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Find cheap flights from Seattle to St. Charles from $81

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. Charles departing on 6/14. 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
0 bags
Mon 7/8
Mon 7/15

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Good to know

Low season

January

High season

April

Cheapest flight

$81
Best time to beat the crowds with an average 31% drop in price.
Most popular time to fly with an average 1% increase in price.
Flight from Seattle to St. Louis

When to book flights from Seattle to St. Charles

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

FAQs for booking flights from Seattle to St. Charles

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

    When flying out of Seattle you’ll be using Seattle/Tacoma Intl. St. Charles does not have its own airport so you’ll be flying into nearby Lambert-St Louis airport, which is 7.2 mi away.

  • How long does a flight from Seattle to St. Charles take?

    Direct flights cover the 1,704 miles separating Seattle and St. Charles in about 3h 49m.

  • How many flights are there between Seattle and St. Charles?

    13 direct flights run between Seattle and St. Charles on a daily basis. On average, there are about 95 departures each week.

  • What’s the cheapest day of the week to fly between Seattle and St. Charles?

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

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

    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. Charles.

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

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

    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. Charles 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. Charles?

    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. Charles 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 St. Charles?

    In the last 72 hours, the cheapest one-way ticket between Seattle and St. Charles found on KAYAK was with Frontier for $81. Frontier offered a round-trip connection from $172 and American Airlines from $196.

See more FAQs

Top tips for finding cheap flights from Seattle to St. Charles

  • There is no airport in St. Charles. Instead, you’ll be flying into St. Louis Lambert Airport when flying between Seattle and St. Charles.
  • The cheapest flight from Seattle to St. Charles was found 71 days before departure, on average.
  • Book at least 1 week before departure in order to get a below-average price.
  • High season is considered to be June, July and August. The cheapest month to fly is January.
See more tips

Top 5 airlines serving Seattle to St. Charles

Need help choosing which airline to fly with from Seattle to St. Charles? 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 9236 reviews
8.2Boarding
7.3Food
7.3Entertainment
7.9Comfort
8.6Crew
Airline reviews

The airline was way too cold. We were freezing, I don’t know if that is normal. Overall it was pretty good flight. Always flown Alaska Airlines and I am not changing.

8.0 ExcellentAnonymous, Jun 2024SEA - OAK
Read more about Alaska Airlines reviews

The airline was way too cold. We were freezing, I don’t know if that is normal. Overall it was pretty good flight. Always flown Alaska Airlines and I am not changing.

I was sitting in row 31 and felt bad smell coming from the toilets especially when boarding and exiting not much during the flight.

Great. They got us on an earlier flight. Really appreciated that

I had very little legroom and the only food available was really salty

Offer snacks/meals for people with food sensitivities. HAVE TV SCREENS!

Cabin crew very friendly and pleasant. Flight left late but we didn't know why. Alaska Airlines app was not user friendly -- app wouldn't let us upgrade our seats, but no indication if flight was full. We wound up having to call the airline to request an upgrade and we were told none was available. Waste of time. Baggage retrieval was easy.

The boarding gate is literally just an aisle to the concourse. There is no seating and it's shared with several other airlines. It's crowded, hot, and standing-room only. It's difficult to hear gate announcements over the PA system with too many other carriers crammed into a small space. I've enjoyed flying AA in the past on the west coast, but the BNA single gate experience is horrendous! Never again from BNA to SEA with AA.

It was a partial full flight. But even with a spare seat it was hard to get comfortable More on me being a wide body probably

Our flights using Alaska Airlines went great! All of the flight attendants were very friendly. Big shout out to the pilots for getting us to and from our destinations safely!

I can’t complain. Perhaps passing out headphones, but it was on me to bring my own since I could have used some for my personal device.

Really bad baggage handling. Had my Rimowa bag badly damaged at the latches.

The plane from SNA wouldn’t start after 5 tries. The team gave me an option of flying direct from LAX and giving me a Lyft ride there! Perfect!

Had a broken tray in business class. Crew just shrugged it off.

Everything was great except for the seat. The backrest would not stay in the upright position.

public website still broken for years randomly blocking browsers with privacy options active after loading a page maybe once. check-in on laptop was almost impossible but eventually randomly worked. had to print pass at airport since couldn't get back in to load digital pass on mobile firefox or chrome. red eye flight so smooth onboarding, plenty of room to spread out, easy offboarding. onboard wifi instructions mention vpn can cause problems connecting but fails to also mention private dns. no printed or built in menu list, seems weird to require personal device to point at qr code link for menu which does not even allow direct ordering. people with health condition risk related dietary restrictions trying to avoid for example cholesterol and sugar are left guessing what they can order either way without nutritional info highlights (cranberry juice was minute maid cocktail with as much suger as typical can of soda). tap to pay wasn't working and always seems sketchy to manually enter card info. good movie variety, so limited tv was okay.

