$125+ 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 8/20. Fares are subject to change and may not be available on all flights or dates of travel.
STL — SEA
Jul 25 — Aug 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 November, booked 56 days in advance, depart on a Thursday or Tuesday and return on a Tuesday
Cheap flight deals from St. Louis to Seattle
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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 June 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 June 25, 2026.
This Kiwi.com deal was found by Cheapflights users on 6/25. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/177:10 pm
STL
- SEA
1 stop17h 29m
Multiple Airlines
Tue 7/287:55 am
SEA
- STL
Nonstop3h 57m
Multiple Airlines
Deal found 6/25![Multiple Airlines logo]()
$391
This Southwest deal was found by Cheapflights users on 6/25. 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.
Tue 7/286:10 am
STL
- SEA
2 stops9h 25m
Southwest
Tue 8/411:05 pm
SEA
- STL
1 stop8h 30m
Southwest
Deal found 6/25![Southwest logo]()
$392
This Kiwi.com deal was found by Cheapflights users on 6/25. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 6/267:38 pm
STL
- SEA
1 stop16h 10m
Multiple Airlines
Wed 7/156:04 pm
SEA
- STL
Nonstop3h 55m
Multiple Airlines
Deal found 6/25![Multiple Airlines logo]()
$393
This Kiwi.com deal was found by Cheapflights users on 6/25. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 7/208:08 pm
STL
- SEA
1 stop15h 09m
Multiple Airlines
Fri 7/246:04 pm
SEA
- STL
Nonstop3h 55m
Multiple Airlines
Deal found 6/25![Multiple Airlines logo]()
$394
This Kiwi.com deal was found by Cheapflights users on 6/21. 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.
Thu 7/167:10 pm
STL
- SEA
1 stop17h 29m
Frontier
Thu 7/237:06 pm
SEA
- STL
2 stops11h 51m
Frontier
Deal found 6/21![Frontier logo]()
$395
This Kiwi.com deal was found by Cheapflights users on 6/22. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 7/208:08 pm
STL
- SEA
1 stop15h 09m
Multiple Airlines
Thu 7/236:04 pm
SEA
- STL
Nonstop3h 55m
Multiple Airlines
Deal found 6/22![Multiple Airlines logo]()
$396
This CheapOair deal was found by Cheapflights users on 6/24. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/112:50 pm
STL
- SEA
Nonstop4h 27m
Alaska Airlines
Thu 8/276:03 pm
SEA
- STL
Nonstop3h 56m
Alaska Airlines
Deal found 6/24![Alaska Airlines logo]()
$397
This Kiwi.com deal was found by Cheapflights users on 6/23. 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.
Sun 7/58:08 pm
STL
- SEA
1 stop17h 12m
Multiple Airlines
Tue 7/76:04 pm
SEA
- STL
Nonstop3h 55m
Multiple Airlines
Deal found 6/23![Multiple Airlines logo]()
$398
This Kiwi.com deal was found by Cheapflights users on 6/20. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 6/277:38 pm
STL
- SEA
1 stop16h 10m
Multiple Airlines
Sat 7/41:06 pm
SEA
- STL
Nonstop3h 51m
Multiple Airlines
Deal found 6/20![Multiple Airlines logo]()
$399
This Kiwi.com deal was found by Cheapflights users on 6/23. 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.
Tue 6/308:08 pm
STL
- SEA
1 stop15h 40m
Frontier
Wed 7/88:13 pm
SEA
- STL
1 stop20h 02m
Frontier
Deal found 6/23![Frontier logo]()
$400
This Kiwi.com deal was found by Cheapflights users on 6/23. 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.
Wed 7/18:08 pm
STL
- SEA
1 stop15h 40m
Frontier
Fri 7/317:06 pm
SEA
- STL
2 stops11h 51m
Frontier
Deal found 6/23![Frontier logo]()
$401
This Southwest deal was found by Cheapflights users on 6/23. 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.
