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Cheap flights from Seattle to London from C$ 367

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Seattle to London departing on 28/10. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Find the cheapest flights from Seattle to London

Cheap round-trip flights

Delta Logo
5:35 p.m. - 11:20 a.m.SEA-LHR
9h 45mdirect
Delta Logo
6:20 a.m. - 2:20 p.m.LHR-SEA
15h 00m1 stop
C$ 705Delta
Find Deal
Tue, 30 Sep - Fri, 31 Oct
Delta Logo
8:20 p.m. - 12:50 p.m.SEA-LHR
9h 30mdirect
Delta Logo
6:20 a.m. - 11:25 a.m.LHR-SEA
13h 05m1 stop
C$ 706Delta
Find Deal
Tue, 28 Oct - Tue, 4 Nov
Icelandair Logo
2:35 p.m. - 10:55 a.m.SEA-LGW
12h 20m1 stop
Icelandair Logo
3:40 p.m. - 9:10 p.m.LGW-SEA
13h 30m1 stop
C$ 707Icelandair
Find Deal
Fri, 6 Mar - Sun, 29 Mar
Logo
1:30 p.m. - 9:50 a.m.SEA-LHR
12h 20m1 stop
Logo
6:20 a.m. - 12:25 p.m.LHR-SEA
13h 05m1 stop
C$ 711
Find Deal
Wed, 1 Oct - Thu, 30 Oct
Logo
8:30 a.m. - 7:15 a.m.SEA-LHR
38h 45m2 stops
Logo
2:10 p.m. - 2:16 p.m.LHR-SEA
32h 06m1 stop
C$ 714
Find Deal
Sat, 4 Oct - Tue, 21 Oct
Icelandair Logo
7:00 p.m. - 2:40 p.m.SEA-LGW
11h 40m1 stop
Icelandair Logo
11:55 a.m. - 5:00 p.m.LGW-SEA
13h 05m1 stop
C$ 717Icelandair
Find Deal
Wed, 1 Oct - Tue, 4 Nov
United Airlines Logo
4:35 p.m. - 7:40 a.m.SEA-LHR
31h 05m1 stop
United Airlines Logo
10:50 a.m. - 4:59 p.m.LHR-SEA
14h 09m1 stop
C$ 717United Airlines
Find Deal
Sat, 27 Sep - Fri, 10 Oct
United Airlines Logo
6:31 a.m. - 7:55 a.m.SEA-LHR
18h 24m1 stop
United Airlines Logo
6:50 a.m. - 10:29 p.m.LHR-SEA
22h 39m2 stops
C$ 721United Airlines
Find Deal
Wed, 11 Mar - Wed, 18 Mar
British Airways Logo
1:30 p.m. - 6:50 a.m.SEA-LHR
9h 20mdirect
British Airways Logo
9:50 a.m. - 11:35 a.m.LHR-SEA
9h 45mdirect
C$ 781British Airways
Find Deal
Tue, 14 Oct - Mon, 20 Oct
British Airways Logo
8:20 p.m. - 1:40 p.m.SEA-LHR
9h 20mdirect
British Airways Logo
9:50 a.m. - 11:35 a.m.LHR-SEA
9h 45mdirect
C$ 785British Airways
Find Deal
Sat, 4 Oct - Thu, 16 Oct

Delta flights from Seattle to London

Our best Delta deals on Seattle to London flight tickets
Delta
30 Sep
SEA5:35 p.m.Seattle/Tacoma Intl
9h 45m
LHR11:20 a.m.London Heathrow
31 Oct
LHR6:20 a.m.London Heathrow
15h 00m
1 stop
SEA2:20 p.m.Seattle/Tacoma Intl
C$ 705
Find similar
Delta
28 Oct
SEA8:20 p.m.Seattle/Tacoma Intl
9h 30m
LHR12:50 p.m.London Heathrow
4 Nov
LHR6:20 a.m.London Heathrow
13h 05m
1 stop
SEA11:25 a.m.Seattle/Tacoma Intl
C$ 706
Find similar
Delta
1 Oct
SEA8:25 p.m.Seattle/Tacoma Intl
9h 50m
LHR2:15 p.m.London Heathrow
14 Oct
LHR11:45 a.m.London Heathrow
32h 05m
1 stop
SEA11:50 a.m.Seattle/Tacoma Intl
C$ 707
Find similar

