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$80+ Cheap flights from Seattle to St. Louis (SEA - STL)

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 10/22. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — STL
ago. 19 — ago. 261
mar. 8/19
mar. 8/26
1 adult, Economy
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Cheapflights Tip: The best prices from Seattle/Tacoma Intl to Lambert-St Louis are usually found in September or October, booked 57 days in advance, depart on a Thursday or Friday and return on a Tuesday

Cheap flight deals from Seattle to St. Louis

Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) to St. Louis (STL). 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 agosto 14, 2025.

Round-trip from

$169
(FlightHub)

One-way from

$80
(Priceline)

Popular in

December

Cheapest in

September

Average price

$392

Good round-trip deal

$249 or less

Good one-way deal

$233 or less
From Seattle/Tacoma Intl to Lambert-St Louis
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One-way flight from Seattle/Tacoma Intl to Lambert-St Louis
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Highest demand for flights based on searches. 6% potential increase in price ($27 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($9 potential savings vs. average RT price).
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Average for round-trip flights in August 2025
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Price to beat on a round-trip flight from Seattle/Tacoma Intl to Lambert-St Louis.
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Price to beat on a one-way flight from Seattle/Tacoma Intl to Lambert-St Louis.
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Find flight deals from Seattle to St. Louis

Cheapest flights from Seattle to St. Louis
Explore the most affordable flight options available from Seattle to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on agosto 14, 2025.

This FlightHub deal was found by Cheapflights users on 8/14. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 9/36:41 amSEA - STL
1 stop24h 25mFrontier
jue. 9/47:55 pmSTL - SEA
1 stop6h 35mFrontier
Deal found 8/14$169
This FlightHub deal was found by Cheapflights users on 8/14. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mar. 9/167:00 amSEA - STL
1 stop24h 06mFrontier
dom. 9/217:55 pmSTL - SEA
1 stop6h 35mFrontier
Deal found 8/14$172
This Booking.com deal was found by Cheapflights users on 8/14. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 9/116:12 amSEA - STL
1 stop24h 54mFrontier
lun. 9/157:55 pmSTL - SEA
1 stop6h 35mFrontier
Deal found 8/14$174
This FlightHub deal was found by Cheapflights users on 8/14. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 9/36:41 amSEA - STL
1 stop24h 25mFrontier
mar. 9/167:55 pmSTL - SEA
1 stop29h 04mFrontier
Deal found 8/14$175
This Delta deal was found by Cheapflights users on 8/14. 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.
mié. 9/36:10 amSEA - STL
1 stop8h 35mDelta
mié. 9/102:25 pmSTL - SEA
1 stop6h 35mDelta
Deal found 8/14$177
This Delta deal was found by Cheapflights users on 8/12. 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.
mar. 9/96:10 amSEA - STL
1 stop6h 14mDelta
vie. 9/127:00 pmSTL - SEA
1 stop6h 59mDelta
Deal found 8/12$183
This American Airlines deal was found by Cheapflights users on 8/12. 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.
jue. 9/251:02 pmSEA - STL
1 stop8h 46mAmerican Airlines
lun. 10/64:34 pmSTL - SEA
1 stop9h 58mAmerican Airlines
Deal found 8/12$189
This United Airlines deal was found by Cheapflights users on 8/12. 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.
sáb. 9/1311:58 pmSEA - STL
1 stop7h 59mUnited Airlines
mar. 9/165:49 pmSTL - SEA
1 stop7h 10mUnited Airlines
Deal found 8/12$192
This United Airlines deal was found by Cheapflights users on 8/13. 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.
jue. 9/47:00 amSEA - STL
1 stop6h 44mUnited Airlines
mié. 9/104:40 pmSTL - SEA
1 stop6h 42mUnited Airlines
Deal found 8/13$198
This FlightHub deal was found by Cheapflights users on 8/14. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
vie. 10/102:31 pmSEA - STL
1 stop16h 36mFrontier
dom. 10/1910:17 amSTL - SEA
1 stop24h 31mFrontier
Deal found 8/14$200
This Booking.com deal was found by Cheapflights users on 8/14. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sáb. 11/86:00 amSEA - STL
2 stops25h 17mFrontier
mar. 11/117:52 pmSTL - SEA
1 stop29h 10mFrontier
Deal found 8/14$201
This American Airlines deal was found by Cheapflights users on 8/13. 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.
vie. 9/512:19 pmSEA - STL
1 stop8h 48mAmerican Airlines
sáb. 9/66:20 amSTL - SEA
1 stop10h 29mAmerican Airlines
Deal found 8/13$203

Cheapflights Fare Finder

 
Customize your flight search to find flights from Seattle to St. Louis 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 agosto 14, 2025.
Use the filters below to find and compare flights from Seattle to St. Louis that are best for you.

