$84 Find Cheap Flights from Seattle to Belleville

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 Belleville departing on 9/6. 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.
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Cheap Flights from Seattle to Belleville (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 Belleville 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 Belleville

Wed, Sep 3 - Fri, Sep 5
United Airlines Logo
7:00 am - 3:44 pmSEA-STL
6h 44m1 stop
United Airlines Logo
5:49 pm - 10:59 pmSTL-SEA
7h 10m1 stop
$174United Airlines
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Wed, Aug 27 - Wed, Sep 3
Delta Logo
9:40 am - 5:47 pmSEA-STL
6h 07m1 stop
Delta Logo
5:30 pm - 10:14 pmSTL-SEA
6h 44m1 stop
$177Delta
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Thu, Sep 25 - Mon, Oct 6
American Airlines Logo
3:00 pm - 11:48 pmSEA-STL
6h 48m1 stop
American Airlines Logo
5:11 am - 12:45 pmSTL-SEA
9h 34m1 stop
$189American Airlines
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Wed, Oct 8 - Sat, Oct 11
American Airlines Logo
2:52 pm - 11:54 pmSEA-STL
7h 02m1 stop
American Airlines Logo
4:34 pm - 12:27 amSTL-SEA
9h 53m1 stop
$197American Airlines
Find Deal
Tue, Aug 26 - Tue, Sep 2
Hawaiian Airlines Logo
8:38 am - 2:39 pmSEA-STL
4h 01mnonstop
Hawaiian Airlines Logo
3:35 pm - 5:54 pmSTL-SEA
4h 19mnonstop
$217Hawaiian Airlines
Find Deal
Sun, Aug 31 - Tue, Sep 9
Hawaiian Airlines Logo
6:03 pm - 11:59 pmSEA-STL
3h 56mnonstop
Hawaiian Airlines Logo
6:00 am - 8:30 amSTL-SEA
4h 30mnonstop
$227Hawaiian Airlines
Find Deal
Sat, Aug 30 - Tue, Sep 2
Southwest Logo
11:10 pm - 9:10 amSEA-STL
8h 00m1 stop
Southwest Logo
8:40 am - 3:20 pmSTL-SEA
8h 40m1 stop
$236Southwest
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Wed, Aug 27 - Wed, Sep 3
Southwest Logo
6:45 am - 5:40 pmSEA-STL
8h 55m2 stops
Southwest Logo
4:35 pm - 11:35 pmSTL-SEA
9h 00m1 stop
$242Southwest
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Fri, Oct 10 - Mon, Oct 20
Alaska Airlines Logo
6:02 pm - 12:03 amSEA-STL
4h 01mnonstop
Alaska Airlines Logo
6:33 am - 9:05 amSTL-SEA
4h 32mnonstop
$249Alaska Airlines
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Mon, Sep 15 - Mon, Sep 22
Alaska Airlines Logo
12:00 pm - 10:59 pmSEA-STL
8h 59m1 stop
Alaska Airlines Logo
6:00 am - 8:30 amSTL-SEA
4h 30mnonstop
$285Alaska Airlines
Find Deal
Useful Info

Good to know

Low seasonJanuary
Cheapest flight$84
Best time to beat the crowds with an average 4% drop in price.
Most popular time to fly with an average 19% increase in price.
Flight from Seattle to St. Louis

When to book flights from Seattle to Belleville

Are your dates flexible? Find out the best times to travel from Seattle to Belleville based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price

Flights from Seattle to Belleville: the best tips from KAYAK users' own experiences

Insights shared by verified travelers who flew the route from Seattle to Belleville 
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 Belleville

  • Which airports will I be using when flying from Seattle to Belleville?

    When flying out of Seattle you’ll be using Seattle/Tacoma Intl. Belleville does not have its own airport so you’ll be flying into nearby Lambert-St Louis airport, which is 26.3 mi away.

  • How long does a flight from Seattle to Belleville take?

    Direct flights cover the 1,704 miles separating Seattle and Belleville in about 3h 56m.

  • How many flights are there between Seattle and Belleville?

    16 direct flights run between Seattle and Belleville on a daily basis. On average, there are about 117 departures each week.

  • What’s the cheapest day of the week to fly between Seattle and Belleville?

    Consider leaving on a Wednesday and avoid Fridays if you are looking for the best rates. For your return to Seattle, you’ll find the best rates on Saturdays and the most expensive ones on Tuesdays.

  • How does KAYAK find such low prices on flights from Seattle to Belleville?

    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 Belleville.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Belleville 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 Belleville?