Bag drop off was slow and annoying. Only 2 agents at the entire delta desk, and no one directing traffic for what line to be in, many confused people slowed down the process. Boarding was fine. Seats in Delta comfort plus were fine. Snacks were great! Definitely a bonus. The entertainment system was awful — old, slow, not responsive, and completely unable to play games due to some kind of error. But on the other hand, thank you to Delta for the free WiFi. That made it better.

Flight diverted in SD. Later take off in Seattle by 1.3hrs

Mi primera conexión se retrasó por lo cual perdí mi segunda conexión la cual salió adelantada

Crew was not friendly when I went to request a seat change.

There were choices for the snacks. Good choices and tasty lunch and breakfast as well.

No real agent onsite helping you for missing luggage there. Not like the other airline next to UA desk, they have staff attending in their desk assisting answer/helping luggage issue, even after midnight.

Horrible, the flights kept delaying, so it is obvious that we won't be able to make it to the next connection. No easier/real agent on site to help you figure this out. UA agent on other counters refuse to assist you and direct us to use the QR code/call customer service. So inefficient and poor. While technology seems convenient, but it's not the best interest/experience for customers need help while there is active issue need assistance.

After the morning frenzy of 35 min wait through CLT security at 4;30 AM, it was nice to have a smooth pleasant boarding experience. This 6:30 AM flight was not full. We were able to get seated swiftly and took off promptly. Nice touch they distributed the old fashioned headsets with 8 mm jacks. Snacks were decent and arrival was uneventful.

My window shade didn’t work. So I missed coming into my city. ☹️

Flight was delayed in the gate by 5 hours and ultimately cancelled- rebooking service by United agents was terrible

Flight was delayed due to the late arrival of the catering truck, which is quite unacceptable. There was a beverage service, but no pretzel, or cookie, or nuts were served in coach.

Not worth the price of premium class ticket paid, felt more like steerage.

Flighty delayed on boarding - then group 1 had to check their carry on bags but groups 3 and beyond could carry bags on - very inconvenient for weekend business trip with no checked baggage. Then delayed on the runway - before take off. No communication from pilot on why or how long. Wifi/Entertainment didn't work for 4+ flight. Upon arrival, attendants announced wrong carousel for baggage claim - everyone was waiting at the wrong place for their checked bags. This was a mess united!

I had a great flight. Everything went smoothly and the flight arrived early.

The flight and boarding were easy peasy. I was traveling with my 4-year-old, so a smooth boarding experience was especially appreciated. My only piece of feedback is really about where our gate was in O'Hare. They've shoved four gates into a tiny corner of the B terminal and there isn't early enough room or seating for everyone. Not United's problem, but did dent the overall experience.

We had a 2 hour delay. The seats were smaller than most other airlines. The person in front of us wanted to lay back and we had to stop her because she was pressing against my girlfriend’s legs. We had to ask her to sit up and not lay back due to the lack of room.

Everything was fine once we actually got on our flight. It was more then annoying they canceled (delayed) our flight. We lost out on a day of our trip along with money on our stay. Plus we had to book another hotel. So expensive.

This flight was canceled and delayed several times without explanation. The plane was freezing cold and no wifi for messaging. Getting off the plane was terribly unorganized and felt like it took forever….

The flight was delayed several times without explanation. The seats were terribly uncomfortable and wifi isn’t included. All these make for a less than ideal flight.

The flights was delayed by hours and it was the firmest landing I have experienced in my life. My back is still sore.

Internet service was erratic. Crew service was poor and slow. My luggage on this non-stop flight was lost and not recovered

Terrible. I didn’t fly and I had an important meeting the next day.

Equipment swap led to 2+ hour delay on international flight. And to top it off, boarding took forever.

Wretched scheduling - they got themselves into a critical crew situation and didn’t try to address it until 15 minutes before they had to cancel my flight

They cancelled two flight and got us onto another airline, which was also delayed.

Four and a half hour delay in total. What frustrates me most is the poor communication and disorganization.

I appreciated the upgrade to free cary-on bag and seat selection at no charge

FRONTIER SUCKS! The agent downstairs tricked me into booking, just to get to the gate. At the gate, they told me they couldn't help. I then called Customer Service. They and the gate attendants kept blaming each other. Neither side was willing to help the customer.

The agent at check-in was strident, unwelcoming, and condescending to customers ahead of me.

Flight was delay 9hrs and nothing was provided at airport, had to go and get a room to sleep in, paid for Uber back and fort with no offers until we landed back home a 1hr later for a $75 voucher for a future flight.

Didn't like anything..entire crew was very rude to everyone on the flight. Plane old and the trays fall down on you the while time you're flying. Charged more for a carry on bag than for the plane ticket itself. Did make it from point a to point b, but worth the extra money to fly with another airline

9 hours of delay!! Was not able to check my luggage that I paid for!!!

