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

Within the past month, 51 users have taken a look at flights from Lambert-St Louis to Seattle/Tacoma Intl.

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

Airlines like Alaska Airlines fly from St. Louis to Seattle in about 4h 35m. The time it takes to get you to your destination is usually consistent. There are 1704 mi between St. Louis and Seattle. Most flights are nonstop.

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

Currently priced at $94, Delta will fly you from St. Louis to Seattle and back. In addition to Delta, many other airlines offer competitively priced options for your trip. Search Cheapflights for deals from Frontier and Southwest - these airlines can fly you to your destination from $118 and $176, respectively. You may be able to fly from St. Louis to Seattle for 72% 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 ($78), Southwest ($88), and American Airlines ($94).

Weekly flight availability from St. Louis to Seattle

The most flights from STL to SEA are scheduled on a Tuesday (10 on average). You will have fewer flight options on Thursday, which is when the least amount of flights are scheduled (3 on average).

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.

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).

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 $1,223, our data indicates the cheapest price to be $118. The most popular route (Lambert-St Louis - Seattle/Tacoma Intl), is priced around $177.

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 (83%), Japan Airlines (83%) and American Airlines (75%).

What are the most popular airlines that fly from St. Louis to Seattle?

Consider Alaska Airlines, Hawaiian Airlines or Delta when booking your flight. These represent the most popular airlines when flying from St. Louis to Seattle.

Most accurate provider : When it comes to deals on St. Louis-Seattle flights, users find the pricing of CheapOair to be most consistent on Cheapflights vs. CheapOair Users can find the same prices on St. Louis-Seattle flight deals on Cheapflights vs. CheapOair >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 CheapOair the most. CheapOair 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.

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 8 flights from Lambert-St Louis to Seattle/Tacoma Intl, all of which are around 4h 15m 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.

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.

$59+ Flights from St. Louis to Seattle

Home Search by date Vacation packages Hotels Flight deals Car rental Travel tips & news

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”

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 Lambert-St Louis to Seattle/Tacoma Intl are usually found in October or November, booked 66 days in advance, depart on a Tuesday or Thursday and return on a Thursday

Cheap 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 December 28, 2025.

Wed 12/317:43 pmSTL - SEA

1 stop18h 47mFrontier

Tue 1/61:00 pmSEA - STL

1 stop19h 02mFrontier

Deal found 12/26

$438

Wed 12/312:18 pmSTL - SEA

1 stop6h 13mDelta

Sat 1/35:25 amSEA - STL

1 stop5h 58mDelta

Deal found 12/27

$528

Wed 12/314:00 pmSTL - SEA

1 stop7h 50mSouthwest

Tue 1/65:15 amSEA - STL

2 stops9h 55mSouthwest

Deal found 12/26

$533

Fri 12/2611:41 amSTL - SEA

1 stop9h 33mAmerican Airlines

Tue 12/306:00 amSEA - STL

1 stop9h 24mAmerican Airlines

Deal found 12/25

$579

Fri 12/263:45 pmSTL - SEA

2 stops10h 50mSouthwest

Tue 12/302:45 pmSEA - STL

1 stop6h 20mSouthwest

Deal found 12/25

$584

Sat 12/2710:45 pmSTL - SEA

2 stops14h 50mSouthwest

Wed 12/315:40 amSEA - STL

1 stop5h 40mSouthwest

Deal found 12/27

$590

Wed 12/315:26 pmSTL - SEA

Nonstop4h 33mAlaska Airlines

Sat 1/310:28 amSEA - STL

Nonstop3h 58mAlaska Airlines

Deal found 12/27

$617

Tue 12/305:15 pmSTL - SEA

2 stops9h 40mSouthwest

Thu 1/11:10 pmSEA - STL

1 stop7h 10mSouthwest

Deal found 12/26

$624

Best flights from St. Louis to Seattle
Discover carefully curated flight deals from St. Louis to Seattle that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated December 28, 2025.

