SEA - YXU

$309 Find Cheap Flights from Seattle to London

This is the cheapest round-trip flight price found by a KAYAK user in the last 72 hours by searching for a flight from Seattle to London departing on 10/28. 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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Flight Deals
Booking Insights
Flight 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

Tue, Oct 28 - Tue, Nov 4
 Logo
3:10 pm - 7:12 pmSEA-YXU
25h 02m1 stop
 Logo
5:45 am - 2:31 pmYXU-SEA
11h 46m2 stops
Tue, Oct 28 - Tue, Nov 4
 Logo
3:10 pm - 7:12 pmSEA-YXU
25h 02m1 stop
 Logo
5:40 pm - 10:16 pmYXU-SEA
7h 36m1 stop
Tue, Oct 28 - Tue, Nov 4
Air Canada Logo
8:00 pm - 8:46 amSEA-YXU
9h 46m2 stops
Air Canada Logo
5:45 am - 2:31 pmYXU-SEA
11h 46m2 stops
$323Air Canada
Find Deal
Tue, Oct 28 - Tue, Nov 4
 Logo
10:05 am - 7:12 pmSEA-YXU
30h 07m3 stops
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5:45 am - 2:31 pmYXU-SEA
11h 46m2 stops
Tue, Oct 28 - Tue, Nov 4
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10:05 am - 7:12 pmSEA-YXU
30h 07m3 stops
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8:00 pm - 2:31 pmYXU-SEA
21h 31m3 stops
Mon, Dec 22 - Mon, Dec 29
Air Canada Logo
8:00 pm - 8:46 amSEA-YXU
9h 46m2 stops
Air Canada Logo
5:40 pm - 10:16 pmYXU-SEA
7h 36m1 stop
$595Air Canada
Find Deal
Mon, Dec 22 - Mon, Dec 29
Air Canada Logo
8:15 am - 9:21 pmSEA-YXU
10h 06m1 stop
Air Canada Logo
5:40 pm - 10:16 pmYXU-SEA
7h 36m1 stop
$613Air Canada
Find Deal
Mon, Dec 22 - Mon, Dec 29
Air Canada Logo
8:00 pm - 8:46 amSEA-YXU
9h 46m2 stops
Air Canada Logo
9:25 am - 7:16 pmYXU-SEA
12h 51m2 stops
$686Air Canada
Find Deal
Mon, Dec 22 - Mon, Dec 29
United Airlines Logo
5:02 am - 9:21 pmSEA-YXU
13h 19m2 stops
United Airlines Logo
5:45 am - 9:17 pmYXU-SEA
18h 32m3 stops
$1,589United Airlines
Find Deal

Everything you should know

Top airlines
Air Canada
Cheapest • from $323 (round-trip)
Air Canada
Best reviews • 7.1 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
Cheapest round-trip
$309
Multiple Airlines
Tue 10/28Tue 11/4
SEA - YXU • 1 stop
Cheapest one-way
Multiple Airlines
Mon 9/15
SEA - YXU • multi-stop
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KAYAK searches 100s of sites at once to find you the best travel deals.
We hope you love your trip to London!
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$309
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 $309 for a round-trip ticket.

  • 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.

  • 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 airline 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.
7.1
Air CanadaOverall score based on 10000 reviews
7.8Crew
7.3Boarding
6.8Entertainment
6.3Food
7.1Comfort
Airline reviews

Short flight. Everything was fine except the flight was delayed twice for a total of an hour.

8.0 ExcellentJason, Sep 2025ORD - YYZ
Read more Air Canada reviews

Short flight. Everything was fine except the flight was delayed twice for a total of an hour.

I found the boarding easy and my seat was very comfortable as I had a lot of leg room. I am not too happy that I no longer have lounge access even though I used to get it with my TD credit card.

Flight cancelled. Major disruption to our travel. Do not use Air Canada from KC. To few flights.

There labor disputes cancelled my flight less than 24 hours before my boarding time but there customer service/website was easy enough to navigate and they rebooked me for no upcharge.

Re luggage I carried a backpack only. I did not check any bags in. However there were other passengers with carry on luggage going in the plane. My question is why are others allowed to have a carry on luggage inside the plane? Shouldn’t they have dropped it off at the gate? I’m asking because I could have brought the same thing instead of a backpack only. Please clarify for future reference. Thank you.

Like the service. Very hard to communicate or contact when have problems

Check in staff was incredibly rude and condescending. When I arrived at the gate I had been charged $125 for a checked back. I did have or check a bag. When I brought this to the attention of the staff member who checked me in, she said that she made a mistake and there was nothing she could do about it. I asked her to remove the charge and refund credit card, she said she could not and that I had to call my credit card company to contest the charge. I called Air Canada customer support, was put on hold, after 43 minutes a received a messages stating customer service was overwhelmed with calls and was then hung up on.

Refreshments and Air Hostess was good. Issues with customs in Toronto caused flight to depart and left me behind twice. Vouchers for delayed flight needs to increase.

Long wait to check in at the priority counter in Toronto

I had no communication, receipt etc from Air Canada until hours before flight

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

Information on your arrival and departure airports

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