$69 Cheap Flights from Seattle (SEA) to St. Louis (STL)

View $69 flight on Sat, Dec 6, 2025Opens in a new window

Popular airlines from Seattle-Tacoma International Airport (SEA) to St. Louis Lambert Intl. Airport (STL)

Cheap Flights from Seattle to St. Louis (SEA-STL)

Prices were available within the past 7 days and start at $69 for one-way flights and $138 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

United
Wed, Oct 29 - Sat, Nov 1
SEA
Seattle
STL
St. Louis
$138 Roundtrip, found 5 hours ago
$138
Roundtrip
found 5 hours ago
Select United flight, departing Wed, Oct 29 from Seattle to St. Louis, returning Sat, Nov 1, priced at $138 found 5 hours ago
Southwest Airlines
Wed, Oct 29 - Sat, Nov 1
SEA
Seattle
STL
St. Louis
$142 Roundtrip, found 5 hours ago
$142
Roundtrip
found 5 hours ago
Select Southwest Airlines flight, departing Wed, Oct 29 from Seattle to St. Louis, returning Sat, Nov 1, priced at $142 found 5 hours ago
Southwest Airlines
Sat, Dec 6 - Tue, Dec 9
SEA
Seattle
STL
St. Louis
$147 Roundtrip, found 1 hour ago
$147
Roundtrip
found 1 hour ago
Select Southwest Airlines flight, departing Sat, Dec 6 from Seattle to St. Louis, returning Tue, Dec 9, priced at $147 found 1 hour ago
Southwest Airlines
Wed, Oct 29 - Sat, Nov 1
SEA
Seattle
STL
St. Louis
$148 Roundtrip, found 5 hours ago
$148
Roundtrip
found 5 hours ago
Select Southwest Airlines flight, departing Wed, Oct 29 from Seattle to St. Louis, returning Sat, Nov 1, priced at $148 found 5 hours ago
Southwest Airlines
Tue, Jan 6 - Sat, Jan 10
SEA
Seattle
STL
St. Louis
$152 Roundtrip, found 3 hours ago
$152
Roundtrip
found 3 hours ago
Select Southwest Airlines flight, departing Tue, Jan 6 from Seattle to St. Louis, returning Sat, Jan 10, priced at $152 found 3 hours ago
United
Tue, Nov 4 - Mon, Nov 10
SEA
Seattle
STL
St. Louis
$154 Roundtrip, found 5 hours ago
$154
Roundtrip
found 5 hours ago
Select United flight, departing Tue, Nov 4 from Seattle to St. Louis, returning Mon, Nov 10, priced at $154 found 5 hours ago
Southwest Airlines
Mon, Nov 10 - Wed, Nov 12
SEA
Seattle
STL
St. Louis
$157 Roundtrip, just found
$157
Roundtrip
just found
Select Southwest Airlines flight, departing Mon, Nov 10 from Seattle to St. Louis, returning Wed, Nov 12, priced at $157 just found
American Airlines
Sat, Dec 6 - Tue, Dec 9
SEA
Seattle
STL
St. Louis
$159 Roundtrip, found 1 hour ago
$159
Roundtrip
found 1 hour ago
Select American Airlines flight, departing Sat, Dec 6 from Seattle to St. Louis, returning Tue, Dec 9, priced at $159 found 1 hour ago
Delta
Mon, Nov 10 - Wed, Nov 12
SEA
Seattle
STL
St. Louis
$162 Roundtrip, just found
$162
Roundtrip
just found
Select Delta flight, departing Mon, Nov 10 from Seattle to St. Louis, returning Wed, Nov 12, priced at $162 just found
Alaska Airlines
Mon, Mar 2 - Wed, Mar 4
SEA
Seattle
STL
St. Louis
$179 Roundtrip, found 14 hours ago
$179
Roundtrip
found 14 hours ago
Select Alaska Airlines flight, departing Mon, Mar 2 from Seattle to St. Louis, returning Wed, Mar 4, priced at $179 found 14 hours ago

Find the cheapest month to fly from Seattle (SEA) to St. Louis (STL)

November is typically the cheapest month to fly

From $140 - $368 per traveler.

Alternative airports near St. Louis

Prices were available within the past 7 days. Prices and availability are subject to change.

Select flight to Lambert-St. Louis Intl. STL. Cheapest option available. Average driving time to city center is 20 minutes. Flights from $287
STL
Lambert-St. Louis Intl.
Cheapest
Average driving time to city center20 min
Flights from $287

