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Cheap flights from Seattle to St. Louis from $63

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Seattle to St. Louis departing on 1/9. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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0 bags

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Find the cheapest flights from Seattle to St. Louis

Cheap round-trip flights

Enter your travel dates to find the best prices.
Alaska Airlines Logo
6:05 pm - 11:59 pm
SEA
-
STL
3h 54mnonstop
Alaska Airlines Logo
5:26 pm - 7:59 pm
STL
-
SEA
4h 33mnonstop
$237Alaska Airlines
Thu, Jan 1 - Mon, Jan 5
United Airlines Logo
9:00 am - 8:58 pm
SEA
-
STL
9h 58m2 stops
United Airlines Logo
4:35 pm - 10:59 pm
STL
-
SEA
8h 24m1 stop
$242United Airlines
Fri, Jan 30 - Mon, Feb 2
Delta Logo
5:25 am - 1:23 pm
SEA
-
STL
5h 58m1 stop
Delta Logo
5:00 pm - 11:22 pm
STL
-
SEA
8h 22m1 stop
$243Delta
Fri, Dec 26 - Wed, Jan 7
Multiple Airlines Logo
9:23 pm - 12:12 pm
SEA
-
STL
12h 49m1 stop
Multiple Airlines Logo
2:47 pm - 5:26 pm
STL
-
SEA
4h 39mnonstop
$255Multiple Airlines
Sun, Jan 11 - Fri, Mar 6
United Airlines Logo
1:55 pm - 10:22 pm
SEA
-
STL
6h 27m1 stop
United Airlines Logo
8:45 am - 6:27 pm
STL
-
SEA
11h 42m2 stops
$258United Airlines
Mon, Jan 5 - Wed, Jan 7
Multiple Airlines Logo
7:55 am - 1:54 pm
SEA
-
STL
3h 59mnonstop
Multiple Airlines Logo
1:07 pm - 7:47 pm
STL
-
SEA
8h 40m1 stop
$262Multiple Airlines
Fri, Jan 9 - Mon, Jan 12
American Airlines Logo
12:14 am - 8:35 am
SEA
-
STL
6h 21m1 stop
American Airlines Logo
9:25 am - 3:34 pm
STL
-
SEA
8h 09m1 stop
$263American Airlines
Thu, Jan 1 - Tue, Jan 6
Southwest Logo
5:15 am - 5:10 pm
SEA
-
STL
9h 55m2 stops
Southwest Logo
3:50 pm - 11:05 pm
STL
-
SEA
9h 15m2 stops
$267Southwest
Tue, Jan 27 - Wed, Feb 4
Alaska Airlines Logo
6:00 pm - 11:55 pm
SEA
-
STL
3h 55mnonstop
Alaska Airlines Logo
2:55 pm - 5:22 pm
STL
-
SEA
4h 27mnonstop
$269Alaska Airlines
Thu, Mar 26 - Mon, Mar 30
Multiple Airlines Logo
7:23 pm - 9:21 pm
SEA
-
STL
23h 58m1 stop
Multiple Airlines Logo
2:50 pm - 5:25 pm
STL
-
SEA
4h 35mnonstop
$271Multiple Airlines
Thu, Jan 8 - Thu, Jan 15

Alaska Airlines flights from Seattle to St. Louis

Our best Alaska Airlines deals on Seattle to St. Louis flight tickets
Alaska Airlines
Jan 1
SEA6:05 pmSeattle/Tacoma Intl
3h 54m
STL11:59 pmLambert-St Louis
Jan 5
STL5:26 pmLambert-St Louis
4h 33m
SEA7:59 pmSeattle/Tacoma Intl
$237
Find similar
Alaska Airlines
Mar 26
SEA6:00 pmSeattle/Tacoma Intl
3h 55m
STL11:55 pmLambert-St Louis
Mar 30
STL2:55 pmLambert-St Louis
4h 27m
SEA5:22 pmSeattle/Tacoma Intl
$269
Find similar
Alaska Airlines
Jan 2
SEA6:05 pmSeattle/Tacoma Intl
3h 54m
STL11:59 pmLambert-St Louis
Jan 6
STL7:00 amLambert-St Louis
4h 39m
SEA9:39 amSeattle/Tacoma Intl
$283
Find similar