    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 Belleville 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 Belleville?

    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 Belleville from Seattle up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • Which airlines provide the cheapest flights from Seattle to Belleville?

    In the last 72 hours, the cheapest one-way ticket between Seattle and Belleville found on KAYAK was with United Airlines for $84. United Airlines offered a round-trip connection from $174 and Delta from $177.

Top tips for finding cheap flights from Seattle to Belleville

  • There is no airport in Belleville. Instead, you’ll be flying into St. Louis Lambert Airport when flying between Seattle and Belleville.
  • The cheapest flight from Seattle to Belleville was found 68 days before departure, on average.
  • Book at least 2 weeks before departure in order to get a below-average price.
  • High season is considered to be November, December and January. The cheapest month to fly is September.

Reviews of the top 5 airlines serving Seattle to Belleville

 
Need help choosing which airline to fly with from Seattle to Belleville? 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
Alaska AirlinesOverall score based on 10000 reviews
7.8Comfort
8.1Boarding
8.5Crew
7.1Food
7.1Entertainment
Airline reviews

I was in the middle seat in the last row but that wasn’t their fault. It is why I rated the flight as mediocre, also the landing was a little rough. The good was really good. The self service luggage belt at SEATAC stopped working right when I reached it. I was literally placing my bag on the small belt when the main belt stopped. I understand that it wasn’t just Alaska but the entire side of the terminal. It took the agents about 20 minutes to arrive at a game plan and it certainly wasn’t flawless but they arranged for our luggage to be taken to the plane the old fashioned way by hand. Understandably, the plane was late in leaving. The flight took the proper amount of time and instead of arriving at OAK at 1:45, we got there at 2:30. I took my time getting to baggage claim because I knew it would be late if it was there at all. Sure enough it wasn’t but there was an agent there to greet me and inform me about my luggage. Long story longer, they delivered my luggage to where I was staying which was an hour away from the airport. Alaska has instituted a delivery type tracking system through my email that kept me informed of where my luggage was the whole time. WELL DONE!!

8.0 ExcellentMichael, Jul 2025SEA - OAK
Read more Alaska Airlines reviews

I was in the middle seat in the last row but that wasn’t their fault. It is why I rated the flight as mediocre, also the landing was a little rough. The good was really good. The self service luggage belt at SEATAC stopped working right when I reached it. I was literally placing my bag on the small belt when the main belt stopped. I understand that it wasn’t just Alaska but the entire side of the terminal. It took the agents about 20 minutes to arrive at a game plan and it certainly wasn’t flawless but they arranged for our luggage to be taken to the plane the old fashioned way by hand. Understandably, the plane was late in leaving. The flight took the proper amount of time and instead of arriving at OAK at 1:45, we got there at 2:30. I took my time getting to baggage claim because I knew it would be late if it was there at all. Sure enough it wasn’t but there was an agent there to greet me and inform me about my luggage. Long story longer, they delivered my luggage to where I was staying which was an hour away from the airport. Alaska has instituted a delivery type tracking system through my email that kept me informed of where my luggage was the whole time. WELL DONE!!

Crew was very friendly. Our bags showed up at the carousel within 20 minutes of arrival.

Flight was delayed and hour due to tire issue. First flight of the day, this issue should have been discovered prior to boarding.

Both legs of the trip were delayed about an hour. Planes were new, liked the WiFi availability and entertainment available. Crew was very good. People were happy and helpful. Liked the pilots - they provided updates throughout the flights. Snacks were underwhelming. Drinks were good! Like the smaller sodas and they actually came through the cabin 2x which was great. In Seattle airport the construction caused much confusion for Alaska. Process of printing own tags, etc was chaotic for people who didn’t check in online prior to arrival which in turn caused issues for those who did. Plus airport gates were too small for the number of people flying.

We did have to wait an hour for the runway to be cleared but other than that it was fine.

My seat row didn’t have tray tables which made it pretty difficult to get comfortable on a four hour flight. Good experience outside of that, though.

There was no sitting place in Sea-Tac airport. Even airline didn’t provide any food or dinner. I will never take this airline in my future travel.

Crew was very rude and uncaring. When someone tried to place their bag in overhead bin and they asked for help, crew told them they could not assist. Crew member then told the customer if they couldn’t place into overhead bin on their own, they should have checked in bag. When other customer helped to place the bag in the overhead bin, they were given evil look by crew member and told to hurry back to their uncomfortable middle seat. This was despite the fact that the plane did not leave until 30 minutes later. The flight was ~80% full; when final people boarded, they were forced into middle seats with no room for comfort. There were a handful of emergency row seats unoccupied. When asked if any of the emergency row seats may be used, the crew said that they would cost extra. Normally if a flight is completely boarded and there are open seats, the crew at least gives thought to asking someone if they want to re-locate to the more comfortable seat, especially on a long flight.

