SEA - YXU

$188 Find Cheap Flights from Seattle to London

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 London departing on 10/6. 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

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

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

Cheap Flights from Seattle to London (SEA-YXU)

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

Mon, Aug 25 - Fri, Aug 29
WestJet Logo
7:35 pm - 5:14 amSEA-YXU
6h 39m1 stop
WestJet Logo
8:00 pm - 6:55 pmYXU-SEA
25h 55m1 stop
$345WestJet
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Tue, Aug 26 - Tue, Sep 2
WestJet Logo
7:35 pm - 5:14 amSEA-YXU
6h 39m1 stop
WestJet Logo
6:00 am - 12:59 pmYXU-SEA
9h 59m1 stop
$349WestJet
Find Deal
Fri, Sep 12 - Fri, Sep 19
WestJet Logo
1:15 pm - 5:12 amSEA-YXU
12h 57m2 stops
WestJet Logo
6:00 am - 8:29 pmYXU-SEA
17h 29m1 stop
$355WestJet
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Fri, Sep 26 - Tue, Sep 30
WestJet Logo
1:15 pm - 5:12 amSEA-YXU
12h 57m2 stops
WestJet Logo
6:00 am - 12:59 pmYXU-SEA
9h 59m1 stop
$363WestJet
Find Deal
Sun, Sep 14 - Sun, Sep 21
Air Canada Logo
7:15 am - 9:29 pmSEA-YXU
11h 14m2 stops
Air Canada Logo
6:10 am - 10:59 amYXU-SEA
7h 49m1 stop
$411Air Canada
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Sun, Sep 14 - Sun, Sep 21
Air Canada Logo
7:15 pm - 9:19 amSEA-YXU
11h 04m2 stops
Air Canada Logo
3:50 pm - 9:22 amYXU-SEA
20h 32m2 stops
$423Air Canada
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Sun, Sep 14 - Sun, Sep 21
 Logo
5:30 am - 5:12 amSEA-YXU
20h 42m3 stops
 Logo
6:10 am - 6:36 pmYXU-SEA
15h 26m2 stops
Sun, Sep 14 - Sun, Sep 21
 Logo
9:15 pm - 5:12 amSEA-YXU
28h 57m1 stop
 Logo
8:00 pm - 7:15 amYXU-SEA
14h 15m1 stop
Tue, Aug 26 - Tue, Sep 2
United Airlines Logo
11:54 pm - 3:02 pmSEA-YXU
12h 08m2 stops
United Airlines Logo
6:15 am - 10:59 amYXU-SEA
7h 44m1 stop
$490United Airlines
Find Deal
Tue, Aug 26 - Tue, Sep 2
United Airlines Logo
4:55 pm - 5:07 pmSEA-YXU
21h 12m2 stops
United Airlines Logo
9:55 am - 8:42 pmYXU-SEA
13h 47m2 stops
$505United Airlines
Find Deal
Booking Insights

KAYAK's insights & trends for Seattle to London flights

Get data-powered insights and trends into flights from Seattle to London 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 London?

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

Your flight ticket price will generally be cheaper if you fly to London on a Thursday and more expensive on a Tuesday. On your return trip to Seattle, you should consider flying back on a Saturday, and avoid Mondays for better deals.

Good to know

Cheapest flight$188
Flight from Seattle to London

When to book flights from Seattle to London

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

  • What is the cheapest flight from Seattle to London?

    In the last 3 days, the lowest price for a flight from Seattle to London was $188 for a one-way ticket and $345 for a round-trip.

  • Do I need a passport to fly between Seattle and London?

    Yes

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

    Seattle and London are both served by 1 main airport. You will leave Seattle from Seattle/Tacoma Intl and will be arriving at London.

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

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

  • Which airline alliances offer flights from Seattle to London?

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

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

    The two airlines most popular with KAYAK users for flights from Seattle to London are United Airlines and Air Canada. With an average price for the route of $660 and an overall rating of 7.4, United Airlines is the most popular choice. Air Canada is also a great choice for the route, with an average price of $671 and an overall rating of 7.1.

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

    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 London.

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

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

    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 London with an airline and back to Seattle with another airline. Booking your flights between Seattle and YXU 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 London?

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

Reviews of the top airlines flying from Seattle to London

 
See real verified KAYAK customer reviews for airlines flying from Seattle to London. 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 London? 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 8896 reviews
6.6Food
7.1Entertainment
7.3Comfort
7.7Boarding
8.1Crew
Airline reviews

the delay for 3 hours was understandable due to weather conditions but the flight should’ve provided some on flight compensations or at least provide more food.

4.0 OkayAnna, Jul 2025IAH - YYZ
Read more United Airlines reviews

the delay for 3 hours was understandable due to weather conditions but the flight should’ve provided some on flight compensations or at least provide more food.

