$109+ Cheap flights from St. Louis to Seattle (STL - SEA)
This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 10/24. Fares are subject to change and may not be available on all flights or dates of travel.
STL — SEA
Oct 25 — Nov 11
Round-trip
1 adult, Economy
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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 February or March, booked 44 days in advance, depart on a Friday or Saturday and return on a Thursday
Cheap flight deals from St. Louis to Seattle
Cheapest
Best
Last-minute
One-way
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 September 25, 2026.
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 September 25, 2026.
This Southwest deal was found by Cheapflights users on 9/21. 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.
Sat 12/125:50 am -
1 stop7h 00m
Tue 12/159:25 am -
1 stop7h 10m
Deal found 9/21![Southwest logo]()
$212
This Delta deal was found by Cheapflights users on 9/21. 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.
Sat 10/243:35 pm -
1 stop7h 15m
Sat 10/315:30 am -
1 stop6h 02m
Deal found 9/21![Delta logo]()
$217
This Southwest deal was found by Cheapflights users on 9/20. 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.
Tue 10/205:20 am -
2 stops10h 15m
Tue 10/273:30 pm -
1 stop5h 45m
Deal found 9/20![Southwest logo]()
$222
This American Airlines deal was found by Cheapflights users on 9/24. 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.
Fri 11/67:26 am -
1 stop8h 54m
Sun 11/83:10 pm -
1 stop6h 45m
Deal found 9/24![American Airlines logo]()
$226
This Southwest deal was found by Cheapflights users on 9/22. 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.
Fri 11/67:15 pm -
1 stop7h 30m
Thu 11/1212:15 am -
1 stop7h 50m
Deal found 9/22![Southwest logo]()
$227
This Southwest deal was found by Cheapflights users on 9/23. 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.
Sat 10/248:25 am -
2 stops13h 40m
Sat 10/317:40 am -
1 stop9h 05m
Deal found 9/23![Southwest logo]()
$228
This Southwest deal was found by Cheapflights users on 9/22. 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.
Fri 10/232:25 pm -
1 stop8h 10m
Mon 10/266:50 pm -
1 stop13h 00m
Deal found 9/22![Southwest logo]()
$232
This Southwest deal was found by Cheapflights users on 9/24. 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.
Mon 11/27:15 pm -
1 stop7h 25m
Tue 11/35:15 am -
2 stops13h 50m
Deal found 9/24![Southwest logo]()
$233
This Southwest deal was found by Cheapflights users on 9/21. 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.
Fri 10/305:50 pm -
2 stops8h 50m
Mon 11/211:20 am -
2 stops11h 30m
Deal found 9/21![Southwest logo]()
$237
This American Airlines deal was found by Cheapflights users on 9/23. 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.
Sun 10/255:40 am -
1 stop7h 34m
Tue 10/276:12 am -
1 stop8h 41m
Deal found 9/23![American Airlines logo]()
$257
Best flights from St. Louis to SeattleDiscover 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 September 25, 2026.
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 September 25, 2026.
This Southwest deal was found by Cheapflights users on 9/21. 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.
Thu 11/59:45 pm -
1 stop12h 40m
Sun 11/811:20 am -
2 stops11h 35m
Deal found 9/21![Southwest logo]()
$343
This United Airlines deal was found by Cheapflights users on 9/22. 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.
Thu 10/228:00 am -
1 stop9h 51m
Thu 10/297:35 pm -
2 stops12h 57m
Deal found 9/22![United Airlines logo]()
$352
This Alaska Airlines deal was found by Cheapflights users on 9/24. 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.
Mon 11/26:00 am -
Nonstop4h 36m
Tue 11/38:22 am -
Nonstop4h 03m
Deal found 9/24![Alaska Airlines logo]()
$397
This American Airlines deal was found by Cheapflights users on 9/24. 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.
Fri 11/66:00 am -
Nonstop4h 36m
Sun 11/88:22 am -
Nonstop4h 03m
Deal found 9/24![Multiple Airlines logo]()
$496
This Southwest deal was found by Cheapflights users on 9/21. 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.
Fri 12/258:25 am -
2 stops12h 35m
Sun 1/106:35 am -
1 stop8h 00m
Deal found 9/21![Southwest logo]()
$348
This United Airlines deal was found by Cheapflights users on 9/24. 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.