United Airlines flights from Seattle to London

Our best United Airlines deals on Seattle to London flight tickets
United Airlines
27 Sep
SEA4:35 p.m.Seattle/Tacoma Intl
31h 05m
1 stop
LHR7:40 a.m.London Heathrow
10 Oct
LHR10:50 a.m.London Heathrow
14h 09m
1 stop
SEA4:59 p.m.Seattle/Tacoma Intl
C$ 717
Find similar
United Airlines
11 Mar
SEA6:31 a.m.Seattle/Tacoma Intl
18h 24m
1 stop
LHR7:55 a.m.London Heathrow
18 Mar
LHR6:50 a.m.London Heathrow
22h 39m
2 stops
SEA10:29 p.m.Seattle/Tacoma Intl
C$ 721
Find similar
United Airlines
1 Oct
SEA7:15 a.m.Seattle/Tacoma Intl
15h 15m
1 stop
LHR6:30 a.m.London Heathrow
14 Oct
LHR8:30 a.m.London Heathrow
21h 15m
1 stop
SEA9:45 p.m.Seattle/Tacoma Intl
C$ 725
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from Seattle to London that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 96,600 searches. Data last updated 15 September 2025.
Use the filters below to find and compare flights from Seattle to London that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 30/9

5:35 p.m.-11:20 a.m.

Nonstop9h 45m

London Heathrow

Fri 31/10

6:20 a.m.-2:20 p.m.

1 stop15h 00m

C$ 705

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 28/10

8:20 p.m.-12:50 p.m.

Nonstop9h 30m

London Heathrow

Tue 4/11

6:20 a.m.-11:25 a.m.

1 stop13h 05m

C$ 706

SeattleLondon

SEA - LGW

SEALGW

Seattle/Tacoma Intl

Fri 6/3

2:35 p.m.-10:55 a.m.

1 stop12h 20m

London Gatwick

Sun 29/3

3:40 p.m.-9:10 p.m.

1 stop13h 30m

C$ 707

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 1/10

1:30 p.m.-9:50 a.m.

1 stop12h 20m

London Heathrow

Thu 30/10

6:20 a.m.-12:25 p.m.

1 stop13h 05m

C$ 711

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sat 4/10

8:30 a.m.-7:15 a.m.

2 stops38h 45m

London Heathrow

Tue 21/10

2:10 p.m.-2:16 p.m.

1 stop32h 06m

C$ 714

SeattleLondon

SEA - LGW

SEALGW

Seattle/Tacoma Intl

Wed 1/10

7:00 p.m.-2:40 p.m.

1 stop11h 40m

London Gatwick

Tue 4/11

11:55 a.m.-5:00 p.m.

1 stop13h 05m

C$ 717

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sat 27/9

4:35 p.m.-7:40 a.m.

1 stop31h 05m

London Heathrow

Fri 10/10

10:50 a.m.-4:59 p.m.

1 stop14h 09m

C$ 717

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 11/3

6:31 a.m.-7:55 a.m.

1 stop18h 24m

London Heathrow

Wed 18/3

6:50 a.m.-10:29 p.m.

2 stops22h 39m

C$ 721

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 14/10

1:30 p.m.-6:50 a.m.

Nonstop9h 20m

London Heathrow

Mon 20/10

9:50 a.m.-11:35 a.m.

Nonstop9h 45m

C$ 781

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sat 4/10

8:20 p.m.-1:40 p.m.

Nonstop9h 20m

London Heathrow

Thu 16/10

9:50 a.m.-11:35 a.m.

Nonstop9h 45m

C$ 785

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to London from

How to get the cheapest flight ticket from Seattle to London

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the typical price of a round-trip flight between Seattle and London?

What is the cheapest month to fly to London?

In general, October is the cheapest month to fly from Seattle to London. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around C$ 915. If you aren’t able to travel to London during the month of October, then flying in January is also cheap. Prices for this month can be found on momondo for an average of C$ 933.

What is the cheapest day to depart on your flight to London?

According to our data, Sunday is the cheapest day to fly to London from Seattle. The lowest ticket price found for a Sunday departure recently was C$ 1,202. Keep in mind that prices can always vary depending on your route and whether or not you are flying domestic or international. When flying out on a Friday, the most expensive travel day of the week, you can expect to see flight prices from Seattle to London for around C$ 1,301.

What is the cheapest time of day to depart on your flight to London?

Our most recent data shows that the best time of day to fly to London is in the morning. Flights from Seattle to London during this time can be as low as C$ 946. In the afternoon is when there is more demand to fly to London, so prices are often more expensive at around C$ 1,298 per ticket.

What is the cheapest Seattle/Tacoma Intl to London flight route?

Fly from Seattle/Tacoma Intl to London Heathrow for the best Seattle/Tacoma Intl - London flight prices

How far in advance should I book a flight to London?

You are more likely to see cheaper flights to London from Seattle when booking weeks ahead of your departure date. In general, you can expect to find flights to London for around C$ 1,113 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to London from Seattle for as low as C$ 979 on momondo.