Sat 1/316:19 pmSTL - SEA

Nonstop4h 35mAlaska Airlines

Tue 2/37:55 amSEA - STL

Nonstop3h 59mAlaska Airlines

Deal found 12/25

$217

Fri 5/16:45 pmSTL - SEA

1 stop7h 14mDelta

Mon 5/1111:59 pmSEA - STL

1 stop6h 41mDelta

Deal found 12/27

$298

Thu 1/812:44 pmSTL - SEA

2 stops11h 59mUnited Airlines

Mon 1/125:00 amSEA - STL

1 stop6h 16mUnited Airlines

Deal found 12/25

$314

Sun 2/12:50 pmSTL - SEA

Nonstop4h 35mAlaska Airlines

Fri 2/67:55 amSEA - STL

Nonstop3h 59mAlaska Airlines

Deal found 12/26

$237

Sun 2/12:50 pmSTL - SEA

Nonstop4h 35mAlaska Airlines

Sun 2/87:55 amSEA - STL

Nonstop3h 59mAlaska Airlines

Deal found 12/27

$237

Thu 2/267:00 amSTL - SEA

Nonstop4h 42mAlaska Airlines

Mon 3/26:07 pmSEA - STL

Nonstop3h 52mAlaska Airlines

Deal found 12/27

$237

Fri 3/204:20 pmSTL - SEA

Nonstop4h 33mAlaska Airlines

Mon 3/239:26 amSEA - STL

Nonstop3h 54mAlaska Airlines

Deal found 12/26

$237

Thu 5/287:56 pmSTL - SEA

Nonstop4h 31mAlaska Airlines

Mon 6/15:55 pmSEA - STL

Nonstop4h 02mAlaska Airlines

Deal found 12/26

$269

Mon 6/16:20 pmSTL - SEA

1 stop6h 09mAlaska Airlines

Mon 6/85:55 pmSEA - STL

Nonstop4h 02mAlaska Airlines

Deal found 12/27

$287

Wed 6/102:58 pmSTL - SEA

Nonstop4h 29mAlaska Airlines

Tue 6/1612:37 pmSEA - STL

Nonstop3h 57mAlaska Airlines

Deal found 12/26

$289

Sat 6/137:30 pmSTL - SEA

Nonstop4h 30mAlaska Airlines

Tue 6/1612:37 pmSEA - STL

Nonstop3h 57mAlaska Airlines

Deal found 12/25

$289

Last-minute flights from St. Louis to Seattle
Discover last-minute flight deals from St. Louis to Seattle. Data last updated December 28, 2025 and is based on user searches.

Mon 1/510:10 pmSTL - SEA

1 stop21h 41mFrontier

Thu 1/87:23 pmSEA - STL

1 stop14h 49mFrontier

Deal found 12/25

$204

Sat 1/1011:55 amSTL - SEA

1 stop9h 23mAmerican Airlines

Tue 1/2012:45 pmSEA - STL

1 stop8h 27mAmerican Airlines

Deal found 12/26

$223

Wed 1/143:43 pmSTL - SEA

1 stop21h 26mFrontier

Mon 1/199:10 pmSEA - STL

2 stops39h 36mFrontier

Deal found 12/26

$205

Wed 1/143:43 pmSTL - SEA

1 stop21h 26mFrontier

Sun 1/1810:05 pmSEA - STL

2 stops20h 03mFrontier

Deal found 12/26

$218

Tue 1/202:50 pmSTL - SEA

Nonstop4h 35mAlaska Airlines

Wed 1/217:55 amSEA - STL

Nonstop3h 59mAlaska Airlines

Deal found 12/26

$217

Tue 1/202:50 pmSTL - SEA

Nonstop4h 35mAlaska Airlines

Fri 1/237:55 amSEA - STL

Nonstop3h 59mAlaska Airlines

Deal found 12/26

$227

Thu 1/229:57 amSTL - SEA

2 stops10h 29mUnited Airlines

Tue 1/2712:25 pmSEA - STL

1 stop6h 33mUnited Airlines

Deal found 12/26

$224

Fri 1/232:50 pmSTL - SEA

Nonstop4h 35mMultiple Airlines

Fri 1/3010:51 amSEA - STL

1 stop7h 57mMultiple Airlines

Deal found 12/26

$213

Fri 1/239:43 pmSTL - SEA

1 stop15h 56mFrontier

Fri 1/3012:34 pmSEA - STL

2 stops32h 59mFrontier

Deal found 12/26

$216

Sun 1/259:27 pmSTL - SEA

1 stop16h 29mFrontier

Sun 2/112:34 pmSEA - STL

1 stop22h 16mFrontier

Deal found 12/25

$191

Thu 1/2910:01 pmSTL - SEA

1 stop13h 35mMultiple Airlines

Sun 2/17:55 amSEA - STL

Nonstop3h 59mMultiple Airlines

Deal found 12/26

$215

Fri 1/303:37 pmSTL - SEA

1 stop10h 14mAmerican Airlines

Mon 2/212:45 pmSEA - STL

1 stop8h 27mAmerican Airlines

Deal found 12/26

$176

One-way flights from St. Louis to Seattle
Search for one-way flight options from St. Louis to Seattle. Find affordable one-way fares based on user searches. Data last updated December 28, 2025.

