trip flights in April 2025
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Price to beat on a round-trip flight from Lambert-St Louis to Seattle/Tacoma Intl.
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Price to beat on a one-way flight from Lambert-St Louis to Seattle/Tacoma Intl.
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Find flight deals from St. Louis to Seattle

Cheapest flights from St. Louis to Seattle
Explore the most affordable flight options available from St. Louis to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 25, 2025.

This CheapOair deal was found by Cheapflights users on 4/24. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/306:58 pmSTL - SEA
1 stop7h 46mFrontier
Tue 5/66:00 amSEA - STL
1 stop25h 59mFrontier
Deal found 4/24$181
This Delta deal was found by Cheapflights users on 4/25. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 5/297:19 pmSTL - SEA
1 stop6h 40mDelta
Tue 6/311:50 pmSEA - STL
1 stop8h 57mDelta
Deal found 4/25$189
This American Airlines deal was found by Cheapflights users on 4/25. 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 5/295:00 amSTL - SEA
1 stop7h 15mAmerican Airlines
Fri 5/301:10 amSEA - STL
1 stop6h 44mAmerican Airlines
Deal found 4/25$213
This Southwest deal was found by Cheapflights users on 4/23. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/1011:40 amSTL - SEA
Nonstop4h 20mSouthwest
Tue 6/1710:40 pmSEA - STL
1 stop8h 20mSouthwest
Deal found 4/23$223
This Alaska Airlines deal was found by Cheapflights users on 4/24. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/97:36 pmSTL - SEA
Nonstop4h 24mAlaska Airlines
Sat 9/138:11 amSEA - STL
Nonstop4h 06mAlaska Airlines
Deal found 4/24$249
This Travelocity deal was found by Cheapflights users on 4/25. 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 Travelocity is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/166:53 pmSTL - SEA
1 stop7h 51mMultiple Airlines
Wed 5/216:04 pmSEA - STL
Nonstop4h 00mMultiple Airlines
Deal found 4/25$253
This Hawaiian Airlines deal was found by Cheapflights users on 4/25. 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 Hawaiian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/187:32 pmSTL - SEA
Nonstop4h 28mHawaiian Airlines
Wed 8/2012:39 pmSEA - STL
Nonstop3h 59mHawaiian Airlines
Deal found 4/25$269
This United Airlines deal was found by Cheapflights users on 4/24. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 5/131:41 pmSTL - SEA
2 stops9h 50mUnited Airlines
Tue 5/205:15 amSEA - STL
1 stop5h 30mUnited Airlines
Deal found 4/24$297

Cheapflights Fare Finder

Customize your flight search to find flights from St. Louis to Seattle 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 April 25, 2025.
Use the filters below to find and compare flights from St. Louis to Seattle that are best for you.

