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$104 Cheap Flights from Seattle (SEA) to St. Louis (STL)

View $104 flight on Sat, Nov 7, 2026Opens in a new window

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

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

Prices were available within the past 7 days and start at $104 for one-way flights and $208 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Southwest Airlines
Sat, Nov 7 - Sat, Nov 14
SEA
Seattle
STL
St. Louis
$208 Roundtrip, found 1 hour ago
$208
Roundtrip
found 1 hour ago
Select Southwest Airlines flight, departing Sat, Nov 7 from Seattle to St. Louis, returning Sat, Nov 14, priced at $208 found 1 hour ago
Delta
Tue, Oct 27 - Wed, Oct 28
SEA
Seattle
STL
St. Louis
$211 Roundtrip, found 2 hours ago
$211
Roundtrip
found 2 hours ago
Select Delta flight, departing Tue, Oct 27 from Seattle to St. Louis, returning Wed, Oct 28, priced at $211 found 2 hours ago
Southwest Airlines
Wed, Sep 23 - Sun, Sep 27
SEA
Seattle
STL
St. Louis
$212 Roundtrip, just found
$212
Roundtrip
just found
Select Southwest Airlines flight, departing Wed, Sep 23 from Seattle to St. Louis, returning Sun, Sep 27, priced at $212 just found
Delta
Mon, Oct 26 - Tue, Oct 27
SEA
Seattle
STL
St. Louis
$216 Roundtrip, just found
$216
Roundtrip
just found
Select Delta flight, departing Mon, Oct 26 from Seattle to St. Louis, returning Tue, Oct 27, priced at $216 just found
American Airlines
Sat, Oct 3 - Sat, Oct 10
SEA
Seattle
STL
St. Louis
$217 Roundtrip, just found
$217
Roundtrip
just found
Select American Airlines flight, departing Sat, Oct 3 from Seattle to St. Louis, returning Sat, Oct 10, priced at $217 just found
Southwest Airlines
Tue, Sep 22 - Sun, Sep 27
SEA
Seattle
STL
St. Louis
$217 Roundtrip, found 2 hours ago
$217
Roundtrip
found 2 hours ago
Select Southwest Airlines flight, departing Tue, Sep 22 from Seattle to St. Louis, returning Sun, Sep 27, priced at $217 found 2 hours ago
Delta
Thu, Oct 29 - Fri, Oct 30
SEA
Seattle
STL
St. Louis
$221 Roundtrip, found 2 hours ago
$221
Roundtrip
found 2 hours ago
Select Delta flight, departing Thu, Oct 29 from Seattle to St. Louis, returning Fri, Oct 30, priced at $221 found 2 hours ago
Southwest Airlines
Tue, Nov 3 - Wed, Nov 11
SEA
Seattle
STL
St. Louis
$222 Roundtrip, just found
$222
Roundtrip
just found
Select Southwest Airlines flight, departing Tue, Nov 3 from Seattle to St. Louis, returning Wed, Nov 11, priced at $222 just found
United
Tue, Nov 17 - Wed, Nov 18
SEA
Seattle
STL
St. Louis
$222 Roundtrip, found 1 hour ago
$222
Roundtrip
found 1 hour ago
Select United flight, departing Tue, Nov 17 from Seattle to St. Louis, returning Wed, Nov 18, priced at $222 found 1 hour ago
Frontier Airlines
Sun, Nov 15 - Mon, Nov 23
SEA
Seattle
STL
St. Louis
$263 Roundtrip, just found
$263
Roundtrip
just found
Select Frontier Airlines flight, departing Sun, Nov 15 from Seattle to St. Louis, returning Mon, Nov 23, priced at $263 just found

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 $344
STL
Lambert-St. Louis Intl.
Cheapest
Average driving time to city center20 min
Flights from $344

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

September is typically the cheapest month to fly

From $136 - $221 per traveler.

What you need to know for your flight from Seattle - Tacoma Intl. to Lambert-St. Louis Intl.

Seattle (SEA) to St. Louis (STL) at a glance

Explore a range of options for Seattle to St. Louis flights on this domestic short-haul route. You can choose from both full-service and low-cost carriers to find flights from Seattle that align with your budget and schedule. Whether you're planning to visit St. Louis's iconic landmarks or its vibrant neighborhoods, you'll discover a variety of itineraries to suit your travel needs. Check out the essential details for flights from Seattle-Tacoma International Airport (SEA) to Lambert-St. Louis International Airport (STL).