Sun 1/259:27 pmSTL - SEA

1 stop16h 29mFrontier

Deal found 12/26

$59

Sat 1/243:46 pmSTL - SEA

1 stop21h 33mFrontier

Deal found 12/27

$68

Tue 1/2011:55 amSTL - SEA

1 stop7h 50mAmerican Airlines

Deal found 12/26

$79

Fri 2/271:59 pmSTL - SEA

1 stop24h 02mFrontier

Deal found 12/27

$85

Mon 1/265:04 pmSTL - SEA

1 stop8h 47mAmerican Airlines

Deal found 12/26

$88

Mon 1/263:31 pmSTL - SEA

1 stop7h 15mDelta

Deal found 12/26

$89

Fri 1/167:27 pmSTL - SEA

1 stop21h 16mFrontier

Deal found 12/26

$96

Wed 1/283:46 pmSTL - SEA

2 stops19h 50mFrontier

Deal found 12/27

$99

Sat 2/282:51 pmSTL - SEA

2 stops20h 07mFrontier

Deal found 12/27

$100

Mon 6/226:59 pmSTL - SEA

1 stop7h 02mDelta

Deal found 12/25

$105

Fri 1/239:43 pmSTL - SEA

1 stop15h 56mFrontier

Deal found 12/27

$106

Find flight deals from St. Louis to Seattle

Most accurate provider	CheapOair 3 stars
Most trusted provider	CheapOair 3 stars
Round-trip from	$176 (American Airlines)
One-way from	$59 (Trip.com)
Popular in	July
Cheapest in	October
Average price	$363
Good round-trip deal	$304 or less
Good one-way deal	$163 or less

Provider with most accurate pricing for Lambert-St Louis-Seattle/Tacoma Intl flight deals.

Search Deals

Provider most trusted by Cheapflights users for Lambert-St Louis-Seattle/Tacoma Intl flights.

Search Deals

From Lambert-St Louis to Seattle/Tacoma Intl

Search Deals

One-way flight from Lambert-St Louis to Seattle/Tacoma Intl

Search Deals

Highest demand for flights based on searches. 15% potential increase in price ($61 potential increase over avg. RT price).

Search Deals

Cheapest flight prices on average. 2% potential price decrease ($9 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 Lambert-St Louis to Seattle/Tacoma Intl.

Search Deals

Price to beat on a one-way flight from Lambert-St Louis to Seattle/Tacoma Intl.