Delta flights from Seattle to St. Louis

Our best Delta deals on Seattle to St. Louis flight tickets
Delta
Dec 26
SEA5:25 amSeattle/Tacoma Intl
5h 58m
1 stop
STL1:23 pmLambert-St Louis
Jan 7
STL5:00 pmLambert-St Louis
8h 22m
1 stop
SEA11:22 pmSeattle/Tacoma Intl
$243
Find similar
Delta
Jan 1
SEA5:25 amSeattle/Tacoma Intl
5h 58m
1 stop
STL1:23 pmLambert-St Louis
Jan 6
STL7:00 amLambert-St Louis
15h 48m
2 stops
SEA8:48 pmSeattle/Tacoma Intl
$272
Find similar
Delta
Dec 31
SEA12:55 amSeattle/Tacoma Intl
8h 17m
1 stop
STL11:12 amLambert-St Louis
Jan 5
STL7:00 amLambert-St Louis
7h 33m
1 stop
SEA12:33 pmSeattle/Tacoma Intl
$277
Find similar

momondo 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, momondo users made 832,500 searches. Data last updated December 11, 2025.
Use the filters below to find and compare flights from Seattle to St. Louis that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Thu 1/1

6:05 pm-11:59 pm

Nonstop3h 54m

Lambert-St Louis

Mon 1/5

5:26 pm-7:59 pm

Nonstop4h 33m

$237

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Fri 1/30

9:00 am-8:58 pm

2 stops9h 58m

Lambert-St Louis

Mon 2/2

4:35 pm-10:59 pm

1 stop8h 24m

$242

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Fri 12/26

5:25 am-1:23 pm

1 stop5h 58m

Lambert-St Louis

Wed 1/7

5:00 pm-11:22 pm

1 stop8h 22m

$243

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Sun 1/11

9:23 pm-12:12 pm

1 stop12h 49m

Lambert-St Louis

Fri 3/6

2:47 pm-5:26 pm

Nonstop4h 39m

$255

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Mon 1/5

1:55 pm-10:22 pm

1 stop6h 27m

Lambert-St Louis

Wed 1/7

8:45 am-6:27 pm

2 stops11h 42m

$258

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Fri 1/9

7:55 am-1:54 pm

Nonstop3h 59m

Lambert-St Louis

Mon 1/12

1:07 pm-7:47 pm

1 stop8h 40m

$262

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Thu 1/1

12:14 am-8:35 am

1 stop6h 21m

Lambert-St Louis

Tue 1/6

9:25 am-3:34 pm

1 stop8h 09m

$263

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Tue 1/27

5:15 am-5:10 pm

2 stops9h 55m

Lambert-St Louis

Wed 2/4

3:50 pm-11:05 pm

2 stops9h 15m

$267

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Thu 3/26

6:00 pm-11:55 pm

Nonstop3h 55m

Lambert-St Louis

Mon 3/30

2:55 pm-5:22 pm

Nonstop4h 27m

$269

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Thu 1/8

7:23 pm-9:21 pm

1 stop23h 58m

Lambert-St Louis

Thu 1/15

2:50 pm-5:25 pm

Nonstop4h 35m

$271

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to St. Louis from

How to get the cheapest flight ticket from Seattle to St. Louis

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest month to fly to St. Louis?

In general, September is the cheapest month to fly from Seattle to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $328. The month of October is another great option to travel to St. Louis, with average flight prices from Seattle averaging around $330.

What is the cheapest day to depart on your flight to St. Louis?

The cheapest day to depart on your flight to St. Louis is on a Thursday when prices can be found for as low as $392. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Monday because tickets tend to average around $496. These prices are subject to change though, so be sure to set up a Price Alert for flights to St. Louis.

What is the cheapest time of day to depart on your flight to St. Louis?

Flying to St. Louis from Seattle in the evening is the least expensive time of day to depart. momondo users have found prices as low as $267 when looking at flights departing in the evening. In the morning is when there is more demand to fly to St. Louis, so prices are often more expensive at around $439 per ticket.

What is the cheapest Seattle/Tacoma Intl to Lambert-St Louis flight route?

Fly from Seattle/Tacoma Intl to Lambert-St Louis for the best Seattle/Tacoma Intl - Lambert-St Louis flight prices

How far in advance should I book a flight to St. Louis?

You are more likely to see cheaper flights to St. Louis from Seattle when booking weeks ahead of your departure date. In general, you can expect to find flights to St. Louis for around $393 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to St. Louis from Seattle for as low as $262 on momondo.

What cabin class options are available on Seattle/Tacoma Intl to Lambert-St Louis flights?

There are 4 cabin classes available to choose from on Seattle/Tacoma Intl to Lambert-St Louis flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Can stopping save me money on Seattle to St. Louis flights?

You could potentially save up to 39% on your flight if you consider stops on a Seattle to St. Louis flight.

How have Seattle to St. Louis flight prices changed over time?

As of December 2025, prices for Seattle to St. Louis flights are approximately 15% cheaper when compared to flights at the same time last year.

