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St. Charles

$81+ 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 4/22. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — STL
Mar 9 — Mar 161
Sun 3/9
Sun 3/16
1 adult, Economy
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The best prices from Seattle/Tacoma Intl to St. Charles are usually found in September or April, booked 73 days in advance, depart on a Thursday or Wednesday and return on a Wednesday

Cheap 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 March 4, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$237
(Hawaiian Airlines)

One-way from

$81
(CheapOair)

Popular in

December

Cheapest in

September

Average price

$339
Provider with most accurate pricing for Seattle/Tacoma Intl-Lambert-St Louis flight deals.
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Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-Lambert-St Louis flights.
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From Seattle/Tacoma Intl to St. Charles
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One-way flight from Seattle/Tacoma Intl to St. Charles
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Highest demand for flights based on searches. 7% potential increase in price ($32 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($8 potential savings vs. average RT price).
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Average for round-trip flights in March 2025
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Find flight deals from Seattle to St. Charles

Cheapest flights from Seattle to St. Charles
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 March 4, 2025.

This Hawaiian Airlines deal was found by Cheapflights users on 3/3. 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 Hawaiian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/16:04 pmSEA - STL
Nonstop3h 55mHawaiian Airlines
Wed 4/163:11 pmSTL - SEA
Nonstop4h 34mHawaiian Airlines
Deal found 3/3$237
This CheapOair deal was found by Cheapflights users on 3/3. 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 5/226:00 amSEA - STL
1 stop25h 12mFrontier
Thu 5/299:49 pmSTL - SEA
1 stop24h 03mFrontier
Deal found 3/3$244
This Delta deal was found by Cheapflights users on 3/3. 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 5/107:25 amSEA - STL
2 stops12h 08mDelta
Mon 7/286:59 pmSTL - SEA
1 stop6h 59mDelta
Deal found 3/3$262
This Alaska Airlines deal was found by Cheapflights users on 3/3. 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.
Wed 5/76:03 pmSEA - STL
Nonstop3h 56mAlaska Airlines
Sat 8/27:32 pmSTL - SEA
Nonstop4h 28mAlaska Airlines
Deal found 3/3$263
This Southwest deal was found by Cheapflights users on 3/3. 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 5/15:35 amSEA - STL
2 stops8h 15mSouthwest
Tue 5/66:05 pmSTL - SEA
1 stop6h 55mSouthwest
Deal found 3/3$275
This Expedia deal was found by Cheapflights users on 3/2. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/311:59 pmSEA - STL
1 stop9h 35mMultiple Airlines
Tue 4/86:44 amSTL - SEA
Nonstop4h 30mMultiple Airlines
Deal found 3/2$298
This American Airlines deal was found by Cheapflights users on 3/3. 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.
Wed 4/912:59 amSEA - STL
1 stop7h 34mAmerican Airlines
Mon 4/146:00 pmSTL - SEA
1 stop7h 09mAmerican Airlines
Deal found 3/3$307
This United Airlines deal was found by Cheapflights users on 3/3. 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 3/3111:59 pmSEA - STL
1 stop7h 57mUnited Airlines
Tue 4/81:43 pmSTL - SEA
2 stops13h 15mUnited Airlines
Deal found 3/3$311
This Mytrip deal was found by Cheapflights users on 3/2. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/94:58 pmSEA - STL
2 stops23h 34mSpirit Airlines
Sun 5/117:37 pmSTL - SEA
2 stops19h 05mSpirit Airlines
Deal found 3/2$366

Find flights from Seattle to St. Charles within your budget

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 March 4, 2025.

