$104+ Cheap flights from Seattle (SEA) to St. Charles, MO
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 11/7. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — STL
Sep 8 — Sep 151
Round-trip
1 adult, Economy
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Find cheap flights from Seattle to St. Charles 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 Seattle/Tacoma Intl to St. Charles are usually found in January or February, booked 77 days in advance, depart on a Tuesday or Thursday and return on a Friday
Cheap flight deals from Seattle to St. Charles
Cheapest
Best
Last-minute
One-way
Cheapest flights from Seattle to St. CharlesExplore the most affordable flight options available from Seattle to St. Charles. Find the lowest fares from popular airlines and budget airlines, with prices last updated on August 9, 2026.
Explore the most affordable flight options available from Seattle to St. Charles. Find the lowest fares from popular airlines and budget airlines, with prices last updated on August 9, 2026.
This Kiwi.com deal was found by Cheapflights users on 8/8. 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 9/87:06 pm -
1 stop22h 11m
Mon 9/148:10 pm -
1 stop20h 58m
Deal found 8/8![Frontier logo]()
$286
This Frontier deal was found by Cheapflights users on 8/5. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/139:45 pm -
1 stop11h 32m
Mon 9/2112:17 pm -
1 stop8h 11m
Deal found 8/5![Frontier logo]()
$288
This Kiwi.com deal was found by Cheapflights users on 8/7. 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 8/277:06 pm -
2 stops20h 16m
Mon 8/317:58 pm -
1 stop15h 21m
Deal found 8/7![Frontier logo]()
$289
This Southwest deal was found by Cheapflights users on 8/5. 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 9/161:45 pm -
1 stop6h 55m
Wed 9/2311:55 am -
2 stops10h 25m
Deal found 8/5![Southwest logo]()
$293
This Kiwi.com deal was found by Cheapflights users on 8/6. 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 10/227:41 pm -
1 stop21h 34m
Mon 10/268:10 pm -
1 stop15h 41m
Deal found 8/6![Frontier logo]()
$294
This Kiwi.com deal was found by Cheapflights users on 8/6. 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 8/267:06 pm -
2 stops19h 05m
Mon 8/317:58 pm -
1 stop15h 21m
Deal found 8/6![Frontier logo]()
$296
This Southwest deal was found by Cheapflights users on 8/5. 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 10/226:50 pm -
1 stop13h 10m
Sun 10/256:20 am -
1 stop6h 10m
Deal found 8/5![Southwest logo]()
$298
This Kiwi.com deal was found by Cheapflights users on 8/4. 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 10/147:41 pm -
1 stop21h 34m
Mon 10/268:10 pm -
1 stop15h 41m
Deal found 8/4![Frontier logo]()
$300
This Kiwi.com deal was found by Cheapflights users on 8/6. 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 8/292:37 pm -
2 stops23h 34m
Mon 8/317:58 pm -
1 stop15h 21m
Deal found 8/6![Frontier logo]()
$301
This Southwest deal was found by Cheapflights users on 8/8. 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 9/1012:50 pm -
2 stops9h 50m
Tue 9/158:25 am -
2 stops10h 25m
Deal found 8/8![Southwest logo]()
$303
This Kiwi.com deal was found by Cheapflights users on 8/8. 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 8/309:29 pm -
1 stop18h 21m
Mon 8/317:58 pm -
1 stop15h 21m
Deal found 8/8![Frontier logo]()
$304
Best flights from Seattle to St. CharlesDiscover carefully curated flight deals from Seattle to St. Charles that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated August 9, 2026.
Discover carefully curated flight deals from Seattle to St. Charles that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated August 9, 2026.
This CheapOair deal was found by Cheapflights users on 8/9. 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.
Thu 10/227:41 pm -
1 stop21h 34m
Sun 10/255:19 pm -
1 stop18h 41m
Deal found 8/9![Frontier logo]()
$298
This Southwest deal was found by Cheapflights users on 8/7. 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 11/164:40 pm -
2 stops14h 55m
Thu 11/1911:20 am -
2 stops9h 20m
Deal found 8/7![Southwest logo]()
$309
This United Airlines deal was found by Cheapflights users on 8/4. 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.
