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Cheap flights from Seattle to St. Louis from C$ 168

SEA — STL
9 Dec — 16 Dec1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from Seattle to St. Louis

Enter your travel dates to find the best prices.

Cheapest flights from Seattle to St. Louis

Wed 9/1211:30 a.m. -
1 stop7h 58m
Sat 12/127:08 a.m. -
1 stop7h 28m
Deal found 5/11C$ 349
Tue 29/126:00 a.m. -
1 stop8h 36m
Fri 8/110:29 a.m. -
1 stop8h 17m
Deal found 9/11C$ 363
Tue 15/125:05 a.m. -
1 stop5h 51m
Tue 15/125:40 p.m. -
1 stop7h 03m
Deal found 5/11C$ 369
Sun 13/122:05 p.m. -
1 stop6h 54m
Mon 14/128:17 a.m. -
1 stop8h 06m
Deal found 6/11C$ 370
Thu 31/1211:59 p.m. -
1 stop8h 36m
Mon 11/16:20 a.m. -
1 stop10h 20m
Deal found 6/11C$ 377
Wed 9/126:30 a.m. -
1 stop8h 40m
Mon 14/128:25 a.m. -
2 stops12h 40m
Deal found 7/11C$ 379
Thu 10/126:30 a.m. -
1 stop8h 40m
Mon 14/128:25 a.m. -
2 stops12h 40m
Deal found 8/11C$ 393
Mon 14/125:05 a.m. -
1 stop5h 48m
Tue 15/128:40 a.m. -
2 stops9h 42m
Deal found 6/11C$ 396
Fri 11/126:00 a.m. -
1 stop9h 20m
Sat 12/125:00 p.m. -
1 stop7h 47m
Deal found 5/11C$ 407
Sat 5/125:05 a.m. -
2 stops9h 15m
Sat 12/125:25 p.m. -
1 stop6h 25m
Deal found 5/11C$ 412
Fri 11/127:55 a.m. -
2 stops9h 15m
Tue 15/125:15 p.m. -
1 stop7h 35m
Deal found 8/11C$ 414

Find flight deals from Seattle to St. Louis

Round-trip from

C$ 335

One-way from

C$ 168

Popular in

December

Cheapest in

January

Average price

C$ 524
Delta
  • Delta
  • 6/1-12/1
  • 2 total stops
  • 12h 40m total
  • Seattle to St. Louis
Search Deals
Delta
  • Delta
  • 26/12-31/12
  • 1 total stop
  • 8h 36m total
  • Seattle to St. Louis
Search Deals
High demand for flights, 7% potential price rise
Search Deals
Cheapest flight prices on average. 3% potential price decrease (C$ 33 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in November 2026
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Cheapflights Fare Finder

 
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

Cheapest round-trip
Quickest round-trip

SeattleSt. Louis

SEA Seattle/Tacoma Intl - STL Lambert-St Louis

SEASTL

Seattle/Tacoma Intl

Wed 20/1

12:30 p.m.-8:38 p.m.

1 stop6h 08m

Lambert-St Louis

Wed 31/12

12:00 a.m.-10:00 p.m.

Nonstop0h 00m

C$ 175

SeattleSt. Louis

SEA Seattle/Tacoma Intl - STL Lambert-St Louis

SEASTL

Seattle/Tacoma Intl

Tue 29/12

11:44 p.m.-10:42 a.m.

1 stop8h 58m

Lambert-St Louis

Wed 31/12

12:00 a.m.-10:00 p.m.

Nonstop0h 00m

C$ 175

SeattleSt. Louis

SEA Seattle/Tacoma Intl - STL Lambert-St Louis

SEASTL

Seattle/Tacoma Intl

Mon 1/2

9:01 a.m.-6:17 p.m.

1 stop7h 16m

Lambert-St Louis

Wed 31/12

12:00 a.m.-10:00 p.m.

Nonstop0h 00m

C$ 182

SeattleSt. Louis

SEA Seattle/Tacoma Intl - STL Lambert-St Louis

SEASTL

Seattle/Tacoma Intl

Sat 23/1

5:00 a.m.-5:13 p.m.

2 stops10h 13m

Lambert-St Louis

Wed 31/12

12:00 a.m.-10:00 p.m.

Nonstop0h 00m

C$ 182

SeattleSt. Louis

SEA Seattle/Tacoma Intl - STL Lambert-St Louis

SEASTL

Seattle/Tacoma Intl

Sun 31/1

10:52 a.m.-7:28 p.m.

1 stop6h 36m

Lambert-St Louis

Wed 31/12

12:00 a.m.-10:00 p.m.

