SEA - STL

Find cheap flights from Seattle to St. Louis

1 adult
1 adult, Economy

KAYAK searches hundreds of travel sites at once for deals on flights to St. Louis

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Seattle to St. Louis, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Seattle to St. Louis, as well as popular online travel agencies
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Booking Insights
Flights Deals

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

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Seattle to St. Louis that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Seattle to St. Louis

Multiple Airlines Logo
SEA-STL
4413 kmmulti-stop
Multiple Airlines Logo
STL-SEA
4413 kmmulti-stop
Multiple Airlines
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Expert advice

Expert advice for your flight from Seattle to St. Louis

 
Snippets provided in this section are AI-generated based on a summarisation of KAYAK-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.
KAYAK teamed up with top travel experts to share the best tips for your journey.
Airports
SEA

Use the SEA Spot Saver for free expedited security screening from 4 a.m. to 10 p.m. at Checkpoints 2, 3, and 5.

Read more about SEAby Harriet Baskas
STL

Take the MetroLink Red Line for convenient access to downtown St. Louis from STL, avoiding rush hour traffic.

Read more about STLby Yulia Denisyuk
Our travel experts
Yulia Denisyuk

Yulia Denisyuk

Expert on STL

Yulia Denisyuk

Yulia Denisyuk

Yulia is a freelance journalist who’s dispatched from 90+ countries. Her work focuses on cultures, adventure trips and air travel, appearing in NatGeo, NYT, CNTraveler, and more. For past assignments, she’s stayed with nomads in Mongolia and learned the art of Imigongo in Rwanda. She’s based in Chicago; in winter she often questions that decision.

Read more
Harriet Baskas

Harriet Baskas

Expert on SEA

Harriet Baskas

Harriet Baskas

Harriet is an award-winning journalist who is happiest in an airport or an unusual museum. Her stories about airports, air travel, and the business of travel have appeared on NBC News, CNBC, USA TODAY, The Points Guy and other outlets. She is the creator of the StuckatTheAirport.com blog and the author of nine books. When not out on the road or exploring the latest airport amenities, she’s home in Seattle getting ready for the next adventure.

Read more
Booking Insights

KAYAK's insights & trends for Seattle to St. Louis flights

Get data-powered insights and trends into flights from Seattle to St. Louis to help you find the cheapest flights, the best time to fly and much more.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Seattle to St. Louis, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Seattle to St. Louis is September, where tickets cost C$ 421 (return) on average. On the other hand, the most expensive months are December and July, where the average cost of round-trip tickets is C$ 648 and C$ 640 respectively.

Can I save money by flying with a layover from Seattle to St. Louis?

The average round-trip price for all non-stop flights, flights with one layover, and flights with two layovers for the route found by users searching on KAYAK in the last 2 weeks.

No, with an average price for the route of C$ 449, prices are generally cheapest when you fly direct.

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

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Seattle to St. Louis, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from Seattle to St. Louis, you should book around 3 weeks before departure, which saves you about 32% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 10 weeks before departure.


Good to know

Low seasonJanuary
Best time to beat the crowds (4% less expensive on average)
Most popular time to fly (19% more expensive on average)

When to book flights from Seattle to St. Louis

Are your dates flexible? Find out the best times to travel from Seattle to St. Louis based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

Flights from Seattle to St. Louis: the best tips from KAYAK users' own experiences

Insights shared by verified travellers who flew the route from Seattle to St. Louis 
Verified travelerFlew with Alaska AirlinesSEA-STLJul 2025
Give yourself extra time. Love the self check in options.
Verified travelerFlew with Alaska AirlinesSEA-STLFeb 2024
Be sure to measure your wheels for carry on my luggage was the correct size but the wheels made it over so had to check my bag wasn't happy about that since you have to pay for checked should at least get one free.

FAQs for booking flights from Seattle to St. Louis

  • Where can I find car rentals from St. Louis Lambert International Airport (STL)?

    The use of car rentals is one of the most efficient methods of connecting travelers from STL Airport to the city center and St. Louis downtown. Car Rental Town-Saint Louis Airport is one car rental agency that provides affordable services to travelers arriving at STL Airport in St. Louis. This agency is located in STL Airport, along terminal 1.

  • How can I connect to St. Louis downtown from STL Airport?

