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$55+ 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 4/30. Fares are subject to change and may not be available on all flights or dates of travel.
STL — SEA
Feb 8 — Feb 151
Sat 2/8
Sat 2/15
1 adult, Economy
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The best prices from Lambert-St Louis to Seattle/Tacoma Intl are usually found in February or October, booked 37 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 February 3, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$247
(Alaska Airlines)

One-way from

$55
(Frontier)

Popular in

July

Cheapest in

February

Average price

$276

Good round-trip deal

$379 or less

Good one-way deal

$260 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
Search Deals
Highest demand for flights based on searches. 19% potential increase in price ($87 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease ($12 potential savings vs. average RT price).
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Average for round-trip flights in February 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 February 3, 2025.

This Alaska Airlines deal was found by Cheapflights users on 2/2. 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.
Wed 3/57:00 amSTL - SEA
Nonstop4h 35mAlaska Airlines
Sun 3/96:11 pmSEA - STL
Nonstop3h 48mAlaska Airlines
Deal found 2/2$247
This Southwest deal was found by Cheapflights users on 2/2. 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.
Wed 3/56:30 amSTL - SEA
1 stop9h 20mSouthwest
Tue 3/116:40 amSEA - STL
2 stops9h 35mSouthwest
Deal found 2/2$252
This Delta deal was found by Cheapflights users on 2/1. 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.
Tue 2/185:00 pmSTL - SEA
1 stop9h 50mDelta
Fri 2/215:30 amSEA - STL
1 stop5h 48mDelta
Deal found 2/1$258
This Booking.com deal was found by Cheapflights users on 2/2. 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.
Thu 5/84:07 pmSTL - SEA
1 stop10h 37mFrontier
Sun 5/186:00 amSEA - STL
1 stop25h 09mFrontier
Deal found 2/2$260
This American Airlines deal was found by Cheapflights users on 2/3. 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 2/205:10 amSTL - SEA
1 stop7h 54mAmerican Airlines
Sun 2/2311:59 pmSEA - STL
1 stop9h 26mAmerican Airlines
Deal found 2/3$269
This Expedia deal was found by Cheapflights users on 2/2. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 3/211:08 pmSTL - SEA
1 stop13h 15mMultiple Airlines
Tue 3/118:26 amSEA - STL
Nonstop3h 59mMultiple Airlines
Deal found 2/2$274
This United Airlines deal was found by Cheapflights users on 2/2. 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.
Wed 2/269:00 amSTL - SEA
1 stop8h 52mUnited Airlines
Fri 2/287:13 pmSEA - STL
2 stops12h 52mUnited Airlines
Deal found 2/2$312

Find flights from St. Louis to Seattle within your budget

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 February 3, 2025.

Fly from

Any airport

Fly to

Any airport

Route

Depart

Return

Price

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Wed 3/5

7:00 am-9:35 am

Nonstop4h 35m

Seattle/Tacoma Intl

Sun 3/9

6:11 pm-11:59 pm

Nonstop3h 48m

$247

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Wed 3/5

6:30 am-1:50 pm

1 stop9h 20m

Seattle/Tacoma Intl

Tue 3/11

6:40 am-6:15 pm

2 stops9h 35m

$252

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Tue 2/18

5:00 pm-12:50 am

1 stop9h 50m

Seattle/Tacoma Intl

Fri 2/21

5:30 am-1:18 pm

1 stop5h 48m

$258

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Thu 5/8

4:07 pm-12:44 am

1 stop10h 37m

Seattle/Tacoma Intl

Sun 5/18

6:00 am-9:09 am

1 stop25h 09m

$260

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Thu 2/20

5:10 am-11:04 am

1 stop7h 54m

Seattle/Tacoma Intl

Sun 2/23

11:59 pm-11:25 am

1 stop9h 26m

$269

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Sun 3/2

11:08 pm-10:23 am

1 stop13h 15m

Seattle/Tacoma Intl

Tue 3/11

8:26 am-2:25 pm

Nonstop3h 59m

$274

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Wed 2/26

9:00 am-3:52 pm

1 stop8h 52m

Seattle/Tacoma Intl

Fri 2/28

7:13 pm-10:05 am

2 stops12h 52m

$312

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Wed 4/30

6:51 pm-12:44 am

1 stop7h 53m

$55

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Tue 3/4

5:00 pm-12:50 am

1 stop9h 50m

$109

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Tue 3/4

4:00 pm-7:02 pm

3 stops29h 02m

$112

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/3

Showing 1-10 of 15 results
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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 February.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars
CheapflightsfaresPrice Accuracy3 starsTrust Score*2 stars
AranGrantPrice Accuracy3 starsTrust Score*1 star
Kiwi.comPrice Accuracy3 starsTrust Score*2 stars
CheapfaremartPrice Accuracy-Trust Score*3 stars
CheapTicketsDealPrice Accuracy3 starsTrust 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 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 St. Louis-Seattle 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 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.