  • Fastest flight duration: around 4 hours non-stop
  • Route distance: roughly 1,700 miles (2,740 km)
  • Flights per week: around 30+ flights with multiple daily departures on average
  • Typical fares (one-way): economy tickets often range from $90–$385, depending on seasonality and how far ahead you book

Flights from Seattle - Tacoma International Airport (SEA) to Lambert-St. Louis International Airport (STL)

Based on the latest traveler bookings, here are the top airlines preferred for flights from Seattle to St. Louis, typically offering both non-stop and one-stop options. Popular layover points include Salt Lake City International Airport (SLC) with about a 1-hour layover, Denver International Airport (DEN) with roughly a 1-hour layover, and O'Hare International Airport (ORD) with an approximate 1 hour and 15 minutes layover. This variety allows you to balance price, total travel time, and cabin class to create the best travel itinerary.

  • Alaska Airlines: This full-service airline provides both non-stop and one-stop flights, with one-way ticket prices generally between $110 and $440. It represents around 40% of the departures on this route, featuring a standard non-stop flight duration of approximately 4 hours.
  • Delta: Offering one-stop service, this full-service airline has one-way fares that usually fall within the range of $90 to $335. Delta accounts for about 16% of the departures on this route, with an in-flight time of 5 hours and 15 minutes, leading to a total travel time of around 6 hours and 45 minutes, including layover.
  • American Airlines: A full-service carrier that provides both non-stop and one-stop options, American Airlines features one-way fares typically ranging from $90 to $380. This airline makes up about 16% of the flights on this route, with a one-stop journey taking about 5 hours and 15 minutes in the air, totaling roughly 6 hours and 45 minutes overall.
  • Southwest Airlines: Known as a low-cost carrier, Southwest offers both non-stop and one-stop services with one-way fares generally between $90 and $380. It constitutes around 15% of departures on this route, with one-stop travel time of approximately 5 hours and 15 minutes, leading to an overall journey duration of about 6 hours and 45 minutes.
  • United: This full-service airline provides both non-stop and one-stop flights, with one-way ticket prices typically ranging from $90 to $390. United accounts for roughly 10% of flights on this route, with a standard one-stop journey time of 5 hours and 15 minutes, culminating in a total travel time of approximately 6 hours and 45 minutes.

Travelers flying from Seattle to St. Louis can enhance their journey by opting for upgraded seating. Alaska Airlines features first class and business class, while Delta provides first class and premium economy options for a more comfortable experience.

Best time to fly from Seattle (SEA) to St. Louis (STL)

The most popular months for travelers flying from Seattle to St. Louis are March, April, and June, when peak temperatures in St. Louis reach up to 76.1°F in June. If you prefer quieter travel, consider October, the least busy and relatively cheaper time to visit with fewer crowds and temperatures around 58.6°F. For better deals, February usually offers the lowest average one-way fare around $190. Flight availability peaks in June, with approximately 45 flights per week, making it easier to find convenient departure times. February has the fewest flights, with approximately 21 flights per week.

  • Cheapest time to fly: February usually offers good deals with average one-way fare around $190, roughly 13% cheaper than the yearly average.
  • More budget-friendly months to fly: September and January typically offer average one-way fares roughly ranging from $196 to $208.
  • Most flight options: June has the highest number of flights from Seattle to St. Louis, with approximately 45 flights per week, giving you more flexibility in scheduling your trip.
calendar iconMonthtemperature iconTemperaturecrowd level iconDemandflights iconWeekly Flightsprice iconAverage one-way Fare
January31.6°F (-0.2°C)Average24$208
February34.9°F (1.6°C)Average21$190
March46.4°F (8.0°C)Moderately High26$223
April56.1°F (13.4°C)Moderately High30$215
May66.6°F (19.2°C)Average38$212
June76.1°F (24.5°C)Moderately High45$233
July78.6°F (25.9°C)Average42$216
August77.0°F (25.0°C)Average39$223
September70.9°F (21.6°C)Average37$196
October58.6°F (14.8°C)Moderately Low38$217
November46.2°F (7.9°C)Moderately Low28$245
December37.8°F (3.2°C)Moderately Low28$259

*Average one-way fare is based on Expedia flight booking data from January 2025 to April 2026 for the specified route and travel class and may change depending on availability, dates, and demand.