Nonstop0h 00m

C$ 182

SeattleSt. Louis

SEA Seattle/Tacoma Intl - STL Lambert-St Louis

SEASTL

Seattle/Tacoma Intl

Sun 27/12

11:59 p.m.-10:35 a.m.

1 stop8h 36m

Lambert-St Louis

Wed 31/12

12:00 a.m.-10:00 p.m.

Nonstop0h 00m

C$ 189

SeattleSt. Louis

SEA Seattle/Tacoma Intl - STL Lambert-St Louis

SEASTL

Seattle/Tacoma Intl

Mon 14/12

1:45 p.m.-11:26 p.m.

1 stop7h 41m

Lambert-St Louis

Wed 31/12

12:00 a.m.-10:00 p.m.

Nonstop0h 00m

C$ 189

SeattleSt. Louis

SEA Seattle/Tacoma Intl - STL Lambert-St Louis

SEASTL

Seattle/Tacoma Intl

Fri 25/12

9:30 a.m.-8:43 p.m.

1 stop9h 13m

Lambert-St Louis

Wed 31/12

12:00 a.m.-10:00 p.m.

Nonstop0h 00m

C$ 189

SeattleSt. Louis

SEA Seattle/Tacoma Intl - STL Lambert-St Louis

SEASTL

Seattle/Tacoma Intl

Thu 10/12

9:01 a.m.-6:11 p.m.

1 stop7h 10m

Lambert-St Louis

Wed 31/12

12:00 a.m.-10:00 p.m.

Nonstop0h 00m

C$ 189

SeattleSt. Louis

SEA Seattle/Tacoma Intl - STL Lambert-St Louis

SEASTL

Seattle/Tacoma Intl

Sat 9/1

8:10 a.m.-8:10 p.m.

2 stops10h 00m

Lambert-St Louis

Wed 31/12

12:00 a.m.-10:00 p.m.

Nonstop0h 00m

C$ 239

Flights are sorted by cheapest round-trip flights first.

Deals found on 8/11

Showing 1-10 of 20 resultsSorted by cheapest first
1
2

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

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?

The price you pay for your flight from Seattle to St. Louis may vary depending on when you book. For the best chance of a lower fare, look to book 76 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

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 C$ 335). Flying from Seattle to St. Louis in December is currently the most expensive (average of C$ 859). 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?

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Seattle to St. Louis as you normally would.

How much does it cost to fly round-trip from Seattle to St. Louis?

Airfare is typical for this route at the moment.

Seattle to St. Louis flights typically cost between C$ 319 and C$ 859 in January.
The cheapest round-trip price found within the last 5 days was C$ 335 on Delta (9 Jan-16 Jan).

Reviews of airlines servicing St. Louis

Get a feel of what it's like to fly with Alaska Airlines from Seattle to St. Louis by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
7.9
Good
13,159 reviews
Check prices

Food

7.0

Entertainment

7.0

Crew

8.5

Comfort

7.8

Boarding

8.1

Overall

7.9

Reviews

1 / 20
4.0
Okay

Anonymous,Jun 2026

SEA - RNO

There was a delay and my husband needs a wheelchair and we were moved from 1 gate to another.
Alaska Airlines
7.9
Good
13,159 reviews
Alaska Airlines
7.9
Good
13,159 reviews
Check prices

Food

7.0

Entertainment

7.0

Crew

8.5

Comfort

7.8

Boarding

8.1

Overall

7.9

Reviews

1 / 20
4.0
Okay

Anonymous,Jun 2026

SEA - RNO

There was a delay and my husband needs a wheelchair and we were moved from 1 gate to another.

Related info for your journey

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

    Flights from Seattle/Tacoma Intl to Lambert-St Louis have been viewed 2 times in the past calendar month.

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

    For as low as C$ 349, Delta can have you in St. Louis from Seattle in 6h 11m. Seattle and St. Louis are separated by a distance of 2742 km. When browsing for deals, the options you’ll see will be for both direct flights and flights with stops.

  • What is the cheapest airline to fly from Seattle to St. Louis round-trip?

    Flying on Alaska Airlines is currently your cheapest option to St. Louis, with prices starting at C$ 334. Alaska Airlines is 45% cheaper than the average price of flights available within the next 90 days to this destination.

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

    The top 3 most reliable airlines when flying from Seattle to St. Louis are Qatar Airways (98%), Japan Airlines (92%) and Alaska Airlines (90%).

  • 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 C$ 335). Flying from Seattle to St. Louis in December is currently the most expensive (average of C$ 859). 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

Travelling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
Chesterfield

Browse thousands of different options on Cheapflights for your next trip

Top airline flying from Seattle to St. Louis

AirlineCheapestAverageFlexibilityOn-time
Alaska AirlinesCheapestC$ 334AverageC$ 518FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines flights

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