It was delayed 9 hours for operational reasons, despite the plane arriving to the airport on time.

I am very disappointed with Frontier Airlines. They cancelled our flight because they couldn't find a crew member, and then didn't get us to our connecting flight. We had to cancel our whole vacation. We were promised flight and hotel vouchers, but they never sent them.

9hrs delay and didn’t provided anything until after flight landed $75 voucher for fiuture travel no meals or anything.

Book cheap flights from Seattle to St. Charles

Recent round-trip flight deals

8/26Mon
1 stopFrontier
12h 27mSEA-STL
9/3Tue
1 stopFrontier
12h 05mSTL-SEA
$172
6/21Fri
1 stopFrontier
10h 39mSEA-STL
6/24Mon
2 stopsFrontier
19h 18mSTL-SEA
$173
10/1Tue
1 stopAmerican Airlines
7h 57mSEA-STL
10/8Tue
1 stopAmerican Airlines
6h 27mSTL-SEA
$196
8/22Thu
1 stopDelta
5h 59mSEA-STL
8/25Sun
1 stopDelta
7h 27mSTL-SEA
$216
9/3Tue
1 stopDelta
7h 58mSEA-STL
9/9Mon
1 stopDelta
7h 29mSTL-SEA
$232
8/23Fri
1 stopAmerican Airlines
6h 43mSEA-STL
8/27Tue
1 stopAmerican Airlines
10h 26mSTL-SEA
$236
10/1Tue
nonstopAlaska Airlines
3h 50mSEA-STL
10/8Tue
nonstopAlaska Airlines
4h 34mSTL-SEA
$237
8/20Tue
nonstopAlaska Airlines
3h 51mSEA-STL
8/25Sun
nonstopAlaska Airlines
4h 26mSTL-SEA
$257
8/22Thu
2 stopsUnited Airlines
12h 43mSEA-STL
8/26Mon
3 stopsUnited Airlines
14h 54mSTL-SEA
$321
10/1Tue
2 stopsUnited Airlines
11h 37mSEA-STL
10/8Tue
1 stopUnited Airlines
6h 20mSTL-SEA
$412

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Recent one-way flight deals

6/14Fri
1 stopFrontier
10h 39mSEA-STL
$81
6/29Sat
1 stopFrontier
10h 00mSEA-STL
$86
10/5Sat
1 stopAmerican Airlines
9h 20mSEA-STL
$98
10/2Wed
nonstopAlaska Airlines
3h 50mSEA-STL
$119
10/4Fri
1 stopDelta
7h 51mSEA-STL
$124
6/19Wed
1 stopAmerican Airlines
9h 40mSEA-STL
$138
8/30Fri
nonstopAlaska Airlines
3h 51mSEA-STL
$139
10/1Tue
1 stopDelta
7h 51mSEA-STL
$149
10/2Wed
2 stopsUnited Airlines
15h 09mSEA-STL
$158
10/14Mon
1 stopUnited Airlines
32h 08mSEA-STL
$163

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Last minute flights from Seattle to St. Charles

Last minute flight, train and bus deals

6/10Mon
multi-stopAmerican Airlines
6h 34mSEA-STL
6/13Thu
multi-stopAmerican Airlines
7h 52mSTL-SEA
$276
6/12Wed
multi-stopFrontier
28h 33mSEA-STL
6/15Sat
multi-stopFrontier
25h 08mSTL-SEA
$342
6/11Tue
multi-stopAmerican Airlines
6h 34mSEA-STL
6/16Sun
multi-stopAmerican Airlines
8h 31mSTL-SEA
$353
6/12Wed
multi-stopAmerican Airlines
6h 34mSEA-STL
6/15Sat
multi-stopAmerican Airlines
8h 31mSTL-SEA
$357
6/13Thu
multi-stop
9h 44mSEA-STL
6/15Sat
nonstop
4h 28mSTL-SEA
$388
6/13Thu
multi-stopFrontier
9h 44mSEA-STL
6/14Fri
multi-stopFrontier
21h 07mSTL-SEA
$409
6/11Tue
multi-stopUnited Airlines
9h 10mSEA-STL
6/13Thu
multi-stopUnited Airlines
8h 27mSTL-SEA
$412
6/13Thu
multi-stopUnited Airlines
12h 34mSEA-STL
6/15Sat
multi-stopUnited Airlines
14h 05mSTL-SEA
$458
6/12Wed
nonstopAlaska Airlines
4h 01mSEA-STL
6/15Sat
nonstopAlaska Airlines
4h 28mSTL-SEA
$667
6/11Tue
nonstopAlaska Airlines
4h 01mSEA-STL
6/13Thu
nonstopAlaska Airlines
4h 28mSTL-SEA
$827

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Flights to St. Charles