Mon 8/108:30 am
STL
- SEA
2 stops8h 25m
Southwest
Wed 8/196:25 am
SEA
- STL
1 stop6h 40m
Southwest
Deal found 6/23![Southwest logo]()
$402
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 June 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 June 25, 2026.
This Delta deal was found by Cheapflights users on 6/24. 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.
Fri 8/2110:33 am
STL
- SEA
1 stop10h 12m
Delta
Fri 8/2111:59 pm
SEA
- STL
1 stop8h 24m
Delta
Deal found 6/24![Delta logo]()
$417
This Southwest deal was found by Cheapflights users on 6/24. 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.
Thu 8/201:45 pm
STL
- SEA
2 stops9h 30m
Southwest
Mon 8/246:15 am
SEA
- STL
2 stops11h 45m
Southwest
Deal found 6/24![Southwest logo]()
$427
This United Airlines deal was found by Cheapflights users on 6/21. 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.
Wed 9/28:00 am
STL
- SEA
2 stops13h 08m
United Airlines
Sat 9/511:59 pm
SEA
- STL
1 stop8h 11m
United Airlines
Deal found 6/21![United Airlines logo]()
$433
This Alaska Airlines deal was found by Cheapflights users on 6/24. 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.
Sat 9/1910:14 am
STL
- SEA
2 stops10h 38m
Alaska Airlines
Mon 9/2111:41 am
SEA
- STL
1 stop9h 59m
Alaska Airlines
Deal found 6/24![Alaska Airlines logo]()
$482
This United Airlines deal was found by Cheapflights users on 6/20. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/188:00 am
STL
- SEA
2 stops13h 08m
United Airlines
Wed 8/1911:59 pm
SEA
- STL
1 stop8h 11m
United Airlines
Deal found 6/20![United Airlines logo]()
$434
This Southwest deal was found by Cheapflights users on 6/24. 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.
Wed 8/55:35 am
STL
- SEA
1 stop6h 55m
Southwest
Wed 8/510:30 pm
SEA
- STL
2 stops14h 40m
Southwest
Deal found 6/24![Southwest logo]()
$468
This Alaska Airlines deal was found by Cheapflights users on 6/21. 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.
Tue 9/810:16 am
STL
- SEA
2 stops10h 36m
Alaska Airlines
Thu 9/108:40 am
SEA
- STL
1 stop9h 05m
Alaska Airlines
Deal found 6/21![Alaska Airlines logo]()
$482
This Southwest deal was found by Cheapflights users on 6/24. 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.
Fri 9/46:25 pm
STL
- SEA
1 stop7h 55m
Southwest
Sun 9/136:55 am
SEA
- STL
2 stops9h 15m
Southwest
Deal found 6/24![Southwest logo]()
$477
This Southwest deal was found by Cheapflights users on 6/20. 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.
Fri 8/78:25 am
STL
- SEA
Nonstop4h 20m
Southwest
Sun 8/99:25 pm
SEA
- STL
1 stop10h 25m
Southwest
Deal found 6/20![Southwest logo]()
$498
This Alaska Airlines deal was found by Cheapflights users on 6/22. 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.
Mon 7/207:56 pm
STL
- SEA
Nonstop4h 28m
Alaska Airlines
Mon 7/2711:26 pm
SEA
- STL
1 stop15h 11m
Alaska Airlines
Deal found 6/22![Alaska Airlines logo]()
$550
This Alaska Airlines deal was found by Cheapflights users on 6/20. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/101:27 pm
STL
- SEA
1 stop10h 07m
Alaska Airlines
Fri 7/176:04 pm
SEA
- STL
Nonstop3h 55m
Alaska Airlines
Deal found 6/20![Alaska Airlines logo]()
$582
Last-minute flights from St. Louis to SeattleDiscover last-minute flight deals from St. Louis to Seattle. Data last updated June 25, 2026 and is based on user searches.
Discover last-minute flight deals from St. Louis to Seattle. Data last updated June 25, 2026 and is based on user searches.
