SEA - STL

$84 Find Cheap Flights from Seattle to St. Louis

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Seattle to St. Louis departing on 4/15. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

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.
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Seattle to St. Louis.
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Everything you should know

Cheapest round-trip
$220
Overall average: $358
Southwest
Tue 4/21Sat 4/25
SEA - STL • 2 stops
Cheapest non-stop
$227
Typical prices: $319-$477
Alaska Airlines
Tue 4/14Wed 4/22
SEA - STL • Non-stop
Advice from real travelers
AI-powered summary based on content written by travel experts and KAYAK users. AI can make mistakes.
Use SEA Spot Saver for faster security at Seattle.
Measure wheels for carry-on to avoid extra fees.
Expert advice
Expert advice
+1
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Expert advice
Expert advice
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Top airlines
Cheapest • from $221 (round-trip)
Best reviews • 8.0 score
Airline reviews
Airline reviews
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Airline reviews
Airline reviews
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Nonstop flights
You can fly direct with Alaska Airlines. Average duration is 3h 56m
Direct flights
Direct flights
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Direct flights
Direct flights
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Top layover airports
Cheapest • Avg $198 (round-trip)
Shortest trip • 6h 25m (one-way)
Insights
Insights
Insights
Insights
When to book
in advance
Our data shows that travelers who book at least 4 weeks in advance save around 50% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
Cheapest • 35% price drop
Most popular
Good to know
Good to know
+1
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Good to know
Good to know
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Start a new search
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We hope you love your trip to St. Louis!
Flight Deals
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Expert advice
Flight 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

Tue, Apr 21 - Sat, Apr 25
Southwest Logo
11:40 am - 11:15 pm
SEA
-
STL
9h 35m
2 stops
Southwest Logo
10:35 am - 5:55 pm
STL
-
SEA
9h 20m
2 stops
$220Southwest
Fri, May 1 - Mon, May 4
Frontier Logo
7:12 pm - 7:32 pm
SEA
-
STL
22h 20m
1 stop
Frontier Logo
8:17 pm - 9:49 am
STL
-
SEA
15h 32m
1 stop
$221Frontier
Tue, Apr 14 - Wed, Apr 22
Southwest Logo
11:40 am - 11:15 pm
SEA
-
STL
9h 35m
2 stops
Southwest Logo
5:30 am - 6:00 pm
STL
-
SEA
14h 30m
2 stops
$225Southwest
Thu, Apr 16 - Sat, Apr 25
Frontier Logo
4:20 pm - 11:19 pm
SEA
-
STL
28h 59m
2 stops
Frontier Logo
8:17 pm - 9:27 am
STL
-
SEA
15h 10m
1 stop
$226Frontier
Tue, Apr 14 - Wed, Apr 22
Alaska Airlines Logo
6:02 pm - 11:59 pm
SEA
-
STL
3h 57mnonstop
Alaska Airlines Logo
7:00 am - 9:32 am
STL
-
SEA
4h 32mnonstop
$227Alaska Airlines
Thu, Apr 9 - Mon, Apr 13
Frontier Logo
12:42 pm - 9:48 am
SEA
-
STL
19h 06m
1 stop
Frontier Logo
8:19 pm - 9:27 am
STL
-
SEA
15h 08m
1 stop
$229Frontier
Fri, May 1 - Wed, May 6
Frontier Logo
7:12 pm - 7:32 pm
SEA
-
STL
22h 20m
1 stop
Frontier Logo
6:51 pm - 10:22 am
STL
-
SEA
17h 31m
1 stop
$231Frontier
Tue, Apr 21 - Wed, Apr 22
United Airlines Logo
11:35 pm - 9:25 am
SEA
-
STL
7h 50m
1 stop
United Airlines Logo
6:05 pm - 10:56 pm
STL
-
SEA
6h 51m
1 stop
$232United Airlines
Wed, Apr 15 - Sat, Apr 25
Frontier Logo
8:07 pm - 7:21 pm
SEA
-
STL
21h 14m
1 stop
Frontier Logo
8:23 pm - 9:27 am
STL
-
SEA
39h 04m
2 stops
$233Frontier
Wed, Apr 8 - Wed, Apr 8
Delta Logo
5:30 am - 1:17 pm
SEA
-
STL
5h 47m
1 stop
Delta Logo
6:12 pm - 12:03 am
STL
-
SEA
7h 51m
1 stop
$237Delta
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’s the cheapest day of the week to fly from Seattle to St. Louis?