What cabin class options are available on Seattle/Tacoma Intl to London flights?

There are 4 cabin classes available to choose from on Seattle/Tacoma Intl to London flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Can stopping save me money on Seattle to London flights?

You could potentially save up to 7% on your flight if you consider stops on a Seattle to London flight.

How have Seattle to London flight prices changed over time?

As of September 2025, prices for Seattle to London flights are approximately 43% cheaper when compared to flights at the same time last year.

When to book flights from Seattle to London

Are you open to changing your travel dates? Check out the ideal times to fly from Seattle to London according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Seattle to London (SEA to LON) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Seattle to London

Best price found

C$ 466

Fastest flight time

9h 20m

Direct flights

Every day

Airports in London

1 airport
The best one-way flight to London from Seattle in the past 72 hours is C$ 466. The best round-trip flight deal from Seattle to London found on momondo in the last 72 hours is C$ 930.
The fastest flight from Seattle to London takes 9h 20m
Direct flights go from Seattle to London every day.
There is 1 airport near London: London Heathrow (LHR)
Search flight deals

  • How far is Seattle/Tacoma Intl to London by plane?

    The straight-line distance from Seattle/Tacoma Intl to London is 7694.7 km. 9h 20m is a normal flight duration for this route.

  • When did momondo last update prices for flights from Seattle/Tacoma Intl Airport to London?

    Prices for flights from Seattle/Tacoma Intl Airport to London are updated daily.

  • How many operators does momondo search for flights from Seattle/Tacoma Intl Airport to London?

  • How old do you have to be to fly from Seattle/Tacoma Intl Airport to London?

    Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Seattle/Tacoma Intl Airport to London.

  • What documentation or ID do you need to fly to London?

    The travel and health documents you'll need for your trip to London may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at London. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

  • What is the most popular plane model from Seattle to London?

  • What is the most popular airline from Seattle to London?

Best airlines flying from Seattle to London

Compare and see reviews for airlines that fly from Seattle to London with momondo
Airline
Rating
Free Cancellation
Price
IcelandairPriceFrom C$ 576Free CancellationRating
7.0
546 reviews
Search Icelandair flights
Virgin AtlanticPriceFrom C$ 699Free CancellationRating
7.4
664 reviews
Search Virgin Atlantic flights
British AirwaysPriceFrom C$ 702Free CancellationRating
6.6
7,361 reviews
Search British Airways flights
IberiaPriceFrom C$ 725Free CancellationRating
7.0
2,928 reviews
Search Iberia flights

  • Virgin Atlantic Flights From Seattle to London

    The lowest priced Virgin Atlantic flight from Seattle to London from the last 72 hours was C$ 505. Generally, Virgin Atlantic has 14 flights on this route every week with an average price of C$ 712. Virgin Atlantic is rated 7.4/10 by our users.

  • Iberia Flights From Seattle to London

    C$ 524 is the best Iberia flight deal from Seattle to London found on momondo over the last 72 hours. The average Iberia ticket price found was closer to C$ 621, however, with flight time and availability significantly affecting the price. Iberia (7.0/10 from 2,928 user reviews) flies into London from Seattle 14 times in an average week so prices can vary.

Travelling to a place near London?

Book flights to London if you plan to visit one of these locations
Hounslow
Ipswich
Gatwick
Dartford
Crawley
Ilford
Wembley
Maidstone
Chelmsford
Wokingham
Slough
Canterbury
Feltham
Hayes
Uxbridge
Waterlooville
Newport
Basingstoke
Milton Keynes
Dover

Why use momondo?

Why should I use momondo to find a flight deal from Seattle to London?

momondo collates all your flight options in one place and lets you filter them to find the perfect flight from Seattle to London. momondo saves you time and could save you money on your trip.

Can I find flights from Seattle to London with flexible booking policies on momondo?

Flights from Seattle to London with flexible booking policies can be found by using the search form above and then selecting our dedicated flexible booking filter, which will highlight only the flights where this policy is applied.

How can momondo help me find flights from Seattle to London?

momondo helps you find the best flight between Seattle and London by providing filters to narrow your choice of flights to those matching your criteria. You can select flights based on numerous factors such as price, departure and landing times, airport and airline.

I’m not ready to book a flight from Seattle to London right now. Can momondo alert me if prices change?

Yes. momondo can track prices for Seattle to London flights and alert you when they change. Perform a search to set up the price alert. All that is required is a valid email address.

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Find better results for your trip to the United Kingdom

Fly into one of these airports located in London

Airports listed have a maximum distance of 57.3 km from London
London City Airport
London Gatwick Airport
London Heathrow Airport
London Luton Airport
London Southend Airport
London Stansted Airport