This Kiwi.com deal was found by Cheapflights users on 6/25. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 6/267:38 pm
STL
- SEA
1 stop16h 10m
Multiple Airlines
Wed 7/156:04 pm
SEA
- STL
Nonstop3h 55m
Multiple Airlines
Deal found 6/25![Multiple Airlines logo]()
$393
This Kiwi.com deal was found by Cheapflights users on 6/23. 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 6/297:38 pm
STL
- SEA
1 stop16h 10m
Multiple Airlines
Wed 7/86:04 pm
SEA
- STL
Nonstop3h 55m
Multiple Airlines
Deal found 6/23![Multiple Airlines logo]()
$399
This Kiwi.com deal was found by Cheapflights users on 6/23. 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.
Tue 6/308:08 pm
STL
- SEA
1 stop15h 40m
Multiple Airlines
Tue 7/76:04 pm
SEA
- STL
Nonstop3h 55m
Multiple Airlines
Deal found 6/23![Multiple Airlines logo]()
$397
This Kiwi.com deal was found by Cheapflights users on 6/23. 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.
Tue 6/308:08 pm
STL
- SEA
1 stop15h 40m
Frontier
Wed 7/88:13 pm
SEA
- STL
1 stop20h 02m
Frontier
Deal found 6/23![Frontier logo]()
$400
This Kiwi.com deal was found by Cheapflights users on 6/23. 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.
Wed 7/18:08 pm
STL
- SEA
1 stop15h 40m
Frontier
Fri 7/317:06 pm
SEA
- STL
2 stops11h 51m
Frontier
Deal found 6/23![Frontier logo]()
$401
This Kiwi.com deal was found by Cheapflights users on 6/23. 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.
Sun 7/58:08 pm
STL
- SEA
1 stop17h 12m
Multiple Airlines
Tue 7/76:04 pm
SEA
- STL
Nonstop3h 55m
Multiple Airlines
Deal found 6/23![Multiple Airlines logo]()
$398
This Southwest deal was found by Cheapflights users on 6/23. 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.
Tue 7/76:10 am
STL
- SEA
2 stops9h 25m
Southwest
Wed 7/86:30 am
SEA
- STL
1 stop7h 50m
Southwest
Deal found 6/23![Southwest logo]()
$402
This Kiwi.com deal was found by Cheapflights users on 6/21. 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.
Thu 7/167:10 pm
STL
- SEA
1 stop17h 29m
Frontier
Thu 7/237:06 pm
SEA
- STL
2 stops11h 51m
Frontier
Deal found 6/21![Frontier logo]()
$395
This Kiwi.com deal was found by Cheapflights users on 6/25. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/177:10 pm
STL
- SEA
1 stop17h 29m
Multiple Airlines
Tue 7/287:55 am
SEA
- STL
Nonstop3h 57m
Multiple Airlines
Deal found 6/25![Multiple Airlines logo]()
$391
This Kiwi.com deal was found by Cheapflights users on 6/25. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 7/208:08 pm
STL
- SEA
1 stop15h 09m
Multiple Airlines
Fri 7/246:04 pm
SEA
- STL
Nonstop3h 55m
Multiple Airlines
Deal found 6/25![Multiple Airlines logo]()
$394
This Kiwi.com deal was found by Cheapflights users on 6/22. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 7/208:08 pm
STL
- SEA
1 stop15h 09m
Multiple Airlines
Thu 7/236:04 pm
SEA
- STL
Nonstop3h 55m
Multiple Airlines
Deal found 6/22![Multiple Airlines logo]()
$396
This Southwest deal was found by Cheapflights users on 6/25. 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.
Tue 7/286:10 am
STL
- SEA
2 stops9h 25m
Southwest
Tue 8/411:05 pm
SEA
- STL
1 stop8h 30m
Southwest
Deal found 6/25![Southwest logo]()
$392
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 June 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 June 25, 2026.
This Kiwi.com deal was found by Cheapflights users on 6/21. 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.
Thu 8/206:45 pm
STL
- SEA
1 stop17h 54m
Frontier
Deal found 6/21![Frontier logo]()
$125
This Kiwi.com deal was found by Cheapflights users on 6/21. 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.
