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Cheap flights from Seattle to St. Louis from C$ 146

SEA — STL
22 Oct — 29 Oct1
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

Sat 24/108:25 a.m. -
1 stop6h 13m
Thu 29/102:38 p.m. -
1 stop9h 27m
Deal found 17/9C$ 311
Mon 2/1111:20 a.m. -
2 stops11h 30m
Sat 7/115:50 a.m. -
1 stop7h 00m
Deal found 17/9C$ 313
Sun 1/115:30 a.m. -
1 stop6h 02m
Thu 5/115:00 p.m. -
1 stop7h 05m
Deal found 17/9C$ 318
Tue 20/1012:10 a.m. -
1 stop7h 05m
Sat 24/108:25 a.m. -
2 stops13h 40m
Deal found 21/9C$ 320
Thu 5/1111:20 a.m. -
2 stops11h 35m
Sun 8/117:15 p.m. -
1 stop7h 30m
Deal found 22/9C$ 325
Tue 3/115:15 a.m. -
2 stops13h 50m
Tue 10/1111:20 a.m. -
2 stops9h 20m
Deal found 19/9C$ 327
Mon 26/108:40 p.m. -
1 stop13h 00m
Fri 30/105:50 p.m. -
2 stops8h 50m
Deal found 17/9C$ 334
Thu 22/105:30 a.m. -
1 stop6h 02m
Sat 31/1010:35 a.m. -
1 stop10h 00m
Deal found 19/9C$ 348
Thu 22/105:30 a.m. -
1 stop6h 02m
Mon 26/102:38 p.m. -
1 stop9h 27m
Deal found 19/9C$ 355
Wed 21/107:00 a.m. -
1 stop6h 43m
Sun 25/108:00 a.m. -
1 stop8h 39m
Deal found 17/9C$ 367
Fri 30/105:05 a.m. -
1 stop5h 33m
Tue 3/111:08 p.m. -
2 stops10h 11m
Deal found 21/9C$ 377

Find flight deals from Seattle to St. Louis

Round-trip from

C$ 311

One-way from

C$ 146

Popular in

December

Cheapest in

January

Average price

C$ 598
Delta
  • Delta
  • 24/10-29/10
  • 2 total stops
  • 15h 40m total
  • Seattle to St. Louis
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Southwest
  • Southwest
  • 7/11-31/12
  • 1 total stop
  • 6h 20m total
  • Seattle to St. Louis
Search Deals
High demand for flights, 7% potential price rise
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Cheapest flight prices on average. 2% potential price decrease (C$ 25 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in September 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

SeattleSt. Louis

SEA Seattle/Tacoma Intl - STL Lambert-St Louis

SEASTL

Seattle/Tacoma Intl

Wed 28/10

6:00 a.m.-6:05 p.m.

2 stops10h 05m

Lambert-St Louis

Wed 31/12

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

Nonstop0h 00m

C$ 167

SeattleSt. Louis

SEA Seattle/Tacoma Intl - STL Lambert-St Louis

SEASTL

Seattle/Tacoma Intl

Mon 2/11

11:20 a.m.-12:50 a.m.

2 stops11h 30m

Lambert-St Louis

Wed 31/12

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

Nonstop0h 00m

C$ 167

SeattleSt. Louis

SEA Seattle/Tacoma Intl - STL Lambert-St Louis

SEASTL

Seattle/Tacoma Intl

Tue 27/10

6:00 a.m.-6:05 p.m.

2 stops10h 05m

Lambert-St Louis

Wed 31/12

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

Nonstop0h 00m

C$ 167

SeattleSt. Louis

SEA Seattle/Tacoma Intl - STL Lambert-St Louis

SEASTL

Seattle/Tacoma Intl

Thu 17/12

5:35 p.m.-5:26 a.m.

1 stop9h 51m

Lambert-St Louis

Wed 31/12

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

Nonstop0h 00m

C$ 209

SeattleSt. Louis

SEA Seattle/Tacoma Intl - STL Lambert-St Louis

SEASTL

Seattle/Tacoma Intl

Mon 19/10

10:48 p.m.-3:43 p.m.

2 stops14h 55m

Lambert-St Louis

Wed 31/12

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

Nonstop0h 00m

C$ 251

SeattleSt. Louis

SEA Seattle/Tacoma Intl - STL Lambert-St Louis

SEASTL

Seattle/Tacoma Intl

Sat 24/10

6:03 p.m.-11:59 p.m.

Nonstop3h 56m

Lambert-St Louis

Wed 31/12

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

Nonstop0h 00m

C$ 265

SeattleSt. Louis

SEA Seattle/Tacoma Intl - STL Lambert-St Louis

SEASTL

Seattle/Tacoma Intl

Fri 25/12

9:41 a.m.-3:34 p.m.

Nonstop3h 53m

Lambert-St Louis

Wed 31/12

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

Nonstop0h 00m

C$ 314

SeattleSt. Louis

SEA Seattle/Tacoma Intl - STL Lambert-St Louis

SEASTL

Seattle/Tacoma Intl

Mon 19/10

6:03 p.m.-11:59 p.m.

Nonstop3h 56m

Lambert-St Louis

Wed 31/12

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

Nonstop0h 00m

C$ 314

SeattleSt. Louis

SEA Seattle/Tacoma Intl - STL Lambert-St Louis

SEASTL

Seattle/Tacoma Intl

Tue 16/3

8:32 a.m.-2:26 p.m.

Nonstop3h 54m

Lambert-St Louis

Wed 31/12

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

Nonstop0h 00m

C$ 314

SeattleSt. Louis

SEA Seattle/Tacoma Intl - STL Lambert-St Louis

SEASTL

Seattle/Tacoma Intl

Thu 19/11

8:22 a.m.-2:25 p.m.

Nonstop4h 03m

Lambert-St Louis

Wed 31/12

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

Nonstop0h 00m

C$ 314

Flights are sorted by cheapest round-trip flights first.

Deals found on 18/9

Showing 1-10 of 24 resultsSorted by cheapest first
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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$ 332). Flying from Seattle to St. Louis in December is currently the most expensive (average of C$ 785). 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 below average for this route at the moment.

Seattle to St. Louis flights typically cost between C$ 411 and C$ 847 in October.
The cheapest round-trip price found within the last 5 days was C$ 311 on Delta (24 Oct-29 Oct).

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
12,953 reviews
Check prices

Entertainment

7.0

Boarding

8.1

Overall

7.9

Crew

8.5

Food

7.0

Comfort

7.8

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
12,953 reviews
Alaska Airlines
7.9
Good
12,953 reviews
Check prices

Entertainment

7.0

Boarding

8.1

Overall

7.9

Crew

8.5

Food

7.0

Comfort

7.8

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$ 367, Delta can have you in St. Louis from Seattle in 6h 43m. 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$ 332. Alaska Airlines is 44% 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 (94%), Alaska Airlines (84%) and American Airlines (83%).

  • 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$ 332). Flying from Seattle to St. Louis in December is currently the most expensive (average of C$ 785). 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

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Top airline flying from Seattle to St. Louis

AirlineCheapestAverageFlexibilityOn-time
Alaska AirlinesCheapestC$ 332AverageC$ 514FlexibilityNo cancel feeOn-time75%
Search Alaska Airlines flights

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