Fly from

St. Louis

Fly to

Seattle

Route

Depart

Return

Price

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Thu 5/29

6:00 am-12:59 pm

1 stop8h 59m

Seattle/Tacoma Intl

Wed 6/4

6:00 am-5:00 pm

1 stop9h 00m

$189

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Sat 5/10

8:15 pm-12:44 am

1 stop6h 29m

Seattle/Tacoma Intl

Fri 5/30

7:10 pm-10:09 am

1 stop12h 59m

$191

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Thu 5/29

5:00 am-10:15 am

1 stop7h 15m

Seattle/Tacoma Intl

Fri 5/30

1:10 am-9:54 am

1 stop6h 44m

$213

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Tue 6/10

11:40 am-2:00 pm

Nonstop4h 20m

Seattle/Tacoma Intl

Tue 6/17

10:40 pm-9:00 am

1 stop8h 20m

$223

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Tue 9/9

7:36 pm-10:00 pm

Nonstop4h 24m

Seattle/Tacoma Intl

Sat 9/13

8:11 am-2:17 pm

Nonstop4h 06m

$249

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Fri 5/16

6:53 pm-12:44 am

1 stop7h 51m

Seattle/Tacoma Intl

Wed 5/21

6:04 pm-12:04 am

Nonstop4h 00m

$253

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Mon 8/18

7:32 pm-10:00 pm

Nonstop4h 28m

Seattle/Tacoma Intl

Thu 8/21

6:03 pm-11:59 pm

Nonstop3h 56m

$269

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Tue 5/13

1:41 pm-9:31 pm

2 stops9h 50m

Seattle/Tacoma Intl

Tue 5/20

5:15 am-12:45 pm

1 stop5h 30m

$297

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Wed 5/28

7:19 pm-11:59 pm

1 stop6h 40m

$95

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Wed 4/30

6:58 pm-12:44 am

1 stop7h 46m

$99

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/25

Showing 1-10 of 18 results
1
2

Compare providers for flights from St. Louis to Seattle

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 St. Louis to Seattle in April.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*2 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars
CheapflightsfaresPrice Accuracy3 starsTrust Score*2 stars
Kiwi.comPrice Accuracy3 starsTrust Score*3 stars
CheapTicketsDealPrice Accuracy3 starsTrust Score*3 stars
JustAirTicketPrice Accuracy-Trust 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 St. Louis-Seattle flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on St. Louis-Seattle flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from St. Louis-Seattle flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on St. Louis-Seattle 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 St. Louis-Seattle flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

The best insider tips for St. Louis to Seattle flights

Snippets provided in this section are AI-generated based on a summarization of Cheapflights-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.
Cheapflights partnered with top experts to bring you the best recommendations for your St. Louis to Seattle trip
Airports
STL

Expect security screening at STL to take 5-10 minutes during off-peak times. Check real-time wait times online before heading to the airport.

Read more about STLby Taryn White
SEA

Use the Link light rail from SEA to downtown Seattle. It's inexpensive, runs every 10 minutes, and takes less than 40 minutes.

Read more about SEAby Brandon Schultz
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

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

Have a flexible travel schedule? Discover the best time to fly to Seattle from St. Louis 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 St. Louis to Seattle

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

Use this chart to determine the optimal time to book a round-trip flight from St. Louis to Seattle. Price data was last updated on April 18, 2025.

The best time to book flights from St. Louis to Seattle is 55 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 St. Louis to Seattle?

Currently, January is the cheapest month in which you can book a flight from St. Louis to Seattle (average of $238). Flying from St. Louis to Seattle in July is currently the most expensive (average of $411). 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 STL to SEA?

Find hourly flight availability from St. Louis to Seattle. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated April 25, 2025.

Unlike in the morning, when flights are generally more expensive, you can save up to 3% on flights from St. Louis to Seattle by exploring options for tickets in the evening.

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

Use this chart to determine the cheapest time to fly round-trip from St. Louis to Seattle. Price data was last updated on March 30, 2025.

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

Weekly flight availability from St. Louis to Seattle

Explore weekly flight availability from St. Louis to Seattle. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated April 25, 2025.

The most flights from STL to SEA are scheduled on a Monday (10 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (9 on average).

Rainfall in Seattle by month

Plan your trip to Seattle by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Seattle ranges from 0.7 - 6.6 inches per month. November is typically the wettest month, when rainfall can reach 6.6 in. July is typically the driest time to visit Seattle when rainfall is around 0.7 in.

Temperature in Seattle by month

Plan your trip to Seattle by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Seattle, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 66.2 F. Travelers looking to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 41.0 F).