Mon 7/207:10 pm
STL
- SEA
2 stops24h 41m
Frontier
Deal found 6/21![Frontier logo]()
$126
This Kiwi.com deal was found by Cheapflights users on 6/22. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/188:00 am
STL
- SEA
2 stops35h 51m
Frontier
Deal found 6/22![Frontier logo]()
$127
This Kiwi.com deal was found by Cheapflights users on 6/24. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/196:45 pm
STL
- SEA
1 stop17h 54m
Frontier
Deal found 6/24![Frontier logo]()
$128
This Super.com deal was found by Cheapflights users on 6/21. 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.
Tue 7/147:03 pm
STL
- SEA
1 stop17h 36m
Frontier
Deal found 6/21![Frontier logo]()
$129
This Super.com deal was found by Cheapflights users on 6/24. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/107:10 pm
STL
- SEA
1 stop17h 29m
Frontier
Deal found 6/24![Frontier logo]()
$130
This Super.com deal was found by Cheapflights users on 6/23. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/78:08 pm
STL
- SEA
1 stop15h 09m
Frontier
Deal found 6/23![Frontier logo]()
$131
This Super.com deal was found by Cheapflights users on 6/21. 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 7/97:10 pm
STL
- SEA
1 stop17h 29m
Frontier
Deal found 6/21![Frontier logo]()
$132
This Trip.com deal was found by Cheapflights users on 6/23. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/88:08 pm
STL
- SEA
1 stop14h 56m
Frontier
Deal found 6/23![Frontier logo]()
$134
This CheapOair deal was found by Cheapflights users on 6/24. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/1912:46 pm
STL
- SEA
1 stop23h 14m
Frontier
Deal found 6/24![Frontier logo]()
$135
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 June 25, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $392 (Kiwi.com) |
One-way from | $125 (Kiwi.com) |
Popular in | July |
Cheapest in | February |
Average price | $464 |
Good round-trip deal | $474 or less |
Good one-way deal | $273 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 2,558,603 searches. Data last updated June 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 - SEA
STLSEA
Lambert-St Louis
Fri 8/21
10:33 am-6:45 pm
1 stop10h 12m
Seattle/Tacoma Intl
Fri 8/21
11:59 pm-10:23 am
1 stop8h 24m
$417
St. LouisSeattle
STL - SEA
STLSEA
Lambert-St Louis
Thu 8/20
1:45 pm-9:15 pm
2 stops9h 30m
Seattle/Tacoma Intl
Mon 8/24
6:15 am-8:00 pm
2 stops11h 45m
$427
St. LouisSeattle
STL - SEA
STLSEA
Lambert-St Louis
Wed 9/2
8:00 am-7:08 pm
2 stops13h 08m
Seattle/Tacoma Intl
Sat 9/5
11:59 pm-10:10 am
1 stop8h 11m
$433
St. LouisSeattle
STL - SEA
STLSEA
Lambert-St Louis
Tue 8/18
8:00 am-7:08 pm
2 stops13h 08m
Seattle/Tacoma Intl
Wed 8/19
11:59 pm-10:10 am
1 stop8h 11m
$434
St. LouisSeattle
STL - SEA
STLSEA
Lambert-St Louis
Wed 8/5
5:35 am-10:30 am
1 stop6h 55m
Seattle/Tacoma Intl
Wed 8/5
10:30 pm-3:10 pm
2 stops14h 40m
$468
St. LouisSeattle
STL - SEA
STLSEA
Lambert-St Louis
Fri 9/4
6:25 pm-12:20 am
1 stop7h 55m
Seattle/Tacoma Intl
Sun 9/13
6:55 am-6:10 pm
2 stops9h 15m
$477
St. LouisSeattle
STL - SEA
STLSEA
Lambert-St Louis
Sat 9/19
10:14 am-6:52 pm
2 stops10h 38m
Seattle/Tacoma Intl
Mon 9/21
11:41 am-11:40 pm
1 stop9h 59m
$482
St. LouisSeattle
STL - SEA
STLSEA
Lambert-St Louis
Tue 9/8
10:16 am-6:52 pm
2 stops10h 36m
Seattle/Tacoma Intl
Thu 9/10
8:40 am-7:45 pm
1 stop9h 05m
$482
St. LouisSeattle
STL - SEA
STLSEA
Lambert-St Louis
Fri 8/7
8:25 am-10:45 am
Nonstop4h 20m
Seattle/Tacoma Intl
Sun 8/9
9:25 pm-9:50 am
1 stop10h 25m
$498
St. LouisSeattle
STL - SEA
STLSEA
Lambert-St Louis
Mon 7/20
7:56 pm-10:24 pm
Nonstop4h 28m
Seattle/Tacoma Intl
Mon 7/27
11:26 pm-4:37 pm
1 stop15h 11m
$550
Showing 1-10 of 22 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 June.