I am always uncomfortable about the boarding process. I think every airlines has their own procedures for boarding but all of their procedures are inconvenient because it takes too much time to board. If you board people from back seat to front, I think you can reduce the time to boarding.

Our original fluffy was cancelled. Our substitute flight didn't fly. We lost out on our hotel and car rental. Had to fly out the next morning. Alaska didn't give us any meaningful information. The first flight was scheduled to leave at 4pm and the substitute flight at 9pm. We left the airport at midnight for a hotel. No weather. Beyond disappointed.

southwest just starting charging for luggage. hadnt realized it until it was too late. now out $70 when i couldve bought a carry on if i wouldve known. free bags was one of the only reasons i chose southwest over another airline (the other being no assigned seats, which is apparently also being changed). stupid business decision. wont be flying southwest anymore.

The quality of Southwest Airlines continues to degrade each time I fly with them. If it were not for the free luggage, I would probably choose another airline. Their prices are a little bit competitive, but way too high for the quality of the service. Southwest is not unique in this way. Domestic flight in the United States of America has continued to be a lower and lower quality product. Very sad when you compare the quality of domestic airlines to that of many international airlines around the world.

Very smooth checking in our luggage with a super pleasant SW agent. I enjoyed a fun entertaining movie.

WiFi did not work. For as outrageous as these flights cost, when they’re advertised with certain services/ features they should be in working order

Worst experience I had on Southwest. Still better than most, but the seating was barely tolerable.

The Southwest employees (all two of them) were very nice and cheerful despite the fact the line to self-check a bag (simply drop it off) was hundreds of people long. Thank God I arrived early to the airport because I stood in this line for at least an hour. Once on the flight that had been delayed by an hour, we had no Wi-Fi and thus no entertainment. Finally, I hope the investor strong arm tactics against Southwest pay off in a short-term windfall to your C-Suite because the rest of you are screwed. I have been a faithful Southwest customer for 15 years due to everything you just got rid of. I'm flying to Idaho and Washington in October, both places I used to simply book with Southwest without a second thought now with Frontier (Washington) and United (Idaho) because they offer everything the "new" Southwest does but cheaper and at better times, destinations, etc. This really makes me sad...

It was okay. The plane was delayed from earlier in the day, but they kept updating the departure time, sometimes later, sometimes earlier. That was stressful. Once we finally got on and took off, it was fine. I was supposed to have a connection in Chicago to Los Angeles, and the time for so late I was rebooked to arrive in LA 3 hours late. The departure time to Chicago later became early enough to have taken my original connection and arrive earlier but that wasn't an option.

It was one and half hour late... Not sure if any other experience matters.

Delayed flight. Nicest crew member was a SW pilot flying seated next to me who kindly move to seat the final passenger. Flight extra delayed. My cup of refreshment of ginger ale was so packed with ice it was literally 2 sips.

For my birthday trip this was my second time ever flying, this trip was the best.

My experience on any Delta flight is always overshadowed by the time Delta removed me from a flight for no apparent reason.

Delayed and took off even later than the scheduled delay time

For a 69 year old with health problems I had the worse experience, no wheelchair when I entered a lady told me to sit and wait while a gentleman told me I had to walk to the Delta station, which I did. I had a carry on and a bag, and I was traveling with my service dog, which was on his carrier and the lady charged me for my carry on luggage, beside all the waiting cause of the delay, I had to walk to get my luggage cause no wheelchair showed up, I am so disappointed. I will get in touch with the company. I got home at 3:00 am, not good for my health situation.

Great experience on Delta. Staff from baggage check to flight attendants were very courteous and professional. My only issue was a personal preference for pretzels instead of the chips and cookies that were offered.

There was no problems, just a little uncomfortable with seats that do not lay back a little

Always good but we must do something about people in rows ahead of you that don't put their seats back up when they are suppose to. And It's rough to not be able to even lean over to get something out of my purse.

Flight was delayed, 30+ bags had to be gate checked. Crew were very friendly!

Everything was good until we were boarding our connection flight in Atlanta, we were told to gate check our carry-on, but when we got inside the plane, there was plenty of room in the overhead.

Did not know my son and I had different seating arrangements. He was fine, but it was disappointing.

