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St. Charles

Cheap flights from Seattle (SEA) to St. Charles, MO

SEA — STL
Oct 24 — Oct 311
Sat 10/24
Sat 10/31
1 adult, Economy
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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 Thursday or Tuesday and return on a Friday

Find flight deals from Seattle to St. Charles

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Popular in

December

Cheapest in

January

Average price

$427
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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High demand for flights, 7% potential price rise
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Cheapest flight prices on average. 2% potential price decrease ($13 potential savings vs. average RT price).
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Average for round-trip flights in September 2026
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Cheapflights Insights

Everything you need to know about your flight from Seattle to St. Charles

What is the cheapest time of day to fly from SEA to CH5?

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.

Reviews of airlines servicing St. Charles

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.
Southwest
8.0
Very good
4,199 reviews

Overall

8.0

Boarding

8.1

Comfort

8.0

Crew

8.6

Entertainment

7.5

Food

7.0

Reviews

1 / 20
4.0
Okay

Steven,Sep 2026

OGG - HNL

It was a red eye overnight which I prefer. But this time the seat was SOOOO uncomfortable that sleeping was difficult and painful
Southwest
8.0
Very good
4,199 reviews
Southwest
8.0
Very good
4,199 reviews

Overall

8.0

Boarding

8.1

Comfort

8.0

Crew

8.6

Entertainment

7.5

Food

7.0

Reviews

1 / 20
4.0
Okay

Steven,Sep 2026

OGG - HNL

It was a red eye overnight which I prefer. But this time the seat was SOOOO uncomfortable that sleeping was difficult and painful
Alaska Airlines
7.9
Good
12,963 reviews
Southwest
8.0
Very good
4,199 reviews

Overall

8.0

Boarding

8.1

Comfort

8.0

Crew

8.6

Entertainment

7.5

Food

7.0

Reviews

1 / 20
4.0
Okay

Steven,Sep 2026

OGG - HNL

It was a red eye overnight which I prefer. But this time the seat was SOOOO uncomfortable that sleeping was difficult and painful
Delta
7.8
Good
8,593 reviews
Southwest
8.0
Very good
4,199 reviews

Overall

8.0

Boarding

8.1

Comfort

8.0

Crew

8.6

Entertainment

7.5

Food

7.0

Reviews

1 / 20
4.0
Okay

Steven,Sep 2026

OGG - HNL

It was a red eye overnight which I prefer. But this time the seat was SOOOO uncomfortable that sleeping was difficult and painful
United Airlines
7.4
Good
10,233 reviews
Southwest
8.0
Very good
4,199 reviews

Overall

8.0

Boarding

8.1

Comfort

8.0

Crew

8.6

Entertainment

7.5

Food

7.0

Reviews

1 / 20
4.0
Okay

Steven,Sep 2026

OGG - HNL

It was a red eye overnight which I prefer. But this time the seat was SOOOO uncomfortable that sleeping was difficult and painful
American Airlines
7.0
Good
12,073 reviews
Southwest
8.0
Very good
4,199 reviews

Overall

8.0

Boarding

8.1

Comfort

8.0

Crew

8.6

Entertainment

7.5

Food

7.0

Reviews

1 / 20
4.0
Okay

Steven,Sep 2026

OGG - HNL

It was a red eye overnight which I prefer. But this time the seat was SOOOO uncomfortable that sleeping was difficult and painful

Related info for your journey

  • 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 2 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 1 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 United Airlines, which is currently one of the cheapest options available, starting at $74. Southwest flights start at $79 while deals on American Airlines start at $88 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 Qatar Airways (94%), Alaska Airlines (84%) and American Airlines (83%).

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

    On average you can expect to pay $436 for a flight from Seattle to St. Charles. The cheapest flight overall is $214 while the most popular route, (Seattle/Tacoma Intl - Lambert-St Louis) is currently priced at $208.

  • 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.

See more FAQs

Browse thousands of different options on Cheapflights for your next trip

Top 6 airlines flying from Seattle to St. Charles

AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$124Average$333FlexibilityNo cancel feeOn-timeN/A
FrontierCheapest$158Average$301FlexibilityNo cancel feeOn-time62%
SouthwestCheapest$182Average$380FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$182Average$534FlexibilityNo cancel feeOn-time71%
Alaska AirlinesCheapest$226Average$467FlexibilityNo cancel feeOn-time75%
United AirlinesCheapest$248Average$394FlexibilityNo cancel feeOn-time69%

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