Fly from

Seattle

Fly to

St. Charles

Route

Depart

Return

Price

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Tue 4/1

6:04 pm-11:59 pm

Nonstop3h 55m

Lambert-St Louis

Wed 4/16

3:11 pm-5:45 pm

Nonstop4h 34m

$237

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Thu 5/22

6:00 am-9:12 am

1 stop25h 12m

Lambert-St Louis

Thu 5/29

9:49 pm-7:52 pm

1 stop24h 03m

$244

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Sun 5/11

5:30 am-1:34 pm

1 stop6h 04m

Lambert-St Louis

Wed 7/30

6:59 pm-11:58 pm

1 stop6h 59m

$254

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Wed 5/7

6:03 pm-11:59 pm

Nonstop3h 56m

Lambert-St Louis

Tue 7/29

7:32 pm-10:00 pm

Nonstop4h 28m

$263

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Thu 5/1

5:35 am-3:50 pm

2 stops8h 15m

Lambert-St Louis

Tue 5/6

6:05 pm-11:00 pm

1 stop6h 55m

$275

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Thu 4/3

11:59 pm-11:34 am

1 stop9h 35m

Lambert-St Louis

Tue 4/8

6:44 am-9:14 am

Nonstop4h 30m

$298

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Wed 4/9

12:59 am-10:33 am

1 stop7h 34m

Lambert-St Louis

Mon 4/14

6:00 pm-11:09 pm

1 stop7h 09m

$307

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Mon 3/31

11:59 pm-9:56 am

1 stop7h 57m

Lambert-St Louis

Tue 4/8

1:43 pm-12:58 am

2 stops13h 15m

$311

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Fri 5/9

4:58 pm-6:32 pm

2 stops23h 34m

Lambert-St Louis

Sun 5/11

7:37 pm-12:42 pm

2 stops19h 05m

$366

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Tue 4/22

6:00 am-10:01 am

1 stop26h 01m

$81

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/4

Showing 1-10 of 18 results
1
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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.
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.

Travel insights for flights from Seattle to St. Charles

Get recent, data-driven insights about flights from Seattle to St. Charles including ideal travel times, pricing trends, and more.

How far ahead should I book a flight from Seattle to St. Charles?

Use this chart to determine the optimal time to book a round-trip flight from Seattle to St. Charles. Price data was last updated on February 28, 2025.

The best time to book flights from Seattle to St. Charles is 73 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 Seattle to St. Charles?

Currently, August is the cheapest month in which you can book a flight from Seattle to St. Charles (average of $311). Flying from Seattle to St. Charles in March is currently the most expensive (average of $356). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from SEA to 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 March 4, 2025.

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.

What is the cheapest day to fly from Seattle to St. Charles?

Use this chart to determine the cheapest time to fly round-trip from Seattle to St. Charles. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Seattle to St. Charles flight should consider departing on Tuesday evenings when fares are most often at their lowest. Monday at noon flights should be avoided if possible as fares are typically the most expensive at this time.

Rainfall in St. Charles by month

Plan your trip to St. Charles by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in St. Charles ranges from 2.2 - 4.7 inches per month. May is typically the wettest month, when rainfall can reach 4.7 in. February is typically the driest time to visit St. Charles when rainfall is around 2.2 in.

Temperature in St. Charles by month

Plan your trip to St. Charles by taking into account the average temperature totals by month.

If weather is an important factor for your trip to St. Charles, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 80.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 32.0 F).

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 March 4, 2025.
Read through reviews of airlines operating flights from Seattle to St. Charles, such as Southwest, Alaska Airlines and Delta. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.1
Very good
4,331 reviews

Overall

8.1

Comfort

8.1

Crew

8.7

Food

7.1

Entertainment

7.6

Boarding

8.2

Reviews

1 / 20

8.0
Excellent

Ila,Mar 2025

HOU - DAL

Our original flight was delayed. We were able to change our flight and got home at close to the same time. Looking forward to when you have assigned seating.

Southwest
8.1
Very good
4,331 reviews
Southwest
8.1
Very good
4,331 reviews

Overall

8.1

Comfort

8.1

Crew

8.7

Food

7.1

Entertainment

7.6

Boarding

8.2

Reviews

1 / 20

8.0
Excellent

Ila,Mar 2025

HOU - DAL

Our original flight was delayed. We were able to change our flight and got home at close to the same time. Looking forward to when you have assigned seating.