Mon 11/21:08 pm -
1 stop7h 55m
Tue 11/311:15 pm -
1 stop9h 33m
Deal found 9/24![United Airlines logo]()
$417
This Alaska Airlines deal was found by Cheapflights users on 9/21. 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.
Fri 2/123:24 pm -
Nonstop4h 28m
Sun 2/145:50 pm -
Nonstop3h 54m
Deal found 9/21![Alaska Airlines logo]()
$447
This United Airlines deal was found by Cheapflights users on 9/23. 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.
Fri 10/238:00 am -
2 stops14h 37m
Sun 10/257:00 am -
1 stop6h 43m
Deal found 9/23![United Airlines logo]()
$448
This Alaska Airlines deal was found by Cheapflights users on 9/22. 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.
Tue 10/137:02 am -
Nonstop4h 33m
Sun 10/256:03 pm -
Nonstop3h 56m
Deal found 9/22![Alaska Airlines logo]()
$487
This United Airlines deal was found by Cheapflights users on 9/24. 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.
Fri 10/239:04 am -
2 stops13h 33m
Mon 10/2611:59 pm -
1 stop8h 03m
Deal found 9/24![United Airlines logo]()
$452
This Alaska Airlines deal was found by Cheapflights users on 9/23. 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.
Tue 10/134:42 pm -
Nonstop4h 28m
Tue 10/276:03 pm -
Nonstop3h 56m
Deal found 9/23![Alaska Airlines logo]()
$497
This United Airlines deal was found by Cheapflights users on 9/25. 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.
Thu 1/71:09 pm -
2 stops11h 29m
Mon 1/187:00 am -
1 stop27h 13m
Deal found 9/25![United Airlines logo]()
$495
Last-minute flights from St. Louis to SeattleDiscover last-minute flight deals from St. Louis to Seattle. Data last updated September 25, 2026 and is based on user searches.
Discover last-minute flight deals from St. Louis to Seattle. Data last updated September 25, 2026 and is based on user searches.
This Cheapflightsfares deal was found by Cheapflights users on 9/21. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/144:19 pm -
1 stop24h 53m
Wed 10/2812:14 pm -
1 stop22h 19m
Deal found 9/21![Frontier logo]()
$284
This Southwest deal was found by Cheapflights users on 9/20. 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.
Tue 10/205:20 am -
2 stops10h 15m
Tue 10/273:30 pm -
1 stop5h 45m
Deal found 9/20![Southwest logo]()
$222
This Southwest deal was found by Cheapflights users on 9/21. 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.
Fri 10/232:25 pm -
2 stops10h 10m
Tue 10/2712:10 am -
1 stop7h 15m
Deal found 9/21![Southwest logo]()
$227
This Southwest deal was found by Cheapflights users on 9/22. 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.
Fri 10/232:25 pm -
1 stop8h 10m
Mon 10/266:50 pm -
1 stop13h 00m
Deal found 9/22![Southwest logo]()
$232
This Delta deal was found by Cheapflights users on 9/21. 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.
Sat 10/243:35 pm -
1 stop7h 15m
Sat 10/315:30 am -
1 stop6h 02m
Deal found 9/21![Delta logo]()
$217
This Southwest deal was found by Cheapflights users on 9/23. 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.
Sat 10/248:25 am -
2 stops13h 40m
Sat 10/317:40 am -
1 stop9h 05m
Deal found 9/23![Southwest logo]()
$228
This American Airlines deal was found by Cheapflights users on 9/23. 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.
Sun 10/255:40 am -
1 stop7h 34m
Tue 10/276:12 am -
1 stop8h 41m
Deal found 9/23![American Airlines logo]()
$257
This Southwest deal was found by Cheapflights users on 9/22. 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.
Fri 10/302:25 pm -
2 stops10h 10m
Mon 11/211:20 am -
2 stops11h 30m
Deal found 9/22![Southwest logo]()
$237
One-way flights from St. Louis to SeattleSearch for one-way flight options from St. Louis to Seattle. Find affordable one-way fares based on user searches. Data last updated September 25, 2026.
Search for one-way flight options from St. Louis to Seattle. Find affordable one-way fares based on user searches. Data last updated September 25, 2026.
This Delta deal was found by Cheapflights users on 9/25. 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.
Sat 10/247:45 am -
1 stop9h 05m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/25![Delta logo]()
$109
This Delta deal was found by Cheapflights users on 9/24. 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.
Sun 11/225:22 pm -
1 stop8h 35m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/24![Delta logo]()
$114
This Southwest deal was found by Cheapflights users on 9/21. 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.