The average price of all round-trip flights from Seattle to St. Louis clicked on KAYAK for each day over the last 12 months.

If you are looking for a flight deal from Seattle to St. Louis, look for departures on Tuesdays and avoid leaving on a Monday, as it's usually the priciest day. When flying back from St. Louis, Tuesday is the cheapest day to fly and Sunday is the most expensive.

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 January, where tickets cost $237 (return) on average. On the other hand, the most expensive months are December and March, where the average cost of round-trip tickets is $523 and $431 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 $269, 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 4 weeks before departure, which saves you about 50% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 26 weeks before departure.

Expert advice

Expert advice for your flight from Seattle to St. Louis

 
AI-powered summary based on content written by travel experts. AI can make mistakes.
KAYAK teamed up with top travel experts to share the best tips for your journey.
Our travel experts
Yulia Denisyuk

Yulia Denisyuk

Expert on STL

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.

Harriet Baskas

Harriet Baskas

Expert on SEA

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.

Good to know

Low seasonJanuary
Cheapest flight$84
Best time to beat the crowds with an average 35% drop in price.
Most popular time to fly with an average 12% increase in price.
Flight from Seattle to St. Louis

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 travelers who flew the route from Seattle to St. Louis 
Verified travelerFlew with Alaska Airlines
SEA
-
STL
Jul 2025
Give yourself extra time. Love the self check in options.
Verified travelerFlew with Alaska Airlines
SEA
-
STL
Feb 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.

  • What is the cheapest flight from Seattle to St. Louis?

    In the last 3 days, the lowest price for a flight from Seattle to St. Louis was $84 for a one-way ticket and $221 for a round-trip.

  • Do I need a passport to fly between Seattle and St. Louis?

    Even though you are not required to have a passport, keep in mind that an official ID is needed to board the airplane.

  • Which airports will I be using when flying from Seattle to St. Louis?

    On your way to St. Louis, you’ll fly out from Seattle/Tacoma Intl. You’ll be landing at Lambert-St Louis.

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

    Alaska Airlines, JetBlue, Hawaiian Airlines, American Airlines, and Delta 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?

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

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

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

  • Which is the best airline for flights from Seattle to St. Louis, Southwest or Alaska Airlines?

    The two airlines most popular with KAYAK users for flights from Seattle to St. Louis are Southwest and Alaska Airlines. With an average price for the route of $320 and an overall rating of 8.0, Southwest is the most popular choice. Alaska Airlines is also a great choice for the route, with an average price of $397 and an overall rating of 7.9.

  • 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. Booking your flights between Seattle and STL can sometimes prove cheaper using this method.

  • 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

  • Looking for a cheap flight? 25% of our users found flights on this route for $214 or less one-way and $297 or less round-trip.
  • 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

Alaska Airlines

Alaska Airlines

Tuesday

Alaska Airlines

Alaska Airlines

Wednesday

Alaska Airlines

Alaska Airlines

Thursday

Alaska Airlines

Alaska Airlines

Friday

Alaska Airlines

Alaska Airlines

Saturday

Alaska Airlines

Alaska Airlines

Sunday

Alaska Airlines

Alaska Airlines

See more direct flights

Direct returns

Lambert-St Louis to Seattle/Tacoma Intl

Monday

Alaska Airlines

Alaska Airlines

Tuesday

Alaska Airlines

Alaska Airlines

Wednesday

Alaska Airlines

Alaska Airlines

Thursday

Alaska Airlines

Alaska Airlines

Friday

Alaska Airlines

Alaska Airlines

Saturday

Alaska Airlines

Alaska Airlines

Sunday

Alaska Airlines

Alaska Airlines

See more direct flights

Reviews of the top 5 airlines serving 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.
8.0
SouthwestOverall score based on 4319 reviews
8.1Boarding
8.6Crew
7.0Food
7.5Entertainment
8.0Comfort
Airline reviews