Sat 10/1011:59 pm -
1 stop8h 11m
Wed 10/145:10 am -
1 stop6h 51m
Deal found 8/4![United Airlines logo]()
$327
This Alaska Airlines deal was found by Cheapflights users on 8/9. 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 9/228:13 am -
Nonstop4h 08m
Mon 9/286:08 pm -
1 stop6h 31m
Deal found 8/9![Alaska Airlines logo]()
$337
This United Airlines deal was found by Cheapflights users on 8/5. 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 9/2111:04 pm -
2 stops10h 53m
Wed 9/231:36 pm -
2 stops11h 50m
Deal found 8/5![United Airlines logo]()
$337
This Southwest deal was found by Cheapflights users on 8/7. 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 10/2812:05 pm -
2 stops8h 00m
Thu 11/55:05 am -
2 stops10h 50m
Deal found 8/7![Southwest logo]()
$389
This Alaska Airlines deal was found by Cheapflights users on 8/7. 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.
Sun 9/136:03 pm -
Nonstop3h 56m
Fri 9/187:36 pm -
Nonstop4h 23m
Deal found 8/7![Alaska Airlines logo]()
$427
This Southwest deal was found by Cheapflights users on 8/9. 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 10/165:50 am -
2 stops8h 05m
Mon 10/195:50 pm -
2 stops8h 45m
Deal found 8/9![Southwest logo]()
$418
This Alaska Airlines deal was found by Cheapflights users on 8/6. 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 8/246:03 pm -
Nonstop3h 56m
Sat 9/56:08 pm -
1 stop6h 31m
Deal found 8/6![Alaska Airlines logo]()
$447
This Southwest deal was found by Cheapflights users on 8/5. 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 10/211:10 am -
2 stops8h 35m
Sun 10/117:00 pm -
2 stops8h 25m
Deal found 8/5![Southwest logo]()
$447
Last-minute flights from Seattle to St. CharlesDiscover last-minute flight deals from Seattle to St. Charles. Data last updated August 9, 2026 and is based on user searches.
Discover last-minute flight deals from Seattle to St. Charles. Data last updated August 9, 2026 and is based on user searches.
This Kiwi.com deal was found by Cheapflights users on 8/6. 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 8/267:06 pm -
2 stops19h 05m
Mon 8/317:58 pm -
1 stop15h 21m
Deal found 8/6![Frontier logo]()
$296
This Kiwi.com deal was found by Cheapflights users on 8/7. 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 8/277:06 pm -
2 stops20h 16m
Mon 8/317:58 pm -
1 stop15h 21m
Deal found 8/7![Frontier logo]()
$289
This Kiwi.com deal was found by Cheapflights users on 8/6. 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 8/292:37 pm -
2 stops23h 34m
Mon 8/317:58 pm -
1 stop15h 21m
Deal found 8/6![Frontier logo]()
$301
This Kiwi.com deal was found by Cheapflights users on 8/8. 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 8/309:29 pm -
1 stop18h 21m
Mon 8/317:58 pm -
1 stop15h 21m
Deal found 8/8![Frontier logo]()
$304
This Kiwi.com deal was found by Cheapflights users on 8/8. 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 9/87:06 pm -
1 stop22h 11m
Mon 9/148:10 pm -
1 stop20h 58m
Deal found 8/8![Frontier logo]()
$286
This Southwest deal was found by Cheapflights users on 8/8. 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 9/1012:50 pm -
2 stops9h 50m
Tue 9/158:25 am -
2 stops10h 25m
Deal found 8/8![Southwest logo]()
$303
This Frontier deal was found by Cheapflights users on 8/5. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/139:45 pm -
1 stop11h 32m
Fri 9/2512:17 pm -
1 stop8h 11m
Deal found 8/5![Frontier logo]()
$288
This Southwest deal was found by Cheapflights users on 8/5. 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 9/161:45 pm -
1 stop6h 55m
Wed 9/2311:55 am -
2 stops10h 25m
Deal found 8/5![Southwest logo]()
$293
This Kiwi.com deal was found by Cheapflights users on 8/5. 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 9/188:15 pm -
2 stops21h 02m
Mon 9/218:10 pm -
1 stop20h 58m
Deal found 8/5![Frontier logo]()
$306
One-way flights from Seattle to St. CharlesSearch for one-way flight options from Seattle to St. Charles. Find affordable one-way fares based on user searches. Data last updated August 9, 2026.
Search for one-way flight options from Seattle to St. Charles. Find affordable one-way fares based on user searches. Data last updated August 9, 2026.