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy- | Trust Score*1 star |
- 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
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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 55 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 $475). 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 June 25, 2026.
Unlike at noon, when flights are generally more expensive, you can save up to 12% 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?
Use this chart to determine the cheapest time to fly round-trip from St. Louis to Seattle. Price data was last updated on June 20, 2026.
Travelers seeking maximum savings on their St. Louis to Seattle flight should consider departing on Sunday 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.
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.
Denver (DEN) – chosen by Cheapflights users on 50% 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 Las Vegas (LAS) have the shortest average one-way travel time for 1-stop routes: 8h 16m.
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 Las Vegas (LAS) offer the fastest connection on this route, with an average layover time of 1h 57m.
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 June 25, 2026.
Read through reviews of airlines operating flights from St. Louis to Seattle, such as Alaska Airlines,Southwest, andDelta. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Comfort
7.8
Crew
8.5
Entertainment
7.0
Food
7.0
Overall
7.9
Boarding
8.1
Reviews
1 / 20
8.0
ExcellentAnonymous,Jun 2026
RDU - SEA
Comfort
7.8
Crew
8.5
Entertainment
7.0
Food
7.0
Overall
7.9
Boarding
8.1
Reviews
1 / 20
8.0
ExcellentAnonymous,Jun 2026
RDU - SEA
Comfort
7.8
Crew
8.5
Entertainment
7.0
Food
7.0
Overall
7.9
Boarding
8.1
Reviews
1 / 20
8.0
ExcellentAnonymous,Jun 2026
RDU - SEA
Comfort
7.8
Crew
8.5
Entertainment
7.0
Food
7.0
Overall
7.9
Boarding
8.1
Reviews
1 / 20
8.0
ExcellentAnonymous,Jun 2026
RDU - SEA
Comfort
7.8
Crew
8.5
Entertainment
7.0
Food
7.0
Overall
7.9
Boarding
8.1
Reviews
1 / 20
8.0
ExcellentAnonymous,Jun 2026
RDU - SEA
Comfort
7.8
Crew
8.5
Entertainment
7.0
Food
7.0
Overall
7.9
Boarding
8.1
Reviews
1 / 20
8.0
ExcellentAnonymous,Jun 2026
RDU - SEA
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
Tacoma
Lacey
Leavenworth
Olympia
Ocean Shores
Renton
Edmonds
Snoqualmie
Tumwater
Tukwila
Kent
Lynnwood
Ellensburg
Fife
Marysville
Lakewood
Issaquah
Shoreline
Centralia
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St. Louis and Seattle flights
Browse other St. Louis and Seattle flight options. Last updated on June 25, 2026.
Other flights from St. Louis
Browse through other flights departing from St. Louis. Flights are based on user searches made on Cheapflights and were last updated on June 25, 2026.
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Explore flights to Seattle departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on June 25, 2026.
Top 7 airlines flying from St. Louis to Seattle
Discover the top 7 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 2,558,603 searches. Data last updated June 25, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$129 | Average$266 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$136 | Average$247 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$178 | Average$388 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$179 | Average$408 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$188 | Average$398 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$217 | Average$386 | FlexibilityNo cancel fee | On-time75% | |
| Cheapest$222 | Average$329 | FlexibilityNo cancel fee | On-time85% |