Long layover between flights to Long Island from BWI - need better coordination between flights

4.0 OkayKenny, Mar 2026
TPA - BWI
Read more Southwest reviews

Long layover between flights to Long Island from BWI - need better coordination between flights

I elected to pay for the upgrades and found very little difference

The new seating arrangement is so over priced for what you get.

The problem with the seat assignments is that there were a lot of rows in the front that were empty but my row at the back was full. Just not so pleasant.

No food or entertainment, just a quick 40 minute flight. A little bumpy due to Santa Ana winds but pilot has no control over that. Good flight and landing!

Good but I prefer choose your own seat. With the new assigned seats they should board from the back I see no advantage to this new boarding. Just like every other airline

I realize they are still working out kinks with the new boarding process, but by the time I boarded in group 5, most of the bins were full. All airlines should better enforce small bags and jackets going under the seats until everyone has boarded.

WiFi was not working and didn’t have a beverage service

Snacks are always pretzels. Why can't you also offer peanuts ?

Flight boarded late after announcing on time boarding. Flight arrived only a little late despite late departure. Had trouble connecting to WiFi

Departing flight for our weekend trip was cancelled due to weather which meant our return flight was useless. The whole thing was difficult to get support through but Alaska did recover and was able to reimburse us for the flights yesterday. For some reason, Kayak was not kept in the loop, adding to the confusion.

i canceled my return flight package with Alaska Airlines. Customer Service was excellent and assisted me to cancelled both of our reservations and returned the payment in full. that is excellent service and understanding and empathy of the customers' needs. i like Alaska Airlines and recommend AS to everyone.

Never got on because the airline sent the WRONG plane to take us on our first leg of the trip so we missed ALL connecting flights. No help available from anyone at the airline…

The crew inside the airport for Alaska was rude, lazy and incompetent

The flight was extremely smooth, and so was the landing. Great piloting.

Plane was clean, staff was professional and flight was on time. No built in tv was still ok, as programs were offered that could synch to smart phones.

J was in the ER x 3...3 protruding discs...contacted Alaska many many days prior to cancel and request a refund or a credjt.. they only gave me 50 % credit....outrageous seeing how i have a doctors letter....just plain inhuman. AI sucks!

The flight was too short. No snacks or drinks offered.

The flight attendant was friendly and attentive. Although our interaction was brief—- it made a difference. The crew was upfront about turbulence. I like the Maui pretzels.

Everything was good. Please have a wheat free option for snacks in the future.

Perhaps when you’re sitting in 1st class and the crew closes the bathroom for the pilots, there could be a notification other than holding your hands up as a blockade when you get there and you’re told the restrooms are closed please turn around … especially at night when visibility is poor and you’re met by a flight attendants with their arms up

First class is comfortable. Enjoyed a movie and was able to relax compared to coach.

Loved flying First Class. Very comfortable. The seat was amazing. Enjoyed a movie and was able to relax so much better than in coach.

We landed and sat on the tarmac for 45 minutes because they only have one gate at the airport and there was another plane running late so we had to wait

The WiFi was not working. That made for a long flight.

Absolutely no communication on why there's a delay and multiple flight time reschedules. I would have canceled the flight and drove back home if I known it was going to be rescheduled 3 or 4 times.