This Southwest deal was found by Cheapflights users on 8/5. 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 11/711:45 am -
1 stop6h 15m
Deal found 8/5![Southwest logo]()
$104
This American Airlines deal was found by Cheapflights users on 8/7. 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.
Sat 10/33:41 pm -
1 stop6h 46m
Deal found 8/7![American Airlines logo]()
$108
This Delta deal was found by Cheapflights users on 8/7. 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.
Tue 10/611:10 pm -
1 stop8h 34m
Deal found 8/7![Delta logo]()
$109
This Delta deal was found by Cheapflights users on 8/7. 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 10/911:10 pm -
1 stop8h 34m
Deal found 8/7![Delta logo]()
$114
This Southwest deal was found by Cheapflights users on 8/6. 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 11/511:20 am -
2 stops11h 30m
Deal found 8/6![Southwest logo]()
$119
This Kiwi.com deal was found by Cheapflights users on 8/8. 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 9/228:15 pm -
2 stops21h 02m
Deal found 8/8![Frontier logo]()
$131
This Kiwi.com deal was found by Cheapflights users on 8/8. 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 9/118:15 pm -
2 stops37h 52m
Deal found 8/8![Frontier logo]()
$133
This Kiwi.com deal was found by Cheapflights users on 8/7. 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 10/68:15 pm -
2 stops21h 02m
Deal found 8/7![Frontier logo]()
$135
This Trip.com deal was found by Cheapflights users on 8/9. 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.
Thu 10/87:41 pm -
1 stop21h 34m
Deal found 8/9![Frontier logo]()
$136
This Kiwi.com deal was found by Cheapflights users on 8/8. 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 11/57:41 pm -
1 stop21h 34m
Deal found 8/8![Frontier logo]()
$137
This Kiwi.com deal was found by Cheapflights users on 8/7. 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 9/97:25 pm -
2 stops45h 52m
Deal found 8/7![Frontier logo]()
$138
This Super.com deal was found by Cheapflights users on 8/7. 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.
Mon 8/319:29 pm -
1 stop18h 21m
Deal found 8/7![Frontier logo]()
$147
Find flight deals from Seattle to St. Charles
Keep the following information in mind while searching for Seattle to St. Charles flight deals. Data was last updated August 9, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $286 (Kiwi.com) |
One-way from | $104 (Southwest) |
Popular in | July |
Cheapest in | January |
Average price | $463 |
Cheapflights Fare Finder
Customize your flight search to find flights from Seattle to St. Charles 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 August 9, 2026.
Use the filters below to find and compare flights from Seattle to St. Charles that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
SeattleSt. Louis
SEA Seattle/Tacoma Intl - STL Lambert-St Louis
SEASTL
Seattle/Tacoma Intl
Thu 10/22
7:41 pm-7:15 pm
1 stop21h 34m
Lambert-St Louis
Sun 10/25
5:19 pm-10:00 am
1 stop18h 41m
$298
SeattleSt. Louis
SEA Seattle/Tacoma Intl - STL Lambert-St Louis
SEASTL
Seattle/Tacoma Intl
Mon 11/16
4:40 pm-9:35 am
2 stops14h 55m
Lambert-St Louis
Thu 11/19
11:20 am-6:40 pm
2 stops9h 20m
$309
SeattleSt. Louis
SEA Seattle/Tacoma Intl - STL Lambert-St Louis
SEASTL
Seattle/Tacoma Intl
Sat 10/10
11:59 pm-10:10 am
1 stop8h 11m
Lambert-St Louis
Wed 10/14
5:10 am-10:01 am
1 stop6h 51m
$327
SeattleSt. Louis
SEA Seattle/Tacoma Intl - STL Lambert-St Louis
SEASTL
Seattle/Tacoma Intl
Tue 9/22
8:13 am-2:21 pm
Nonstop4h 08m
Lambert-St Louis
Mon 9/28
6:08 pm-10:39 pm
1 stop6h 31m
$337
SeattleSt. Louis
SEA Seattle/Tacoma Intl - STL Lambert-St Louis
SEASTL
Seattle/Tacoma Intl
Mon 9/21
11:04 pm-11:57 am
2 stops10h 53m
Lambert-St Louis
Wed 9/23
1:36 pm-11:26 pm
2 stops11h 50m
$337
SeattleSt. Louis
SEA Seattle/Tacoma Intl - STL Lambert-St Louis
SEASTL
Seattle/Tacoma Intl
Wed 10/28
12:05 pm-10:05 pm
2 stops8h 00m
Lambert-St Louis
Thu 11/5
5:05 am-1:55 pm
2 stops10h 50m
$389