When to book flights from Seattle to St. Louis

Are you open to changing your travel dates? Check out the ideal times to fly from Seattle to St. Louis according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Seattle to St. Louis (SEA to STL) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Seattle to St. Louis

Best Price Found

$173

Fastest flight time

3h 52m

Direct flights

Every day

Airports in St. Louis

1 airport
The best one-way flight to St. Louis from Seattle in the past 72 hours is $173. The best round-trip flight deal from Seattle to St. Louis found on momondo in the last 72 hours is $409.
The fastest flight from Seattle to St. Louis takes 3h 52m
Direct flights go from Seattle to St. Louis every day.
There is 1 airport in St. Louis. From Seattle there are direct flights to Lambert-St Louis (STL).
Search flight deals

  • How far is Seattle/Tacoma Intl to Lambert-St Louis by plane?

    The distance between Seattle/Tacoma Intl and Lambert-St Louis is about 1719.6 mi. Typically, this will take 3h 52m by plane in normal conditions.

  • When did momondo last update prices for flights from Seattle/Tacoma Intl Airport to Lambert-St Louis Airport?

    Prices for flights from Seattle/Tacoma Intl Airport to Lambert-St Louis Airport are updated daily.

  • How many operators does momondo search for flights from Seattle/Tacoma Intl Airport to Lambert-St Louis Airport?

  • How old do you have to be to fly from Seattle/Tacoma Intl Airport to Lambert-St Louis Airport?

    The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Seattle/Tacoma Intl Airport to Lambert-St Louis Airport.

  • What documentation or ID do you need to fly to Lambert-St Louis Airport?

    The travel and health documents you'll need for your trip to Lambert-St Louis Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Lambert-St Louis Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

  • What is the most popular plane model from Seattle to St. Louis?

  • What is the most popular airline from Seattle to St. Louis?

Best airlines flying from Seattle to St. Louis

Compare and see reviews for airlines that fly from Seattle to St. Louis with momondo
Airline
Rating
Free Cancellation
Price
DeltaPriceFrom $123Free CancellationRating
7.9
8,007 reviews
Search Delta flights
FrontierPriceFrom $136Free CancellationRating
5.8
3,084 reviews
Search Frontier flights
SouthwestPriceFrom $182Free CancellationRating
7.9
4,253 reviews
Search Southwest flights
American AirlinesPriceFrom $186Free CancellationRating
7.2
11,050 reviews
Search American Airlines flights
United AirlinesPriceFrom $216Free CancellationRating
7.4
9,095 reviews
Search United Airlines flights
Hawaiian AirlinesPriceFrom $219Free CancellationRating
7.8
2,817 reviews
Search Hawaiian Airlines flights
Alaska AirlinesPriceFrom $245Free CancellationRating
8.0
11,432 reviews
Search Alaska Airlines flights

  • Alaska Airlines Flights From Seattle to St. Louis

    Alaska Airlines is one of the most popular airlines flying from Seattle to St. Louis, operating 5 flights/week on average for this route. A good Alaska Airlines flight deal for Seattle to St. Louis starts from $245 round-trip, up to an average price of $429. Our users have rated Alaska Airlines at 8.0/10.

  • Hawaiian Airlines Flights From Seattle to St. Louis

    $219 is the best Hawaiian Airlines flight deal from Seattle to St. Louis found on momondo over the last 72 hours. The average Hawaiian Airlines ticket price found was closer to $395, however, with flight time and availability significantly affecting the price. Hawaiian Airlines (7.8/10 from 2,817 user reviews) flies into St. Louis from Seattle 9 times in an average week so prices can vary.

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
St. Charles
Chesterfield
Hermann
Fairview Heights
Maryland Heights
O'Fallon
Florissant
Fenton
Wentzville
St. Peters
Collinsville
Alton
Farmington
Festus
Clayton
Glencoe
Edwardsville
Eureka
Litchfield
Shrewsbury

Why use momondo?

Why should I use momondo to find a flight deal from Seattle to St. Louis?

Finding the right flight to St. Louis from Seattle is quick and easy when you have a range of options in front of you, from reputable agents and recognisable airlines. Options that can then be filtered down to find the best fit. That is what momondo does. We make finding flights to St. Louis quick and easy, saving you time and money.

Can I find flights from Seattle to St. Louis with flexible booking policies on momondo?

Yes. All flights to St. Louis from Seattle on momondo can be compared and filtered by various policies on offer, including flexible booking.

How can momondo help me find flights from Seattle to St. Louis?

momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from Seattle to St. Louis.

I’m not ready to book a flight from Seattle to St. Louis right now. Can momondo alert me if prices change?

If you are simply researching potential flights to St. Louis, momondo offers a useful price alert feature which will track prices for flights to St. Louis from Seattle and alert you when they change.

An easier way to manage your St. Louis trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.
Start using Trips
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