Another late night flight and MORE men belligerently drinking and yelling. I had to move from first to economy because they were so obnoxious and disruptive. Crazy to go from a cozy chair to cardboard when you were supposed to be in first. Delta allows was too much drinking which leads to belligerent behavior.

I was in first class and literally the men behind me were so aggressively loud I moved myself to economy. This has become so common on Delta - people using audio without headphones, and men on 12am / late night flights drinking and yelling to talk to each other which prevents anyone around them from resting. Pretty crazy to have to move from first to economy (poorer service, less comfort...). Wild wild. Looking into other airlines.

Could not get my connecting flight boarding pass until four hrs before departure! Ver annoying especially since the staff could not explain why!

First flight out and was 85 minutes delayed. Notification came out way too late

The crew were exceptionally nice and accommodating. My wife was tired after the flight from Haneda, Tokyo. They let her sleep and served her dinner later after she woke up, before we landed in PDX.

No charging outlets worked. Other than collecting trash attendants didn’t come around. No one could hear flight attendants announcements during the flight. Seat pads were horrible. Sitting on a board for 5 hours. What happened to Hawaiian airlines comfort, hospitality, and extras? Our pilots did an excellent job trying to minimize turbulence and incredible job in landing in windy conditions.

There was no wifi available at any price -- the plane did not have wifi equipment. Movie choices were blah - hits from the past; nothing recent. The food was blah airplane food. They should have had Mai Tai drinks available as per the Hawaiian Airlines magazine, but they had none onboard.

I like that if they asked you to checked in a bag at the gate they give you priority to board

Horrible food and crew. Crew were laughing and talking loud while people were trying to sleep

Yall need to integrate your system with Alaska more efficiently. They booted me off the first flight because of a discrepancy on your end.

The crew at Hawaiian Airlines was fantastic. Kind and hard working. The pilots were great with giving us all the updates to make sure we were informed.

Very good. Nice plane and we sat in economy plus - bigger seats, more room. They served a meal and snacks, and the meal was an apple stuffed pancake that was very good! The snack for us was a hummus sandwich - also very good. The flight attendants were helpful and nice. They have plenty of movies and shows to watch. My only negative -- they changed our flights around and did not adjust the layovers, so we ended up with a very long and unnecessary layover in Honolulu.

I liked the Starlink WiFi but didn't like how they said they were the only airline to offer a free meal and it turns out to be just a standalone sandwich and then charge for snacks to go with it. Rather have the free snacks like Southwest, but have the option to purchase a decent meal for a 5+ hour flight.

Flight scheduled to take off at 5.55pm but it did not take off until 7pm due to some food delivery delay.

Delay after delay with little communication then AA lost my luggage and at airport would not assist just said scan this QR code to track your luggage and submit a claim. However QR code provided did not work so have to go back to airport

After changing the departure gate 5 times making us mo e from one side of the airport to the other and then back the flight was delayed nearly 2 hours. The male flight attendant had a bad attitude with the guest being condescending, disrespectful with people who were already on edge.

Easy boarding. Rows are smaller but that may be an older and bigger me now :)

It would have been nice if American tried to care.

American Airlines did everything they could with the high Spring Break crowd. I was frustrated to be changed from 1st class to a middle seat at the back of the plane. This has happened before, not sure booking 1st class and paying the extra actually works.

I booked 1st class, my flights were changed and I was sitting in the middle at the back of the plane. A far cry from the 1st class I purchased for my flights. I am grateful I arrived on time.

There was no beverage service and the only time I saw a crew member walk through the cabin is when we were preparing to land.

Our flight was delayed 3 times and this is why I am giving such low reviews. Everything else was okay but being in the airport at 4:30pm for my initial flight at 7pm to not leave until after 9:30pm is insane,

Flights were constantly delayed. CRW took 50 minutes to get bags

Flight has been delayed every time I've ever taken it. Seats uncomfortable. Children behind me yelling the entire flight. Some of this is out of their control but overall just consistently not a great experience.

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

Information on your arrival and departure airports