SeattleSt. Louis
SEA Seattle/Tacoma Intl - STL Lambert-St Louis
SEASTL
Seattle/Tacoma Intl
Fri 10/16
5:50 am-3:55 pm
2 stops8h 05m
Lambert-St Louis
Mon 10/19
5:50 pm-12:35 am
2 stops8h 45m
$418
Quickest round-trip
SeattleSt. Louis
SEA Seattle/Tacoma Intl - STL Lambert-St Louis
SEASTL
Seattle/Tacoma Intl
Sun 9/13
6:03 pm-11:59 pm
Nonstop3h 56m
Lambert-St Louis
Fri 9/18
7:36 pm-9:59 pm
Nonstop4h 23m
$427
SeattleSt. Louis
SEA Seattle/Tacoma Intl - STL Lambert-St Louis
SEASTL
Seattle/Tacoma Intl
Mon 8/24
6:03 pm-11:59 pm
Nonstop3h 56m
Lambert-St Louis
Sat 9/5
6:08 pm-10:39 pm
1 stop6h 31m
$447
SeattleSt. Louis
SEA Seattle/Tacoma Intl - STL Lambert-St Louis
SEASTL
Seattle/Tacoma Intl
Fri 10/2
11:10 am-9:45 pm
2 stops8h 35m
Lambert-St Louis
Sun 10/11
7:00 pm-1:25 am
2 stops8h 25m
$447
Showing 1-10 of 21 resultsSorted by cheapest first
Best time to book a flight from Seattle to St. Charles
Have a flexible travel schedule? Discover the best time to fly to St. Charles from Seattle with our price prediction graph.
SEA-STL
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 Seattle to St. Charles
SEA-CH5
SEA-STL
What is the cheapest time of day to fly from SEA to CH5?
Find hourly flight availability from Seattle to St. Charles. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated August 9, 2026.
Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Seattle to St. Charles as you normally would.
Weekly flight availability from Seattle to St. Charles
Explore weekly flight availability from Seattle to St. Charles. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated August 9, 2026.
The most flights from SEA to CH5 are scheduled on a Saturday (11 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (3 on average).
How much does it cost to fly round-trip from Seattle to St. Charles?
Airfare is below average for this route at the moment.
Seattle to St. Charles flights typically cost between $361 and $614 in September.The cheapest round-trip price found within the last 5 days was $286 on Frontier (Sep 8-Sep 14).
Reviews of airlines servicing St. Charles
Get insights into the airlines that provide service to St. Charles. 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 St. Charles. Reviews last updated August 9, 2026.
Get a feel of what it's like to fly with Southwest,Alaska Airlines, andDelta from Seattle to St. Charles by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Crew
8.6
Comfort
8.0
Food
7.0
Boarding
8.1
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
8.0
ExcellentLibby,Jun 2026
TUS - LAS
Crew
8.6
Comfort
8.0
Food
7.0
Boarding
8.1
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
8.0
ExcellentLibby,Jun 2026
TUS - LAS
Crew
8.6
Comfort
8.0
Food
7.0
Boarding
8.1
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
8.0
ExcellentLibby,Jun 2026
TUS - LAS
Crew
8.6
Comfort
8.0
Food
7.0
Boarding
8.1
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
8.0
ExcellentLibby,Jun 2026
TUS - LAS
Crew
8.6
Comfort
8.0
Food
7.0
Boarding
8.1
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
8.0
ExcellentLibby,Jun 2026
TUS - LAS
Crew
8.6
Comfort
8.0
Food
7.0
Boarding
8.1
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
8.0
ExcellentLibby,Jun 2026
TUS - LAS
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Seattle and St. Charles flights
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Top 7 airlines flying from Seattle to St. Charles
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| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$104 | Average$322 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$158 | Average$301 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$181 | Average$587 | FlexibilityNo cancel fee | On-time85% | |
| Cheapest$182 | Average$382 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$207 | Average$575 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$216 | Average$431 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$226 | Average$455 | FlexibilityNo cancel fee | On-time75% |