Travel insights for flights from St. Louis to Seattle

Get recent, data-driven insights about flights from St. Louis to Seattle including ideal travel times, pricing trends, and more.

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 January 31, 2025.

The best time to book flights from St. Louis to Seattle is 36 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 February 3, 2025.

Unlike in the morning, when flights are generally more expensive, you can save up to 16% on flights from St. Louis to Seattle by exploring options for tickets in the afternoon.

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 January 26, 2025.

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

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 February 3, 2025.
See what other customers who have flown with Southwest, Alaska Airlines 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.
Southwest
8.1
Very good
4,564 reviews

Entertainment

7.7

Overall

8.1

Comfort

8.1

Food

7.1

Boarding

8.2

Crew

8.7

Reviews

1 / 20

6.0
Good

Lauren,Dec 2024

MCI - DCA

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

Southwest
8.1
Very good
4,564 reviews
Southwest
8.1
Very good
4,564 reviews

Entertainment

7.7

Overall

8.1

Comfort

8.1

Food

7.1

Boarding

8.2

Crew

8.7

Reviews

1 / 20

6.0
Good

Lauren,Dec 2024

MCI - DCA

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

Alaska Airlines
8.0
Very good
9,681 reviews
Southwest
8.1
Very good
4,564 reviews

Entertainment

7.7

Overall

8.1

Comfort

8.1

Food

7.1

Boarding

8.2

Crew

8.7

Reviews

1 / 20

6.0
Good

Lauren,Dec 2024

MCI - DCA

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

Delta
8.0
Very good
8,427 reviews
Southwest
8.1
Very good
4,564 reviews

Entertainment

7.7

Overall

8.1

Comfort

8.1

Food

7.1

Boarding

8.2

Crew

8.7

Reviews

1 / 20

6.0
Good

Lauren,Dec 2024

MCI - DCA

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

United Airlines
7.4
Good
8,889 reviews
Southwest
8.1
Very good
4,564 reviews

Entertainment

7.7

Overall

8.1

Comfort

8.1

Food

7.1

Boarding

8.2

Crew

8.7

Reviews

1 / 20

6.0
Good

Lauren,Dec 2024

MCI - DCA

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

American Airlines
7.2
Good
10,000 reviews
Southwest
8.1
Very good
4,564 reviews

Entertainment

7.7

Overall

8.1

Comfort

8.1

Food

7.1

Boarding

8.2

Crew

8.7

Reviews

1 / 20

6.0
Good

Lauren,Dec 2024

MCI - DCA

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

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 3 flights from Lambert-St Louis to Seattle/Tacoma Intl, all of which are around 4h 24m for a nonstop flight. You can also purchase a plane ticket from 8 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, 45 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 $247, Alaska Airlines will fly you from St. Louis to Seattle and back. In addition to Alaska Airlines, many other airlines offer competitively priced options for your trip. Search Cheapflights for deals from Southwest and Delta - these airlines can fly you to your destination from $252 and $258, respectively. You may be able to fly from St. Louis to Seattle for 31% 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 Frontier ($55), Delta ($109), and Alaska Airlines ($119).

  • 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 (90%), Alaska Airlines (88%) and Air Tahiti Nui (88%).

  • 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 $1,128, our data indicates the cheapest price to be $173. The most popular route (Lambert-St Louis - Seattle/Tacoma Intl), is priced around $189.

  • Where are the most common layover locations when flying from St. Louis to Seattle?

    St. Louis to Seattle flights have a layover in Salt Lake City most of the time.

  • What are some popular things to do or see while on a layover in Salt Lake City?

    Most Salt Lake City visitors opt to spend their time experiencing Temple Square, Abravanel Hall, and Salt Lake Temple. Temple Square, Abravanel Hall, and Salt Lake Temple can be accessed by traveling approximately 4.7 mi, 4.7 mi, and 4.8 mi, respectively from Salt Lake City. Travelers in need of a car in Salt Lake City can rent one for about $55 per day.

  • Where are the least popular layover locations for St. Louis to Seattle flights?

    The least popular layover on flights from St. Louis to Seattle is Denver.

  • 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
Renton
Tacoma
Lacey
Federal Way
Ocean Shores
Leavenworth
Olympia
Marysville
Centralia
Cle Elum
Mukilteo
Aberdeen
Lakewood
Issaquah
Shoreline
Lynnwood
Shelton
Silverdale

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 February 3, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$118Average$196FlexibilityNo cancel feeOn-time62%
Spirit AirlinesCheapest$125Average$171FlexibilityNo cancel feeOn-time65%
DeltaCheapest$187Average$267FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$215Average$458FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$216Average$346FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$236Average$418FlexibilityNo cancel feeOn-time75%
SouthwestCheapest$266Average$464FlexibilityNo cancel feeOn-time63%
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