Alternative routes from Seattle (SEA) to St. Louis (STL)

  • Seattle to St. Louis (BFI-STL): Located approximately 6 miles from Seattle - Tacoma International Airport (SEA), Boeing Field Airport (BFI) offers a convenient alternative for travelers.
  • Seattle to St. Louis (SEA-SUS): Spirit of St. Louis Airport (SUS) lies around 16 miles from Lambert-St. Louis International Airport (STL), providing another option for your journey.
  • Seattle to St. Louis (SEA-CPS): Situated roughly 16 miles from Lambert-St. Louis International Airport (STL), St. Louis Downtown Airport (CPS) serves as yet another transit point for flyers.

How to find the best prices for flights from Seattle (SEA) to St. Louis (STL)

Getting some of the best deals on flights from Seattle to St. Louis is all about timing and flexibility. Here are some key tips to help you save:

  1. Best times to book and fly: cheaper fares are usually found when booking 2-8 weeks in advance, which coincides with when most travelers make their reservations. Afternoon departures (12pm-6pm) often offer lower prices, although morning flights (5am-12pm) are the most popular. Additionally, flying on Thursday tends to provide both affordable fares and high demand.
  2. Set up price alerts: stay updated on price changes by using Expedia's Price Tracker. Receive alerts when fares drop for your selected route.
  3. Bundle and save: bundle your flight and hotel to save on Expedia, or unlock a hotel deal after booking your flight.*
  4. Compare flight options: use Expedia's search tool to compare airlines, routes, direct vs. non-direct flights, and flight times. You can also sort by price to find the most affordable options.
  5. Stay flexible with dates: being open to different travel days can sometimes help you find better prices on flights and hotels.
  6. Think about luggage: nowadays, it's important to check the airline's baggage policies to find the best value. That may be paying for an additional carry-on bag or booking a ticket with checked luggage included. Either way, double-check your allowance before confirming your booking to avoid excess baggage fees at the airport.

*Members only. Savings vary and are not available on all bundles. Select hotels.

Arriving at Lambert-St. Louis International Airport from Seattle - Tacoma International Airport

St. Louis welcomes travelers from Seattle with a range of transport options based on price, convenience, and proximity. For departures, Seattle - Tacoma International Airport is roughly a 20-minute drive (covering about 14 miles) from central Seattle. Here's how to reach St. Louis efficiently:

  • Hotel transfer: Transfers offer a convenient way to reach your hotel in St. Louis, with private rides that can be arranged in advance.
  • Car rental: Renting a car from Lambert-St. Louis International Airport is a great option if you plan to explore and sightsee beyond the city. Browse cheap car rentals at Lambert-St. Louis International Airport on Expedia.
  • Taxi/ride-hailing: Taxis and ride-hailing services may be available from designated pickup areas outside the terminal, check locally on arrival.
  • Public transportation: From Lambert-St. Louis International Airport, Lambert Main Terminal Station, a metro station, is conveniently located just 0.1 miles away on foot, providing easy access for travelers looking to use public transport.