Search Deals

Fly from

Fly to

Route

Depart

Return

Price

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Sat 1/31

6:19 pm-8:54 pm

Nonstop4h 35m

Seattle/Tacoma Intl

Tue 2/3

7:55 am-1:54 pm

Nonstop3h 59m

$217

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Sun 2/1

2:50 pm-5:25 pm

Nonstop4h 35m

Seattle/Tacoma Intl

Fri 2/6

7:55 am-1:54 pm

Nonstop3h 59m

$237

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Sun 2/1

2:50 pm-5:25 pm

Nonstop4h 35m

Seattle/Tacoma Intl

Sun 2/8

7:55 am-1:54 pm

Nonstop3h 59m

$237

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Thu 2/26

7:00 am-9:42 am

Nonstop4h 42m

Seattle/Tacoma Intl

Mon 3/2

6:07 pm-11:59 pm

Nonstop3h 52m

$237

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Fri 3/20

4:20 pm-6:53 pm

Nonstop4h 33m

Seattle/Tacoma Intl

Mon 3/23

9:26 am-3:20 pm

Nonstop3h 54m

$237

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Thu 5/28

7:56 pm-10:27 pm

Nonstop4h 31m

Seattle/Tacoma Intl

Mon 6/1

5:55 pm-11:57 pm

Nonstop4h 02m

$269

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Mon 6/1

6:20 pm-10:29 pm

1 stop6h 09m

Seattle/Tacoma Intl

Mon 6/8

5:55 pm-11:57 pm

Nonstop4h 02m

$287

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Wed 6/10

2:58 pm-5:27 pm

Nonstop4h 29m

Seattle/Tacoma Intl

Tue 6/16

12:37 pm-6:34 pm

Nonstop3h 57m

$289

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Sat 6/13

7:30 pm-10:00 pm

Nonstop4h 30m

Seattle/Tacoma Intl

Tue 6/16

12:37 pm-6:34 pm

Nonstop3h 57m

$289

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Fri 5/1

6:45 pm-11:59 pm

1 stop7h 14m

Seattle/Tacoma Intl

Mon 5/11

11:59 pm-8:40 am

1 stop6h 41m

$298

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/26

Showing 1-10 of 22 results

Compare providers for flights from St. Louis to Seattle

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 December.

Provider	Price Accuracy	Trust Score*
Expedia	Price Accuracy2 stars	Trust Score*3 stars
FlightHub	Price Accuracy3 stars	Trust Score*1 star
eDreams	Price Accuracy3 stars	Trust Score*3 stars
Cheapflightsfares	Price Accuracy3 stars	Trust Score*2 stars
CheapOair	Price Accuracy3 stars	Trust Score*3 stars
Cheapfaremart	Price Accuracy-	Trust Score*1 star
JustAirTicket	Price 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 St. Louis-Seattle flights, users find the pricing of CheapOair to be most consistent on Cheapflights vs. CheapOair Users can find the same prices on St. Louis-Seattle flight deals on Cheapflights vs. CheapOair >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 CheapOair the most. CheapOair 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.

Cheapflights Insights

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

Prices

Airlines

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

The best time to book flights from St. Louis to Seattle is 66 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, April is the cheapest month in which you can book a flight from St. Louis to Seattle (average of $136). Flying from St. Louis to Seattle in August is currently the most expensive (average of $222). 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?

Unlike in the morning, when flights are generally more expensive, you can save up to 11% 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?

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

The best insider tips for St. Louis to Seattle flights

Cheapflights partnered with top experts to bring you the best recommendations for your St. Louis to Seattle trip

Airports

STL

Security lines at STL are usually quick, averaging 5 to 10 minutes during off-peak times. Check real-time wait times online before heading to the airport.

SEA

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

Our travel experts

Taryn White

Expert on STL

Brandon Schultz

Expert on SEA

Reviews of airlines servicing Seattle

Read through reviews of airlines operating flights from St. Louis to Seattle, such as Alaska Airlines, Southwest, and Delta. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.

Alaska Airlines

8.0

Very good

11,548 reviews

Reviews

1 / 20

10.0

Excellent

Anonymous,Dec 2025

SJC - SEA

The flight was great. Don’t have to make it better. Everything was OK.

Alaska Airlines

8.0

Very good

11,548 reviews

Alaska Airlines

8.0

Very good

11,548 reviews

Reviews

1 / 20

10.0

Excellent

Anonymous,Dec 2025

SJC - SEA

The flight was great. Don’t have to make it better. Everything was OK.

Southwest

8.0

Very good

4,256 reviews

Alaska Airlines

8.0

Very good

11,548 reviews

Reviews

1 / 20

10.0

Excellent

Anonymous,Dec 2025

SJC - SEA

The flight was great. Don’t have to make it better. Everything was OK.

Delta

7.9

Good

8,021 reviews

Alaska Airlines

8.0

Very good

11,548 reviews

Reviews

1 / 20

10.0

Excellent

Anonymous,Dec 2025

SJC - SEA

The flight was great. Don’t have to make it better. Everything was OK.

Hawaiian Airlines

7.8

Good

2,819 reviews

Alaska Airlines

8.0

Very good

11,548 reviews

Reviews

1 / 20

10.0

Excellent

Anonymous,Dec 2025

SJC - SEA

The flight was great. Don’t have to make it better. Everything was OK.

American Airlines

7.2

Good

11,069 reviews

Alaska Airlines

8.0

Very good

11,548 reviews

Reviews

1 / 20

10.0

Excellent

Anonymous,Dec 2025

SJC - SEA

The flight was great. Don’t have to make it better. Everything was OK.