    The use of the Metrolink bus system is the most efficient and inexpensive method of connecting travelers to St. Louis downtown from STL Airport. Travelers connecting to St. Louis downtown from STL Airport pay approximately $4.00 on Metrolink buses. Apart from buses, travelers can also use rental cars to connect to St. Louis downtown from STL Airport. Consider renting a car at Car Rental Town-Saint Louis Airport Agency.

  • Are there kid-friendly amenities on flights from Seattle to St. Louis?

    The availability of on-demand kid-friendly entertainment options on American Airlines makes it the most preferred airline for travelers flying from Seattle to St. Louis in the company of their kids. This airline offers free in-flight WI-FI services, which allows your kids to stream their favorite video games, TV shows, and music albums, eliminating boredom.

  • Which hotel can I stay in from STL Airport in St. Louis?

    There are several hotels where travelers landing at STL Airport can stay. One hotel that is easily accessible to travelers from STL Airport is the Quality Inn Airport. This hotel is located along Natural Bridge Rd, St. Louis, and it provides free airport shuttle services to customers.

  • Which airlines offer Wi-Fi service onboard planes from Seattle to St. Louis?

    Alaska Airlines, Hawaiian Airlines, JetBlue, and American Airlines offer inflight Wi-Fi service on the Seattle to St. Louis flight route.

  • Which aircraft models fly most regularly from Seattle to St. Louis?

    The Boeing 737 is the aircraft model that flies most regularly on the Seattle to St. Louis flight route.

  • Which airline alliances offer flights from Seattle to St. Louis?

    oneworld, and Star Alliance are the airline alliances operating flights between Seattle and St. Louis, with oneworld being the most commonly used for this route.

  • On which days can I fly direct from Seattle to St. Louis?

    There are direct flights from Seattle to St. Louis on a daily basis.

  • How does KAYAK find such low prices on flights from Seattle to St. Louis?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Seattle to St. Louis.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Seattle to St. Louis?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to St. Louis from Seattle is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Seattle to St. Louis?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to St. Louis with an airline and back to Seattle with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Seattle to St. Louis?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to St. Louis from Seattle up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

KAYAK’s top tips for finding a cheap flight from Seattle to St. Louis

  • Despite having other airports that serve similar flights from Seattle to St. Louis, like Renton Municipal Airport and King County International Airport, travelers from Seattle prefer using Seattle-Tacoma International Airport (SEA) as their departure airport to St. Louis. This airport is widely preferred due to the availability of several cheaper means of transport that connect travelers from the city center and Seattle downtown to the airport, such as taxis, buses, and airport shuttles.
  • Travelers who plan to catch the earliest flight that departs SEA Airport for St. Louis should consider spending their night in a nearby hotel. One hotel that guarantees travelers quick access to SEA Airport is the DoubleTree by Hilton Hotel Seattle Airport. This hotel is located along International Blvd, Seattle, a 4min drive from SEA Airport and offers airport shuttle services.
  • Are you planning to travel from Seattle to St. Louis in the company of a person with reduced mobility? Worry no more. SEA Airport offers curb-to-aircraft services to persons with reduced mobility. All airlines serving flights from SEA Airport to St. Louis, like American Airlines, Qatar Airways, and Southwest, have deployed personnel across the airport to assist persons with reduced mobility.
  • Travelers who wish to shop before taking a flight from Seattle to St. Louis shouldn’t get worried. SeaTac Shopping Mall is one shopping mall that offers quality and affordable products to travelers flying from SEA Airport in Seattle. This shopping mall is located along International Blvd, SeaTac, just a walking distance from SEA Airport.
  • If you plan to take care of your stomach and have some rest as you wait for your flight from SEA Airport to St. Louis, consider visiting Dish D'lish Restaurant. Dish D'lish is one restaurant that offers the best food at an affordable price to travelers at SEA Airport as they wait for their flights to St. Louis.

Prefer to fly direct from Seattle to St. Louis?

 
Direct data is based off flight results for the next 60 days. Find direct flights from all airlines flying direct from Seattle/Tacoma Intl to Lambert-St Louis.
Find which airlines fly direct from Seattle/Tacoma Intl Airport to Lambert-St Louis Airport, which days they fly and book direct flights.