Reviews of airlines servicing Seattle

Get insights into the airlines that provide service to Seattle. 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 Seattle. Reviews last updated April 25, 2025.
See what other customers who have flown with Alaska Airlines, Southwest and Delta from St. Louis to Seattle have to say. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
9,928 reviews

Crew

8.5

Boarding

8.2

Overall

8.0

Food

7.1

Entertainment

7.1

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Cheri,Jan 2025

FAT - SEA

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them
Alaska Airlines
8.0
Very good
9,928 reviews
Alaska Airlines
8.0
Very good
9,928 reviews

Crew

8.5

Boarding

8.2

Overall

8.0

Food

7.1

Entertainment

7.1

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Cheri,Jan 2025

FAT - SEA

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them
Southwest
8.0
Very good
4,287 reviews
Alaska Airlines
8.0
Very good
9,928 reviews

Crew

8.5

Boarding

8.2

Overall

8.0

Food

7.1

Entertainment

7.1

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Cheri,Jan 2025

FAT - SEA

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them
Delta
8.0
Very good
7,920 reviews
Alaska Airlines
8.0
Very good
9,928 reviews

Crew

8.5

Boarding

8.2

Overall

8.0

Food

7.1

Entertainment

7.1

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Cheri,Jan 2025

FAT - SEA

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them
Hawaiian Airlines
7.9
Good
2,395 reviews
Alaska Airlines
8.0
Very good
9,928 reviews

Crew

8.5

Boarding

8.2

Overall

8.0

Food

7.1

Entertainment

7.1

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Cheri,Jan 2025

FAT - SEA

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them
United Airlines
7.4
Good
8,685 reviews
Alaska Airlines
8.0
Very good
9,928 reviews

Crew

8.5

Boarding

8.2

Overall

8.0

Food

7.1

Entertainment

7.1

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Cheri,Jan 2025

FAT - SEA

Very friendly. I really liked that they had water for us in cartons not plastic. Impressed with Alaska Airlines, First time I had flown them

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Seattle. 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 St. Louis to Seattle?

    Booking a flight from Lambert-St Louis (STL) to Seattle/Tacoma Intl (SEA) is your only option if you wish to fly from St. Louis to Seattle. On a typical day, there are 9 flights from Lambert-St Louis to Seattle/Tacoma Intl, all of which are around 4h 17m for a nonstop flight. You can also purchase a plane ticket from 7 airlines when you book a flight from Lambert-St Louis to Seattle.

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

    Within the past month, 41 users have taken a look at flights from Lambert-St Louis to Seattle/Tacoma Intl.

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

    Currently priced at $181, Frontier will fly you from St. Louis to Seattle and back. In addition to Frontier, many other airlines offer competitively priced options for your trip. Search Cheapflights for deals from Delta and American Airlines - these airlines can fly you to your destination from $189 and $213, respectively. You may be able to fly from St. Louis to Seattle for 50% less than the average price by searching for these airlines.

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

    The cheapest airlines for a one-way flight from St. Louis to Seattle are Delta ($95), Frontier ($99), and Southwest ($100).

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

    The top 3 most reliable airlines when flying from St. Louis to Seattle are Qatar Airways (87%), Japan Airlines (87%) and Alaska Airlines (86%).

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

    Looking for the cheapest flight from St. Louis to Seattle? While on average our users pay $1,010, our data indicates the cheapest price to be $138. The most popular route (Lambert-St Louis - Seattle/Tacoma Intl), is priced around $182.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from St. Louis to Seattle 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 St. Louis to Seattle?

    Currently, January is the cheapest month in which you can book a flight from St. Louis to Seattle (average of $238). Flying from St. Louis to Seattle in July is currently the most expensive (average of $411). 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
SeaTac
Tukwila
Tacoma
Renton
Lakewood
Ocean Shores
Lacey
Leavenworth
Federal Way
Olympia
Shoreline
Cle Elum
Centralia
Kent
Aberdeen
Lynnwood
Shelton
Silverdale
Redmond
Issaquah

Browse thousands of different options on Cheapflights for your next trip

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Top 7 airlines flying from St. Louis to Seattle

Discover the top 7 airlines that operate flights from St. Louis to Seattle. 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 April 25, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$111Average$188FlexibilityNo cancel feeOn-time62%
DeltaCheapest$166Average$264FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$188Average$400FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$199Average$431FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$216Average$362FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$236Average$408FlexibilityNo cancel feeOn-time75%
Hawaiian AirlinesCheapest$237Average$398FlexibilityNo cancel feeOn-time85%

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