Flight was actually on Air Canada. The flight itself was fine. Nothing special. Food was pretty pathetic except for cookies. They offered plenty of food and drinks but just wasn't very good. Even for airline food.

Boarding experience was smooth. Flight attendants were friendly and helpful. Entertainment system on the Houston-Edmonton flight did not function for passengers on the left side of the aisle. On the bird's eye flight from Quito to Houston, they should not serve a meal. No one needs to eat after midnight and it is disturbing for those passengers trying to sleep.

Flight was late as pilot crew had to land at different airport in their previous flight. Passengers boarded and had to wait for pilots inside plane. Series of incomplete and unnecessary announcements by an annoying voice, rather than complete, informative announcements.

Delay and keep changing gates. I have to run around from B to C then to E.

Boarding was a little difficult. The gate area at O'Hare was very small and crowded due to multiple gates in the area. Could not hear the intercom, so had to rely on signage to see when my group was boarding and the signage was blocked by passengers standing in the gate. Flight was great and we arrived in Montreal on time.

My suitcase was completed destroyed. The top part is broken and unusable now.

When I booked it on Kayak it aaid that I wasn't allowed hamd luggage. I called United Airlines and it took them 6 minutes to figure out if I was allowed free hand luggage. Surely something that simple they should be able to tell me instantly.

I do prefer to fly United and have always had excellent service, except for bad weather. Flights are on time and staff is alway curtious and helpful

We were delayed in Toronto on the tarmac for THREE hours with no clear indication as to why except that it was not a safety hazard. Pilot did apologize more than once but even he was unable to explain why exactly we were delayed. I overheard the stewards saying that the captain was very frustrated with the situation as well because he was not able to explain why except it had something to do with water supply or system on the aircraft and now we needed to wait for an engineer to approve the aircraft for flight. It was very frustrating and distressing as a passenger and we should have been given complimentary meals at the very least.

I booked my flight months ago, and checked-in online about 12 hours before the flight. I received an email confirmation of check-in. I had no subsequent communication from Air Canada after my original booking. After arriving at the airport three hours before the flight, as instructed, I waited 90 minutes for an agent to appear to check my bag. I was informed that my flight had been canceled many weeks before, and that flight was no longer being run!! I showed a copy of my check-in confirmation, but no explanation could be found. I was placed on standby for the next flight and the connection. Luckily, those flights were not full and I arrived at my destination. I double checked my email, but I received no update about the flight from Air Canada until the day of the flight.

I was forcefully re-routed to another destination and was delayed a total of 8hours. I have still not received my bags, no one is taking responsibility. The agents at the airport lied to me that I will get to my destination same time as my previous flight where I was forcefully re-routed from.

Flight was delayed by 1.5hrs. Once inside, people had their small handbags on the storage. The crew (male guy) was not helpful in making some space in the storage. Instead, he asked few bags to be checked-in and it was not a great experience. No attempt to help but just followed the things with a straight face. People had their literally small bags and he wouldnt not move from one storage to another even if there was space and would not let us do i as well. Once flight was on, they ran out of Orange juice, really running out of orange juice when the temp were 32.degrees outside. didnt made the sense. Onasking for a extra snack, he made a face as if he was giving me out of his pocket. if the flight was delayed, there could have an attempt to provide something extra incase people did asked.

Our flight was canceled at the last minute. Someone on the flight said the exact same thing happened to her the day before. I will say they helped us book a flight on another airline so that we could still make our vacation with little delay.

We had a very long delay. First the inbound flight took a while, then maintenance, they “fixed it” to then do boarding and leave the gate, and waste a lot of time to have to go back to the gate and eventually deplane. Had to wait for a new aircraft, wait for a gate, and do the whole thing again. Instead of leaving at 9:50am we left until past 1. I could’ve not woken up at 5am, or spend some more time with my family if they gave more grace period of time between flights to give some time in case of any issues. But they have to make all and every dollar possible

Abandoned me in hallway in a wheelchair… which I asked for because I sprained my back. After waiting in the hallway, I decided to walk the rest of the way since someone respecting me up.. My experience with the united was totally the opposite. Wheelchair access, propped swift and save me a lot of grief. Air Canada totally disorganized.

Bad experience boarding and flight got delayed didn’t make it to my next flight

The food on the trip Toronto to Athens could be better: the chicken didn’t taste good.

Conflicting information provided about baggage allowance. One screen said I had a carry on and another said I didnt.

Flight was delayed but the real issue is how long we sat after boarding. Space very limited for an overnight flight and seatbacks didn’t recline so it was almost impossible to sleep.

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

Information on your arrival and departure airports

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