Related info for your journey

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 8 flights from Lambert-St Louis to Seattle/Tacoma Intl, all of which are around 4h 15m 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, 51 users have taken a look at flights from Lambert-St Louis to Seattle/Tacoma Intl.
How long is the flight from St. Louis to Seattle?
Airlines like Alaska Airlines fly from St. Louis to Seattle in about 4h 35m. The time it takes to get you to your destination is usually consistent. There are 1704 mi between St. Louis and Seattle. Most flights are nonstop.
What are the cheapest airlines flying from St. Louis to Seattle round-trip?
Currently priced at $94, Delta will fly you from St. Louis to Seattle and back. In addition to Delta, many other airlines offer competitively priced options for your trip. Search Cheapflights for deals from Frontier and Southwest - these airlines can fly you to your destination from $118 and $176, respectively. You may be able to fly from St. Louis to Seattle for 72% 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 ($78), Southwest ($88), and American Airlines ($94).
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 (83%), Japan Airlines (83%) and American Airlines (75%).
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 $1,223, our data indicates the cheapest price to be $118. The most popular route (Lambert-St Louis - Seattle/Tacoma Intl), is priced around $177.
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, April is the cheapest month in which you can book a flight from St. Louis to Seattle (average of $136). Flying from St. Louis to Seattle in August is currently the most expensive (average of $222). 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

Tacoma

SeaTac

Lakewood

Ocean Shores

Olympia

Edmonds

Lynnwood

Renton

Puyallup

Kirkland

Kent

Tukwila

Cle Elum

Marysville

Fife

Aberdeen

Shoreline

Centralia

Federal Way

Chehalis

Browse thousands of different options on Cheapflights for your next trip

Alternative routes for St. Louis to Seattle

Complete your trip

Seattle car rentals

Seattle/Tacoma Intl Airport car rentals

Kenmore Air Harbor Airport car rentals

Spokane car rentals

Pasco car rentals

Bellingham car rentals

Walla Walla car rentals

Yakima car rentals

Downtown car rentals

Capitol Hill car rentals

West Seattle car rentals

Queen Anne car rentals

Other flights to Seattle

Top 7 airlines flying from St. Louis to Seattle

Airline	Cheapest	Average	Flexibility	On-time
Delta	Cheapest$94	Average$234	FlexibilityNo cancel fee	On-timeN/A
Frontier	Cheapest$120	Average$228	FlexibilityNo cancel fee	On-time62%
Southwest	Cheapest$176	Average$378	FlexibilityNo cancel fee	On-time63%
American Airlines	Cheapest$188	Average$400	FlexibilityNo cancel fee	On-time71%
United Airlines	Cheapest$193	Average$360	FlexibilityNo cancel fee	On-time69%
Alaska Airlines	Cheapest$237	Average$380	FlexibilityNo cancel fee	On-time75%
Hawaiian Airlines	Cheapest$237	Average$380	FlexibilityNo cancel fee	On-time85%

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.

$59+ 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 1/25. Fares are subject to change and may not be available on all flights or dates of travel.

Find cheap flights from St. Louis to Seattle with Cheapflights

1. Tell us where you want to go

2. Select your favorite providers

3. Compare prices and book

Cheapflights Tip: The best prices from Lambert-St Louis to Seattle/Tacoma Intl are usually found in October or November, booked 66 days in advance, depart on a Tuesday or Thursday and return on a Thursday

Cheap flight deals from St. Louis to Seattle

Cheapest flights from St. Louis to SeattleExplore 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 December 28, 2025.

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 December 28, 2025.

Find flight deals from St. Louis to Seattle

Most accurate provider

Most trusted provider

Round-trip from

One-way from

Popular in

Cheapest in

Average price

Good round-trip deal

Good one-way deal

Cheapflights Fare Finder

Use the filters below to find and compare flights from St. Louis to Seattle that are best for you.

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 December.

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.

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?

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

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

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

Weekly flight availability from St. Louis to Seattle

The best insider tips for St. Louis to Seattle 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 St. Louis to Seattle trip

Airports

STL

SEA

Our travel experts

Reviews of airlines servicing Seattle

Read through reviews of airlines operating flights from St. Louis to Seattle, such as Alaska Airlines, Southwest, and Delta. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.

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?

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

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

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

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

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

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

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

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

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

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

Traveling to a place near Seattle?

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for St. Louis to Seattle

See prices for flight routes from nearby airports that may be better suited for you.

Top 7 airlines flying from St. Louis to Seattle

100% Free

Book with Flexibility

Travel Smart

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 December 28, 2025.