Direct departures

Seattle/Tacoma Intl to Lambert-St Louis

Monday

Air Tahiti Nui,Alaska Airlines,American Airlines, +5 more

Air Tahiti Nui,Alaska Airlines, +6 more

Tuesday

Air Tahiti Nui,Alaska Airlines,American Airlines, +4 more

Air Tahiti Nui,Alaska Airlines, +5 more

Wednesday

Air Tahiti Nui,Alaska Airlines,American Airlines, +4 more

Air Tahiti Nui,Alaska Airlines, +5 more

Thursday

Air Tahiti Nui,Alaska Airlines,American Airlines, +6 more

Air Tahiti Nui,Alaska Airlines, +7 more

Friday

Air Tahiti Nui,Alaska Airlines,American Airlines, +5 more

Air Tahiti Nui,Alaska Airlines, +6 more

Saturday

Air Tahiti Nui,Alaska Airlines,American Airlines, +6 more

Air Tahiti Nui,Alaska Airlines, +7 more

Sunday

Air Tahiti Nui,Alaska Airlines,American Airlines, +6 more

Air Tahiti Nui,Alaska Airlines, +7 more

See more nonstop flights

Direct returns

Lambert-St Louis to Seattle/Tacoma Intl

Monday

Air Tahiti Nui,Alaska Airlines,American Airlines, +5 more

Air Tahiti Nui,Alaska Airlines, +6 more

Tuesday

Air Tahiti Nui,Alaska Airlines,American Airlines, +3 more

Air Tahiti Nui,Alaska Airlines, +4 more

Wednesday

Air Tahiti Nui,Alaska Airlines,American Airlines, +4 more

Air Tahiti Nui,Alaska Airlines, +5 more

Thursday

Air Tahiti Nui,Alaska Airlines,American Airlines, +5 more

Air Tahiti Nui,Alaska Airlines, +6 more

Friday

Air Tahiti Nui,Alaska Airlines,American Airlines, +4 more

Air Tahiti Nui,Alaska Airlines, +5 more

Saturday

Air Tahiti Nui,Alaska Airlines,American Airlines, +5 more

Air Tahiti Nui,Alaska Airlines, +6 more

Sunday

Air Tahiti Nui,Alaska Airlines,American Airlines, +5 more

Air Tahiti Nui,Alaska Airlines, +6 more

See more nonstop flights

Reviews of the top airline flying from Seattle to St. Louis

 
See real verified KAYAK customer reviews for airlines flying from Seattle to St. Louis. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Seattle to St. Louis? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
5.9
FrontierOverall score based on 3237 reviews
6.7Crew
6.1Boarding
5.6Comfort
4.5Entertainment
4.7Food
Airline reviews

Boarding in Orlando was not good. Giant mob at the gate, should have been lines.

8.0 ExcellentJim, Jul 2025MCO - LAS
Read more Frontier reviews

Boarding in Orlando was not good. Giant mob at the gate, should have been lines.

Decent clean onboard experience. Okay discount airline experience. Unfortunately, any customer service interactions are difficult and unhelpful. There is no service. Also, a premium seat only gets you premium boarding if you line up first. Once they start general boarding you must go to the back of the line. Not very premium

baggage clamed had to wait over a hour and half for all people on my flight it was terrible

The ticketing agents were rude but then we had a great gate agent very nice we had to ride a buss out to where the plane was parked but it was in some back corner of the airport when we got to the plane the captain who was great btw was cleaning the plane because the same rude ticketing agent told them they we not contracted to vacuum the plane. The ride to las Vegas was fine We had a connecting flight to Dallas. The flight was fine but when we arrived in Dallas everyone who flew on any frontier airlines the picked up bags from baggage claim D15 had to wait over a hour for their bags to start we arrived at 11:30pm ish to the gate we didn't leave the baggage clamed till 12:50 am very not happy and i used to fly frontier 4 times a week for work in Denver i will not be using them again

I was 2 hr arrive in the airport and 45 min in the line . After take to my turn . The agent tell me I’m later . I can not board . So my vacation was going to the floor . Just for their bad customer service agent in the airline

Frontier Airlines was AWFUL. I was an hour early for my flight and the lady refused to check me in. I had to purchase a whole new ticket with a different airline.

My flight was canceled I was promised a reginf still not received.

Late, terrible communication, horrible planning of passenger seating until the literal last minute. One of the worst flying experiences of my life. Y'all suck

Both legs of the flight were changed. The day of the flight and length of the trip.

First of all, we never got on the connecting flight to Denver. They delayed our flight for two hours. If we would have gotten on that flight, we would have been stuck in Denver for 13 hours. So we re- routed our flight for a straight through flight to Oklahoma two days later. THEN, they delayed that flight for two hours. After that we were able to finally get on our flight and come home. Frontier Airlines - one of the worst airlines I have ever been on.

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

Information on your arrival and departure airports

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