YXU - SEA

C$ 343 Find Cheap Flights from London to Seattle

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from London to Seattle departing on 16/6. 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.
1 adult
1 adult, Economy, 0 bags

KAYAK searches hundreds of travel sites at once for deals on flights to Seattle

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from London to Seattle, 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 London to Seattle, as well as popular online travel agencies
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Everything you should know

Cheapest round-trip
C$ 573
WestJet
Sun 8/3Wed 11/3
YXU - SEA • 1 stop
Cheapest one-way flights
C$ 343
WestJet
Tue 16/6
YXU - SEA • 1 stop
Top airlines
WestJet
Cheapest • from C$ 573 (round-trip)
United Airlines
Best reviews • 7.4 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
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Flight Deals
Booking Insights
Flight Deals

Cheap Flights from London to Seattle (YXU-SEA)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from London to Seattle 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 London to Seattle

Sun, 8 Mar - Wed, 11 Mar
WestJet Logo
8:10 p.m. - 2:19 p.m.
YXU
-
SEA
21h 09m
1 stop
WestJet Logo
3:10 p.m. - 6:35 a.m.
SEA
-
YXU
12h 25m
1 stop
C$ 573WestJet
Sat, 2 May - Sat, 9 May
WestJet Logo
6:15 a.m. - 7:35 a.m.
YXU
-
SEA
28h 20m
2 stops
WestJet Logo
7:35 p.m. - 5:25 a.m.
SEA
-
YXU
6h 50m
1 stop
C$ 586WestJet
Sun, 8 Mar - Wed, 11 Mar
WestJet Logo
8:10 p.m. - 10:25 a.m.
YXU
-
SEA
17h 15m
2 stops
WestJet Logo
3:10 p.m. - 6:35 a.m.
SEA
-
YXU
12h 25m
1 stop
C$ 619WestJet
Sat, 2 May - Sat, 9 May
Multiple Airlines Logo
6:15 a.m. - 7:52 p.m.
YXU
-
SEA
16h 37m
1 stop
Multiple Airlines Logo
7:35 p.m. - 5:25 a.m.
SEA
-
YXU
6h 50m
1 stop
C$ 630Multiple Airlines
Sun, 8 Mar - Wed, 11 Mar
WestJet Logo
8:10 p.m. - 10:25 a.m.
YXU
-
SEA
17h 15m
2 stops
WestJet Logo
3:10 p.m. - 6:35 a.m.
SEA
-
YXU
12h 25m
1 stop
C$ 648WestJet
Sun, 8 Mar - Wed, 11 Mar
WestJet Logo
8:10 p.m. - 2:19 p.m.
YXU
-
SEA
21h 09m
1 stop
WestJet Logo
3:10 p.m. - 6:35 a.m.
SEA
-
YXU
12h 25m
1 stop
C$ 733WestJet
Sun, 8 Mar - Wed, 11 Mar
Air Canada Logo
5:10 a.m. - 2:01 p.m.
YXU
-
SEA
12h 51m
2 stops
Air Canada Logo
8:00 p.m. - 8:46 a.m.
SEA
-
YXU
9h 46m
2 stops
C$ 737Air Canada
Sun, 8 Mar - Wed, 11 Mar
Air Canada Logo
5:10 a.m. - 2:01 p.m.
YXU
-
SEA
12h 51m
2 stops
Air Canada Logo
8:00 p.m. - 8:46 a.m.
SEA
-
YXU
9h 46m
2 stops
C$ 741Air Canada
Sun, 8 Mar - Wed, 11 Mar
WestJet Logo
8:10 p.m. - 10:25 a.m.
YXU
-
SEA
17h 15m
2 stops
WestJet Logo
3:10 p.m. - 6:35 a.m.
SEA
-
YXU
12h 25m
1 stop
C$ 745WestJet
Sat, 2 May - Sat, 9 May
Air Canada Logo
9:30 a.m. - 6:30 p.m.
YXU
-
SEA
12h 00m
2 stops
Air Canada Logo
7:20 p.m. - 8:53 a.m.
SEA
-
YXU
10h 33m
2 stops
C$ 760Air Canada
Booking Insights

KAYAK's insights & trends for London to Seattle flights

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

Which airlines provide the cheapest flights from London to Seattle?