Fly from

Seattle

Fly to

St. Louis

Route

Depart

Return

Price

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

mié. 9/3

6:41 am-9:06 am

1 stop24h 25m

Lambert-St Louis

jue. 9/4

7:55 pm-12:30 am

1 stop6h 35m

$169

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

vie. 10/24

6:39 pm-3:56 pm

1 stop19h 17m

Lambert-St Louis

dom. 10/26

7:52 pm-7:33 am

1 stop13h 41m

$169

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

mar. 9/16

7:00 am-9:06 am

1 stop24h 06m

Lambert-St Louis

dom. 9/21

7:55 pm-12:30 am

1 stop6h 35m

$172

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

vie. 9/12

6:12 am-9:06 am

1 stop24h 54m

Lambert-St Louis

lun. 9/15

7:55 pm-12:30 am

1 stop6h 35m

$174

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

jue. 9/11

6:12 am-9:06 am

1 stop24h 54m

Lambert-St Louis

lun. 9/15

7:55 pm-12:30 am

1 stop6h 35m

$174

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

mié. 9/3

6:41 am-9:06 am

1 stop24h 25m

Lambert-St Louis

mar. 9/16

7:55 pm-10:59 pm

1 stop29h 04m

$175

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

sáb. 11/8

6:00 am-9:07 am

1 stop25h 07m

Lambert-St Louis

mar. 11/11

7:52 pm-11:02 pm

1 stop29h 10m

$175

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

vie. 9/12

6:12 am-9:06 am

1 stop24h 54m

Lambert-St Louis

mar. 9/16

7:55 pm-10:59 pm

1 stop29h 04m

$175

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

mar. 9/9

11:55 pm-8:36 am

1 stop6h 41m

Lambert-St Louis

mar. 9/16

7:40 am-2:39 pm

1 stop8h 59m

$177

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

mié. 9/3

5:30 am-1:30 pm

1 stop6h 00m

Lambert-St Louis

mié. 9/10

7:35 am-2:43 pm

1 stop9h 08m

$177

Flights are sorted by cheapest round-trip flights first.

Deals found on 8/14

Showing 1-10 of 19 results
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The best insider tips for Seattle to St. Louis flights

Snippets provided in this section are AI-generated based on a summarization of Cheapflights-commissioned articles. The articles are presented as-is, for general informational purposes only, and may not be up-to-date. The opinions contained in the articles are original to the author and reflect their authentic experience, which may vary significantly from the experience of others.
Cheapflights partnered with top experts to bring you the best recommendations for your Seattle to St. Louis trip
Airports
SEA

Plan to arrive at SEA two hours before your flight. Use SEA Spot Saver for security appointments to reduce wait times.

Read more about SEAby Brandon Schultz
STL

Use the MetroLink light rail from STL for a convenient and economical way to reach downtown St. Louis in about 40 minutes.

Read more about STLby Taryn White
Our travel experts
Taryn White

Taryn White

Expert on STL

Taryn White

Taryn White

Taryn White is a freelance travel writer, digital creator, and travel advisor who has visited nearly 100 countries and all 50 states. She’s familiar with many airports and enjoys beach hopping, boutique hotels, spa experiences, and exploring local culture. Her work has appeared in Travel + Leisure, Condé Nast Traveler, National Geographic, Smithsonian Magazine, AFAR, and more.

Read more
Brandon Schultz

Brandon Schultz

Expert on SEA

Brandon Schultz

Brandon Schultz

Brandon Schultz is an award-winning food and travel writer based in New York City. His work has appeared in Forbes, AAA, Thrillist, Travel + Leisure, and The Daily Meal, among many others, and he is the author of 6 books, including 3 cookbooks.

Read more

Best time to book a flight from Seattle to St. Louis

Have a flexible travel schedule? Discover the best time to fly to St. Louis 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.