Alaska Airlines
8.0
Very good
9,713 reviews
Southwest
8.1
Very good
4,331 reviews

Overall

8.1

Comfort

8.1

Crew

8.7

Food

7.1

Entertainment

7.6

Boarding

8.2

Reviews

1 / 20

8.0
Excellent

Ila,Mar 2025

HOU - DAL

Our original flight was delayed. We were able to change our flight and got home at close to the same time. Looking forward to when you have assigned seating.

Delta
8.0
Very good
8,061 reviews
Southwest
8.1
Very good
4,331 reviews

Overall

8.1

Comfort

8.1

Crew

8.7

Food

7.1

Entertainment

7.6

Boarding

8.2

Reviews

1 / 20

8.0
Excellent

Ila,Mar 2025

HOU - DAL

Our original flight was delayed. We were able to change our flight and got home at close to the same time. Looking forward to when you have assigned seating.

Hawaiian Airlines
7.9
Good
2,319 reviews
Southwest
8.1
Very good
4,331 reviews

Overall

8.1

Comfort

8.1

Crew

8.7

Food

7.1

Entertainment

7.6

Boarding

8.2

Reviews

1 / 20

8.0
Excellent

Ila,Mar 2025

HOU - DAL

Our original flight was delayed. We were able to change our flight and got home at close to the same time. Looking forward to when you have assigned seating.

United Airlines
7.4
Good
8,678 reviews
Southwest
8.1
Very good
4,331 reviews

Overall

8.1

Comfort

8.1

Crew

8.7

Food

7.1

Entertainment

7.6

Boarding

8.2

Reviews

1 / 20

8.0
Excellent

Ila,Mar 2025

HOU - DAL

Our original flight was delayed. We were able to change our flight and got home at close to the same time. Looking forward to when you have assigned seating.

Related info for your journey

Find useful and relevant information for your journey from Seattle to St. Charles. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly from for flights from Seattle to St. Charles?

    If you book a flight to St. Charles from Seattle, you will be flying from Seattle/Tacoma Intl, which is the city’s only airport. Seattle/Tacoma Intl (SEA) is located 11.4 mi from the center of Seattle. There are 3 flights from Seattle/Tacoma Intl to St. Charles per day from 6 different airlines.

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

    This flight path from Seattle/Tacoma Intl to St. Charles was viewed by 5 users in the past month. Keep an eye out for changes in search interest prior to high and low season.

  • What are the cheapest airlines to fly from Seattle to St. Charles one-way?

    To fly one-way, consider booking your trip with Frontier, which is currently one of the cheapest options available, starting at $81. Delta flights start at $95 while deals on Southwest start at $100 one-way.

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

    The top 3 most reliable airlines when flying from Seattle to St. Charles are Hawaiian Airlines (97%), Alaska Airlines (96%) and Air Tahiti Nui (96%).

  • What are the cheapest flights from Seattle to St. Charles?

    On average you can expect to pay $596 for a flight from Seattle to St. Charles. The cheapest flight overall is $108 while the most popular route, (Seattle/Tacoma Intl - Lambert-St Louis) is currently priced at $189.

  • Can I find deals for flights from Seattle to St. Charles that include hotel bookings?

    Yes. In addition to deals on Seattle to St. Charles flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Seattle to St. Charles?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Seattle to St. Charles.

  • Can I find deals for business class flights from Seattle to St. Charles?

    Yes. Cheapflights offers flight deals from Seattle to St. Charles by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Seattle to St. Charles?

    Currently, August is the cheapest month in which you can book a flight from Seattle to St. Charles (average of $311). Flying from Seattle to St. Charles in March is currently the most expensive (average of $356). 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.

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Top 6 airlines flying from Seattle to St. Charles

Discover the top 6 airlines that operate flights from Seattle to St. Charles. 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 March 4, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$141Average$246FlexibilityNo cancel feeOn-time62%
DeltaCheapest$196Average$303FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$196Average$560FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$216Average$355FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$236Average$419FlexibilityNo cancel feeOn-time75%
SouthwestCheapest$276Average$528FlexibilityNo cancel feeOn-time63%
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