The cheapest round-trip price for the route for each airline clicked by KAYAK users in the last 72 hours.

In the past 3 days, the cheapest round-trip tickets from London to Seattle were found on WestJet (C$ 573) and Air Canada (C$ 737).

Good to know

Low seasonMay
Cheapest flightC$ 343
Best time to beat the crowds (35% less expensive on average)
Most popular time to fly and prices are also 35% lower on average.
Flight from London to Seattle

When to book flights from London to Seattle

Are your dates flexible? Find out the best times to travel from London to Seattle 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.

FAQs for booking flights from London to Seattle

  • What is the cheapest flight from London to Seattle?

    In the last 3 days, the lowest price for a flight from London to Seattle was C$ 343 for a one-way ticket and C$ 573 for a round-trip.

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

    London airport is called London and the only airport in Seattle is Seattle/Tacoma Intl.

  • Which aircraft models fly most regularly from London to Seattle?

    We unfortunately don’t have that data for this specific route.

  • Which airline alliances offer flights from London to Seattle?

    Star Alliance is the only airline alliance operating flights between London and Seattle.

  • Which is the best airline for flights from London to Seattle, United Airlines or WestJet?

    The two airlines most popular with KAYAK users for flights from London to Seattle are United Airlines and WestJet. With an average price for the route of C$ 289 and an overall rating of 7.4, United Airlines is the most popular choice. WestJet is also a great choice for the route, with an average price of C$ 391 and an overall rating of 7.2.

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

    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 London to Seattle.

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

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

    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 Seattle with an airline and back to London with another airline.

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

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

Reviews of the top 3 airlines flying from London to Seattle

 
See real verified KAYAK customer reviews for airlines flying from London to Seattle. 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 London to Seattle? 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.
7.4
United AirlinesOverall score based on 9219 reviews
8.1Crew
7.7Boarding
7.3Comfort
6.6Food
7.1Entertainment
Airline reviews

It was great. There were some issues prior to takeoff. The weather was poor so we had to go through deicing, and we were delayed a bit by the pilots' concern about one of the engines, but that's aviation. The pilots handled everything with aplomb, and kept us apprised

10.0 ExcellentAnonymous, Jan 2026
YOW - IAD
Read more United Airlines reviews

It was great. There were some issues prior to takeoff. The weather was poor so we had to go through deicing, and we were delayed a bit by the pilots' concern about one of the engines, but that's aviation. The pilots handled everything with aplomb, and kept us apprised

Reliable, nice crew, I fly often on that flight and I like it all.

l really enjoy very much the flight was very pleasant

The Sears in the 800s are not too good perfect Airbus why cant the new 737 fix that

Quick and seamless boarding. No entertainment but fast Starlink wifi for this short trip and the staff was really friendly.

I dread trans-Pacific flights. They are very long. This was my first time on Universal, and it was my best crossing ever. The staff were professional, the hospitality was great, and the food was delicious. The entertainment system filled the long flight hours. I will seek out Universal flights from now onwards. 🙂

The food quality sucks. One must starve if they do not eat flesh Or wheat based products Some variety would be expected. The trivial amount of snacks and or food is inhumane

We Left Calgary 1/2 hour late and that made for a tight connection in Denver. After arriving everything was done to help us make our connection. That was a great effort. Thank You United

Efficient all round, very good crew. Short flight so the food, of course, was just snacks

Overall, it was good. I was seating next to a wonderful lady and did not notice how time flew. Thanks

Flight left on time. The crew was very friendly. I had to buy a proper meal. Small cookie and a drink just doesn’t cut it for a 4.5 hours flight.

Experience was good, the wifi hook up is somewhat tough

I will not be flying with westjet again. I was uncomfortable in my seat. The position made my back hurt so bad. My wife was able to fit the seatbelt around her with out an extension but was unable to put the tray table down or fit in the seat for that matter. Our bag was smashed and I spent two hours trying to fill out the application for a damaged bag before I gave up. The 80 photos I took would not work and nothing telling me the format to upload them as.. I made the mistake of unpacking the bag before taking photos so no claim for me. Next trip to Canada I will have to use air Canada.