Cheapflights Insights

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

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

Use this chart to determine the optimal time to book a round-trip flight from Seattle to St. Louis. Price data was last updated on August 8, 2025.

The best time to book flights from Seattle to St. Louis is 57 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. Louis?

Currently, August is the cheapest month in which you can book a flight from Seattle to St. Louis (average of $311). Flying from Seattle to St. Louis 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 STL?

Find hourly flight availability from Seattle to St. Louis. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated agosto 14, 2025.

When flying from Seattle to St. Louis, the time of day you fly usually plays a role in the price. Save by searching for a flight in the evening, which can drop the price by up to 39% versus a flight in the morning.

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

Use this chart to determine the cheapest time to fly round-trip from Seattle to St. Louis. Price data was last updated on August 10, 2025.

Travelers seeking maximum savings on their Seattle to St. Louis 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.

Weekly flight availability from Seattle to St. Louis

Explore weekly flight availability from Seattle to St. Louis. 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 agosto 14, 2025.

The most flights from SEA to STL are scheduled on a Thursday (17 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (8 on average).

Reviews of airlines servicing St. Louis

Get insights into the airlines that provide service to St. Louis. 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. Louis. Reviews last updated agosto 14, 2025.
Peruse reviews from past customers who have flown with Alaska Airlines, Southwest, and Delta from Seattle to St. Louis to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
10,000 reviews

Crew

8.5

Boarding

8.1

Food

7.1

Overall

8.0

Entertainment

7.0

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Alaska Airlines
8.0
Very good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Crew

8.5

Boarding

8.1

Food

7.1

Overall

8.0

Entertainment

7.0

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Southwest
8.0
Very good
4,244 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Crew

8.5

Boarding

8.1

Food

7.1

Overall

8.0

Entertainment

7.0

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Delta
8.0
Very good
7,980 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Crew

8.5

Boarding

8.1

Food

7.1

Overall

8.0

Entertainment

7.0

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Hawaiian Airlines
7.8
Good
2,656 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Crew

8.5

Boarding

8.1

Food

7.1

Overall

8.0

Entertainment

7.0

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
American Airlines
7.2
Good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Crew

8.5

Boarding

8.1

Food

7.1

Overall

8.0

Entertainment

7.0

Comfort

7.8

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.

Related info for your journey

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

  • What airports do I use to fly from Seattle to St. Louis?

    If you book a flight from Seattle to St. Louis, you will be flying from Seattle/Tacoma Intl to Lambert-St Louis. Flights to Lambert-St Louis (STL) from Seattle/Tacoma Intl (SEA) take 3h 52m for a nonstop flight. There are 12 flights from Seattle/Tacoma Intl to St. Louis per day from 7 airlines.

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

    The Seattle/Tacoma Intl to Lambert-St Louis flight path was viewed by 4 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 flying from Seattle to St. Louis round-trip?

    Cheapflights users have booked flights from Seattle to St. Louis round-trip from $134. Other airlines that can offer you cheap pricing are Delta, from $178, and American Airlines, from $186. These flights start at 65% lower than the current average price 3 months from now.

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

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Seattle to St. Louis on time: Qatar Airways (72%), Alaska Airlines (70%), Air Tahiti Nui (67%).

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

    The cheapest flight price from Seattle to St. Louis is $126. On average you can expect to pay $568. The most popular route, (Seattle/Tacoma Intl - Lambert-St Louis), can usually be booked for $177.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Seattle to St. Louis 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. Louis?

    Currently, August is the cheapest month in which you can book a flight from Seattle to St. Louis (average of $311). Flying from Seattle to St. Louis 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.

See more FAQs

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
O'Fallon
Fairview Heights
Maryland Heights
Collinsville
Eureka
St. Peters
Glencoe
Alton
Chesterfield
Farmington
Festus

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Alternative routes for Seattle to St. Louis

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Top 7 airlines flying from Seattle to St. Louis

Discover the top 7 airlines that operate flights from Seattle to St. Louis. 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 agosto 14, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$134Average$271FlexibilityNo cancel feeOn-time62%
DeltaCheapest$178Average$301FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$186Average$451FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$188Average$433FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$216Average$376FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$236Average$417FlexibilityNo cancel feeOn-time75%
Hawaiian AirlinesCheapest$237Average$386FlexibilityNo cancel feeOn-time85%

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