Fri 10/232:25 pm -
2 stops10h 10m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/21![Southwest logo]()
$119
This Southwest deal was found by Cheapflights users on 9/25. 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.
Sat 10/248:25 am -
2 stops13h 40m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/25![Southwest logo]()
$120
This American Airlines deal was found by Cheapflights users on 9/21. 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.
Tue 12/16:00 am -
1 stop10h 25m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/21![American Airlines logo]()
$140
This Super.com deal was found by Cheapflights users on 9/21. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/191:28 pm -
1 stop25h 09m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/21![Frontier logo]()
$148
This Kiwi.com deal was found by Cheapflights users on 9/23. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/233:04 pm -
1 stop26h 18m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/23![Frontier logo]()
$153
This Kiwi.com deal was found by Cheapflights users on 9/23. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/268:00 pm -
2 stops48h 54m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/23![Frontier logo]()
$155
This United Airlines deal was found by Cheapflights users on 9/21. 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.
Tue 11/38:50 am -
2 stops9h 37m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/21![United Airlines logo]()
$156
This Kiwi.com deal was found by Cheapflights users on 9/21. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/184:18 pm -
2 stops19h 27m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/21![Frontier logo]()
$162
Find 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 September 25, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $212 (Southwest) |
One-way from | $109 (Delta) |
Popular in | July |
Cheapest in | February |
Average price | $378 |
Good round-trip deal | $425 or less |
Good one-way deal | $253 or less |
Cheapflights Fare Finder
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 7,457,451 searches. Data last updated September 25, 2026.
Use the filters below to find and compare flights from St. Louis to Seattle that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
St. LouisSeattle
STL Lambert-St Louis - SEA Seattle/Tacoma Intl
STLSEA
Lambert-St Louis
Mon 11/23
7:00 pm-11:59 pm
1 stop6h 59m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-2:00 am
Nonstop0h 00m
$114
St. LouisSeattle
STL Lambert-St Louis - SEA Seattle/Tacoma Intl
STLSEA
Lambert-St Louis
Mon 10/26
7:05 pm-12:59 am
1 stop7h 54m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-2:00 am
Nonstop0h 00m
$114
St. LouisSeattle
STL Lambert-St Louis - SEA Seattle/Tacoma Intl
STLSEA
Lambert-St Louis
Sun 11/1
8:00 am-4:27 pm
1 stop10h 27m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-2:00 am
Nonstop0h 00m
$114
St. LouisSeattle
STL Lambert-St Louis - SEA Seattle/Tacoma Intl
STLSEA
Lambert-St Louis
Wed 12/23
6:09 pm-11:16 pm
1 stop7h 07m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-2:00 am
Nonstop0h 00m
$174
St. LouisSeattle
STL Lambert-St Louis - SEA Seattle/Tacoma Intl
STLSEA
Lambert-St Louis
Mon 11/23
10:53 am-9:50 pm
2 stops12h 57m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-2:00 am
Nonstop0h 00m
$179
St. LouisSeattle
STL Lambert-St Louis - SEA Seattle/Tacoma Intl
STLSEA
Lambert-St Louis
Tue 10/20
6:30 am-1:35 pm
2 stops9h 05m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-2:00 am
Nonstop0h 00m
$209
St. LouisSeattle
STL Lambert-St Louis - SEA Seattle/Tacoma Intl
STLSEA
Lambert-St Louis
Wed 12/2
10:21 am-9:57 pm
2 stops13h 36m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-2:00 am
Nonstop0h 00m
$219
St. LouisSeattle
STL Lambert-St Louis - SEA Seattle/Tacoma Intl
STLSEA
Lambert-St Louis
Wed 11/25
6:00 am-8:40 am
Nonstop4h 40m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-2:00 am
Nonstop0h 00m
$224
St. LouisSeattle
STL Lambert-St Louis - SEA Seattle/Tacoma Intl
STLSEA
Lambert-St Louis
Fri 11/20
6:00 am-8:40 am
Nonstop4h 40m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-2:00 am
Nonstop0h 00m
$224
Quickest round-trip
St. LouisSeattle
STL Lambert-St Louis - SEA Seattle/Tacoma Intl
STLSEA
Lambert-St Louis
Fri 10/23
7:02 am-9:35 am
Nonstop4h 33m
Seattle/Tacoma Intl
Wed 12/31
12:00 am-2:00 am
Nonstop0h 00m
$224
Showing 1-10 of 23 resultsSorted by cheapest first
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 September.