Flight was canceled, and no effort was made to help with rebooking, no hotel vouchers, no car transportation and minimal food voucher and most places for food were closed by the time the voucher was given. Waited for 3 hours for bags. Simply the worst travel experience I have ever had

The flight was supposed to leave at 7:30pm, but departed 10:50pm. They kept moving departure time out every half hour. It was a 45 minute flight from n Sunday night with great weather.

The crew was great! It was nice to have a pillow and blanket... It gets cold on those flights. I paid extra money to sit where I thought was extra comfort seating, but it wasn't,... So, I was mad a bit about that. I'm hoping our flight home will be better.

Flight got delayed and it was very inconvenient . Had to come with another carrier. Had to spend one more night in San Francisco.

Logging into next flight was an issue as I never received a confirmation code

Alaska airlines is not what I expected Very disappointed Unfriendly Discouraging Very bad customer service, heartbroken trying to explain to them my situation.

I could not check in ahead of time. Kayak did not give me a proper confirmation number to check in.

I loved flying Hawaiian Air! We didn’t pay to sit together, but we were able to anyway. They had usb charging ports and even outlets in some seats. They served a hot sandwich that was not very good, but we were still pleasantly surprised. The staff was very nice. The seats really made my booty hurt but maybe I’m just not used to sitting so long. Also, the AC was really cold even though I was wearing pants, a hoodie, and a light blanket.

A second drink service on a 6 hour flight would have been helpful.

The steward staff was particularly friendly and helpful. They smiled a lot and seemed anxious to be sure we enjoyed the flight.

Everything was good for the price I paid. Crew was very nice.

Couldn’t get the door on the plane to close leading to a nearly 2 hour delay. But, hey at least they didn’t cancel the flight.

The flight was fine and the crew awesome. The problem is ORD and AA. Computers went down, ORD fell apart and a 40 min flight turned into a 3 hour trip. Guess the answer is to not try and fly to ORD after noon. But, as I said, crew was awesome and did everything they could to lesson the flight time.

The flight was fine but the 8 hour delay in Chicago was awful - 5 gate changes and repeated delays without an explanation. No vouchers. Nothing.

Most miserable flight ever. We waited almost 2 hours on the runway because the flight was oversold. American offered $1200 credit. Then there was some nonsense about weight distribution. Ridiculous. No food for 8 plus hours on the flight. I will be writing a letter.

The flight was 2 hour delayed, otherwise everything was excellent. The delay was due to the hourly limit requirement so given that as a reason, I'm happy with the flight!

Not sure the logic of the boarding in Groups. I was loaded first on the aisle. Then the guy in the middle. Then the guy by the window. Constantly holding up the other people boarding behind them with us blocking the aisle and this happened in most of the other rows

To start, I’d like to say that every American Airline personnel I interacted with on the ground, especially flight crew, was very friendly and did their best to help me out. Despite this, however, my experience with the airline was an entire mess. The 7:19 PM flight was heavily delayed due to weather, and pushed to 10:30 AM the next morning. Because of this, I had to spend the night inside of the airport. At some point later in the night, I got an email saying that the flight had been canceled. I called the support number, and the representative on the other line told me that the flight was still on and that I didn’t need to rebook. The next morning, no one came to the gate to open the door for the crew until almost 11 AM. By this time the flight crew had been waiting for over an hour, and they had called management to get someone to open the door for them multiple times. Around 11:30, the gate screen had changed to a different flight. I ended up buying a last minute ticket with Southwest airline just to get to Chicago, because the next flight with American wasn’t until 7:19 pm that day. Now, earlier that morning my suitcase had been sent ahead of me to ORD. I went to baggage claim to ask them if I could have my suitcase forwarded to where I was staying. The representative at SDF baggage claim said they could and put the claim in for me. As I was going back through TSA, I got an email that the airline had found my suitcase, but the next step was to send it BACK to SDF. I called the airline support number again, and I made it clear that my suitcase needed to stay in Chicago and to not come back to SDF. The representative told me that they would hold my suitcase at ORD and that it wasn’t going to be forwarded anywhere. Once I got there, I found that they had loaded my suitcase onto a plane to send it back to SDF. Thankfully, I had gotten to the baggage claim counter in time for them to put in a request to bring my suitcase back up. My refund with the airline is processing already, but because of this entire experience and miscommunication at every turn of the way, I will not book with American Airlines in the future.

The plane was late and then sat on the runway for almost 45 minutes before taking off.

Crew professional. Easy bag drop off. On time. Good entertainment.

Everything was great. Boarding, early departure, early arrival, and deplaning were smooth. Smooth flight.

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