Frequently asked questions

How much does a flight from Seattle - Tacoma Intl. Airport (SEA) to Lambert-St. Louis Intl. Airport (STL) cost?
Snag a cheap one-way flight from $69 or cheap return flight from $138 from Seattle - Tacoma Intl. Airport (SEA) to Lambert-St. Louis Intl. Airport (STL) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to find our cheapest flight offers on this route.
What is the cheapest month to fly from Seattle - Tacoma Intl. Airport (SEA) to Lambert-St. Louis Intl. Airport (STL)?
October is the least expensive month to fly from SEA to STL. Timing your trip outside of the busy season is often the key to finding better fares.
Which airlines fly direct from Seattle - Tacoma Intl. Airport (SEA) to Lambert-St. Louis Intl. Airport (STL)?
Hop on a nonstop flight with Alaska Airlines and head straight from Seattle - Tacoma Intl. Airport (SEA) to Lambert-St. Louis Intl. Airport (STL).
What is the cheapest airline that flies from Seattle - Tacoma Intl. Airport (SEA) to Lambert-St. Louis Intl. Airport (STL)?
Expedia's filter tool lets you easily compare airlines, flight times and baggage options all in one place. Select your preferences, then sort by "Price (lowest to highest)" to see which carrier offers the cheapest SEA to STL flight.
How many flights per day from Seattle - Tacoma Intl. Airport (SEA) to Lambert-St. Louis Intl. Airport (STL)?
On average, just 1 nonstop flight departs each day from Seattle - Tacoma Intl. Airport (SEA) to Lambert-St. Louis Intl. Airport (STL). Looking for more options? Use our filter tool to find flights with layovers and squeeze in a visit to another city along the way.
What are the most popular departure times for flights from Seattle - Tacoma Intl. Airport (SEA) to Lambert-St. Louis Intl. Airport (STL)?
More people fly between SEA and STL at 8 AM than at any other point in the day. Prefer a quieter experience? Travel outside of rush hours and it's possible you'll save on your fare as well.
What day of the week has the most flights from SEA to STL?
If you depart on a Friday, you'll get the largest range of choices for flights from Seattle - Tacoma Intl. Airport (SEA) to Lambert-St. Louis Intl. Airport (STL).
What is the earliest flight from Seattle - Tacoma Intl. Airport (SEA) to Lambert-St. Louis Intl. Airport (STL)?
Seattle - Tacoma Intl. Airport (SEA)'s earliest flight to Lambert-St. Louis Intl. Airport (STL) takes off at approximately 8:00AM UTC-8. With a flight time of 3h 53m, you'll touch down at around 1:53PM UTC-6.
How long does it take to fly from Seattle - Tacoma Intl. Airport (SEA) to Lambert-St. Louis Intl. Airport (STL)?
The average flight time from SEA to STL is 3 hours and 52 minutes, covering a total distance of 1,700 mi.
What airline has the least delays from SEA to STL?
American Airlines has the best performance for on-time direct flights from Seattle - Tacoma Intl. Airport (SEA) to Lambert-St. Louis Intl. Airport (STL), with an on-time rating of 98%. Use the Expedia App to look up your flight status before you jet off and receive notifications about any changes.
What is the best time to fly from Seattle - Tacoma Intl. Airport (SEA) to Lambert-St. Louis Intl. Airport (STL)?
To land at Lambert-St. Louis Intl. Airport (STL) on schedule, pick a flight that leaves Seattle - Tacoma Intl. Airport (SEA) before 3 PM. The likelihood of cancellations is 22% higher, on average, for departures after this time.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
What airports do you fly into for St. Louis from Seattle - Tacoma Intl. Airport (SEA)?
If you're traveling on a direct flight from Seattle - Tacoma Intl. Airport (SEA) to St. Louis, Lambert-St. Louis Intl. Airport (STL) is the only airport you can touch down at.
Is it cheaper to buy a plane ticket from Seattle - Tacoma Intl. Airport (SEA) to Lambert-St. Louis Intl. Airport (STL) last-minute?
Last-minute fares from SEA to STL are generally more expensive. To secure the lowest prices, start looking for flights well ahead of time. That said, if you can play around with your travel dates, you may land a cheap fare right before your journey.
Is it cheaper to book a SEA to STL flight and hotel package?
You can save money by booking a SEA to STL flight and hotel package compared to booking separately. In fact, you could save hundreds of dollars by bundling with Expedia. And it's simple to manage it all in one place. After selecting your ideal accommodations and flights, consider other add-ons like car rentals, tours and activities.
Can I cancel or change the date of my flight from Seattle - Tacoma Intl. Airport (SEA) to Lambert-St. Louis Intl. Airport (STL)?
In most instances, you can cancel or modify your SEA to STL flight. However, there may be additional fees, especially if you made your booking over 24 hours ago. Double-check your itinerary for the airline's rules and fees on flight changes, or if you'd like more information, visit our Customer Service portal.

Travel information

Travel information

Origin airport
Seattle - Tacoma Intl.
Destination airport
Lambert-St. Louis Intl.
Airlines serving
Alaska Airlines, American Airlines, Delta, Frontier Airlines, Southwest Airlines, United
Roundtrip price
$137
Distance
1705 mi
Average flight time
6 hours 55 mins

Book with confidence

Book with confidence

Seattle to St. Louis Flights

The cheapest times to fly from Seattle to St. Louis

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Seattle to St. Louis are during the month of October. You can find some of the cheapest flights from Seattle to St. Louis with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Seattle to St. Louis

Sunday is one of the best days to book for cheap flights from Seattle to St. Louis: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Seattle to St. Louis

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Seattle to St. Louis in 2025. You can also book with separate airlines for your outbound and return journeys, from $69 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Seattle to St. Louis flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Seattle to St. Louis airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Seattle to St. Louis Flights

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Explore a world of travel with Expedia

*Available to One Key members.