Frequently asked questions

How much does a flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) cost?
You can find cheap one-way flights from $104 and cheap return flights from $208 Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) with Expedia. One-way flights generally range between $145 and $916, and roundtrip flights usually range from $265 to $1184. Flight prices vary based on the month and day of the week you want to travel, as well as the airline and how far in advance you book your ticket. Filter your search on Expedia by "Price (lowest to highest)" to see the cheapest fares first, and use the Price Tracking tool to receive alerts when Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) ticket fares go up or down.*Typical price ranges based on flights available on Expedia in the last year. Prices include multi-airline options.
What is the cheapest month to fly from Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
February is the cheapest month to fly from Seattle (SEA) to St. Louis (STL), with average return fares around $323. This price is about 14% lower than the average throughout the year, as travel demand is typically lower during this time. Other budget-friendly months include September and October.*Averages based on flights available on Expedia in the last year.
Which airlines fly direct from Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
Enter SEA to STL and your travel dates, then apply the 'Nonstop' filter to see only direct flights.
What is the cheapest airline that flies from Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
Sun Country Airlines is one of the cheapest airlines offering connecting flights from Seattle - Tacoma Intl. (SEA) to Lambert-St. Louis Intl. (STL), starting from around $285 for a round-trip ticket. Use Expedia's search tool to compare the prices and schedules of airlines that fly this route to find the best option for your plans and budget.*Prices based on flights available on Expedia in the last year.
How do I find cheap flights from Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
To find a cheap flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.), be flexible with your dates. Traveling outside of peak vacation months and booking a mid-week flight can help you save. Early morning and late night flights are often more affordable, too. Expedia allows you to compare flight times, airlines and routes all in one place to find low fares. You can also set up Price Tracking and receive alerts when fares go up or down.
What is the best airline to fly with from Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
The best airline to fly with from Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) will differ from traveler to traveler. If you like to fly early, Alaska Airlines offers early morning flights. If price is the most important factor, WN typically offers the lowest fares. WN offers the most daily flights from SEA to STL, which is great if flexibility is what you value most. The best carrier for this journey could also be the one you have a loyalty membership with, as flying with that airline or another airline within the same alliance could help you collect points or enjoy lounge access.
What is the best time to fly from Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
For your trip from Seattle to St. Louis, February and September are the best months to fly. These months are the cheapest, with return flights averaging around $323. February often has lower travel demand, while September offers pleasant weather, making both months ideal for travel.*Prices based on flights available on Expedia in the last year.
How many flights per day from Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
There are approximately 1 nonstop flights per day from Seattle - Tacoma Intl. (SEA) to Lambert-St. Louis Intl. (STL). For more options, look at flights that include layovers.
What is the earliest flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
The earliest flight from Seattle (SEA-Seattle - Tacoma Intl.) to St. Louis (STL-Lambert-St. Louis Intl.) usually departs at around 12:05 AM, operated by American Airlines. This seasonal service is available in February and March, giving you an early start to your trip. To compare early flights on Expedia, select the "Early Morning" and "Morning" filters in your search.
What are the most popular departure times for flights from Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
The most popular departure times for flights from Seattle (SEA) to St. Louis (STL) are in the early morning, from 6am to 9am. About 29% of passengers prefer this time window. Many major carriers, including Alaska Airlines, United Airlines, and Southwest Airlines, offer flights during this window. This timing works well because it allows you to arrive in St. Louis with plenty of time to start your day.
How long does it take to fly from Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
Flying nonstop from SEA to STL takes around 3 hours 50 minutes, with the route covering approximately 1,705 miles. Flights with a layover typically take 5 hours longer than direct options. Keep in mind that actual flight times can vary due to wind patterns, weather, and air traffic.
Can you fly business or first class from Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
You can fly first class between SEA and STL. First class cabins are available on:

  • American Airlines
  • United Airlines
  • Delta Air Lines

How much is a business class flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
A direct, return business class ticket from Seattle (SEA) to St. Louis (STL) typically costs between $1,153 - $1,593. A non-stop, one-way business class flight is usually around $508 - $633. Prices often fluctuate based on seasonality and how early you book. You may also be able to find a cheaper business class journey between Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) if you opt for a connecting flight.*Prices based on flights available on Expedia in the last year.
How do I earn miles on a Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) flight with Expedia?
It's easy to earn miles on a Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) flight when you book with Expedia. Before you confirm your booking, simply select your frequent flyer program and enter your program number. As a member of One Key™, you can also earn OneKeyCash™* on top of your airline miles when you book with Expedia.*Excludes taxes and fees. OneKeyCash is not redeemable for cash and can only be used on Expedia and other participating brands.
What airports do you fly into for St. Louis from Seattle - Tacoma Intl. (SEA)?
If you're planning to travel to St. Louis from Seattle - Tacoma Intl. (SEA), you can fly into Lambert-St. Louis Intl. (STL) Some flights may connect through major hubs like Denver Intl. (DEN), Harry Reid Intl. (LAS), Sky Harbor Intl. (PHX) before reaching St. Louis. Compare routes and airports on Expedia to find the best flight options for your travel plans.
Is it cheaper to buy a plane ticket from Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) at the last minute?
Typically, booking a last minute flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) will be more expensive than booking in advance. As the departure date approaches, there are usually fewer seats available which can drive up the cost. However, if there's some wiggle room with your travel dates and times, you could bag a cheap last-minute fare.
Is it cheaper to book a Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) flight and hotel package?
Securing a Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) St Louis Vacation Packages is usually cheaper than booking separately. With Expedia, you can enjoy the ease of organizing your travels all in one place. Select from our extensive range of stays and then add flights, activities and car rentals to your booking. Bundle everything together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.)?
If you booked your Seattle, WA (SEA-Seattle - Tacoma Intl.) to St. Louis, MO (STL-Lambert-St. Louis Intl.) flight within the last 24 hours, you may be able to modify or cancel it without any fees. Depending on the airline and the type of ticket you have, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, head to our Customer Service portal if you'd like more 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
$207
Distance
1705 mi
Average flight time
5 hours 56 mins

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 November. 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 2026. You can also book with separate airlines for your outbound and return journeys, from $104 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

*Flight schedules are subject to change.

*Available to One Key members.

 

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