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy- | Trust Score*1 star | |
| Price Accuracy1 star | Trust Score*3 stars |
- 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.
STL-SEA
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
More
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 43 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, February is the cheapest month in which you can book a flight from St. Louis to Seattle (average of $237). Flying from St. Louis to Seattle in July is currently the most expensive (average of $522). 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 September 25, 2026.
Unlike at noon, when flights are generally more expensive, you can save up to 15% on flights from St. Louis to Seattle by exploring options for tickets in the evening.
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 September 19, 2026.
Travelers seeking maximum savings on their St. Louis to Seattle flight should consider departing on Saturday afternoons when fares are most often at their lowest. Wednesday at noon flights should be avoided if possible as fares are typically the most expensive at this time.
What’s the top layover airport for flights from St. Louis to Seattle?
Share of 1-stop round-trip flights from St. Louis to Seattle chosen by Cheapflights users in the past 12 months, using the same layover each way.
Chicago (ORD) – chosen by Cheapflights users on 25% of 1-stop itineraries from St. Louis to Seattle on Cheapflights.
What’s the cheapest layover airport for flights from St. Louis to Seattle?
Average round-trip fare for 1-stop flights from St. Louis to Seattle, chosen by Cheapflights users in the past 12 months, with the same layover each way.
Denver (DEN) is the most affordable 1-stop option, with an average round-trip price of $248.
What’s the fastest layover option from St. Louis to Seattle?
Shortest average travel time for 1-stop one-way flights from St. Louis to Seattle, based on itineraries clicked by Cheapflights users over the past 12 months, grouped by layover airport.
Flights via Chicago (ORD) have the shortest average one-way travel time for 1-stop routes: 7h 15m.
Which airport typically offers the quickest layover for flights from St. Louis to Seattle?
Average layover duration for 1-stop one-way flights from St. Louis to Seattle, chosen by Cheapflights users in the last 12 months, grouped by stopover airport.
Flights via Chicago (ORD) offer the fastest connection on this route, with an average layover time of 0h 56m.
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
Our travel experts
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 September 25, 2026.
Read through reviews of airlines operating flights from St. Louis to Seattle, such as Southwest,Alaska Airlines, andDelta. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Boarding
8.1
Comfort
8.0
Crew
8.6
Entertainment
7.5
Food
7.0
Overall
8.0
Reviews
1 / 20
4.0
OkaySteven,Sep 2026
OGG - HNL
Boarding
8.1
Comfort
8.0
Crew
8.6
Entertainment
7.5
Food
7.0
Overall
8.0
Reviews
1 / 20
4.0
OkaySteven,Sep 2026
OGG - HNL
Boarding
8.1
Comfort
8.0
Crew
8.6
Entertainment
7.5
Food
7.0
Overall
8.0
Reviews
1 / 20
4.0
OkaySteven,Sep 2026
OGG - HNL
Boarding
8.1
Comfort
8.0
Crew
8.6
Entertainment
7.5
Food
7.0
Overall
8.0
Reviews
1 / 20
4.0
OkaySteven,Sep 2026
OGG - HNL
Boarding
8.1
Comfort
8.0
Crew
8.6
Entertainment
7.5
Food
7.0
Overall
8.0
Reviews
1 / 20
4.0
OkaySteven,Sep 2026
OGG - HNL
Boarding
8.1
Comfort
8.0
Crew
8.6
Entertainment
7.5
Food
7.0
Overall
8.0
Reviews
1 / 20
4.0
OkaySteven,Sep 2026
OGG - HNL
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.
Traveling to a place near Seattle?
Book flights to Seattle if you plan to visit one of these locationsSeaTac
Renton
Tacoma
Lacey
Leavenworth
Olympia
Tukwila
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Puyallup
Lynnwood
Centralia
Kent
Tumwater
Ellensburg
Issaquah
Marysville
Ocean Shores
Lakewood
Fife
Poulsbo
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St. Louis and Seattle flights
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Top 6 airlines flying from St. Louis to Seattle
Discover the top 6 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 7,457,451 searches. Data last updated September 25, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$129 | Average$281 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$134 | Average$248 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$177 | Average$411 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$186 | Average$389 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$219 | Average$388 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$219 | Average$422 | FlexibilityNo cancel fee | On-time75% |