They lost my bag. Hopefully it will be here tomorrow.

My luggage was damaged 1 wheel was out I can't find it nowhere

Took 3 hours to check in and drop off our suitcases. Half of the passengers were still in line by boarding time. The computer systems and staff were very slow. Staff were also disorganized and kept allowing later flights to skip lines. Suitcases were piling on that several other passengers didn't get their suitcases. Then, we were sitting in the plane for 2 hours and were told that the flight was overbooked. We missed our connecting flight and had to fly the following day but with a stop over. Good thing ONE WestJet customer rep was pleasant and actually knew how to do her job when we wanted to rebook to a direct flight. Thank you to Kim at Toronto airport. Terrible experience at PUJ. Won't go back to Dominican Republic.

Great seats, super comfortable, but no in flight entertainment which was a let down

Airplane is too small. Crew, especially the flight attendant who looked after our area, was not at all friendly and a touch authoratative. She may have been the most gruff flight attendant i've come across in 40 years of business travel

I when to Jamaica for my dad funeral and I did not get my luggage from westjet . I add to buy clothes putting me financial debt i did no want to be in Westjet did not call me to apologize are to inquire about my luggage I am still angry about it

Ground staff was not helpful, but staff at the business counter were excellent.

My seat was covered in vomit and I will be reaching out to Air Canada

It's kindof ridiculous that your system is even asking me about this since my flight was canceled and I wasn't rescheduled.

3 hr delay at the gate while they were doing maintenance. Next time, do not board passengers while maintenance is being performed

Digital check in is very poor with air canada compaired to other airlines

Baggage delayed we had to catch our cruise without any clothes 😒

Air Canada Rouge is great. Toronto Airport is the usual nightmare

Good but need to be better with the flight times.

The staff was great and made the long trip easy peasy!

Air Canada cancelled our flight and reschedule it 26 hours later that completely interrupted my family's long waited Japan trip, it wasn't due to natural reason such as weather but under the company's control. On the day we wasted 9 hours of our time from 6am to 3pm, including a few hours in the customer counter waiting for supervisor to handle our rescheduling. When we came to the counter for rebooking help there were at least 4 employees on the counter but we were told they were not trained to handle customer rebooking, we were also told the supervisor could come 10:30 to handle our rebooking, but she showed up more than one hour later, the end result was exactly the same so the few hours we spent waiting for her was completely wasted; We already prepaid hotel and all the tickets for the our stay in Tokyo so all of the cost for the first day is completed wasted; The $80 meal voucher issues was far less than our financial loss due to the financial cancellation, and it was not surprisingly invalid (as Your company screw up everything possible along the flight), the vouchers were supposed to last 72 hours, when we tried to used it at our lounge next day less than 24 hours from its issuing at a designated restaurant, the worker there couldn't scan the vouchers after multiple tries on all 4 vouchers issued, so we had to pay the food from our own money; For the two return flights they were also full of unfortunate events that caused bad experience and further delay and waste of our time, both flights departed late and the last leg had another significant delay of more than half an hour after touchdown, the gate was for some reason not available so we waited more than half an hour, when we got out of plane it was almost one hour later than the supposed arrival time; The gate you arranged is the farthest in Vancouver airport, also was the luggage pickup location in Seattle airport; We also called customer service for rescheduling help and after a long time wait (more than an hour) we got a call back but the CS representative was equally clueless and unhelpful. Other than a fatal crash, your company couldn't do anything right and provided the worst service possible among the tons of flights we have taken in our lives.

The free Wi-fi for Aeroplan members was a great touch. The time passed quickly. I found the seats seemed a little closer together than I remember. Not Air Canada's fault, but we were about 20 minutes late landing because the airport was too busy. We had to circle around for a while. The boarding and disembarking went very smoothly.

Everything you need to know for your flight from London to Seattle

Information on your arrival and departure airports