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Cheap flights from Seattle to London from C$ 410

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 4/11. 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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Cheap round-trip flights

Aer Lingus Logo
7:35 p.m. - 3:55 p.m.SEA-LHR
12h 20m1 stop
Aer Lingus Logo
1:25 p.m. - 5:50 p.m.LHR-SEA
12h 25m1 stop
C$ 663Aer Lingus
Find Deal
Tue, 9 Sep - Tue, 16 Sep
British Airways Logo
8:20 p.m. - 1:40 p.m.SEA-LHR
9h 20mdirect
British Airways Logo
9:25 a.m. - 12:30 p.m.LHR-SEA
10h 05mdirect
C$ 683British Airways
Find Deal
Wed, 1 Oct - Fri, 31 Oct
United Airlines Logo
3:36 p.m. - 12:20 p.m.SEA-LHR
12h 44m1 stop
United Airlines Logo
7:25 a.m. - 4:59 p.m.LHR-SEA
17h 34m1 stop
C$ 688United Airlines
Find Deal
Wed, 3 Sep - Fri, 12 Sep
United Airlines Logo
7:15 a.m. - 9:35 a.m.SEA-LHR
18h 20m1 stop
United Airlines Logo
10:50 a.m. - 4:59 p.m.LHR-SEA
14h 09m1 stop
C$ 690United Airlines
Find Deal
Mon, 8 Sep - Fri, 19 Sep
United Airlines Logo
7:20 a.m. - 6:30 a.m.SEA-LHR
15h 10m1 stop
United Airlines Logo
10:50 a.m. - 4:59 p.m.LHR-SEA
14h 09m1 stop
C$ 691United Airlines
Find Deal
Tue, 19 Aug - Wed, 3 Sep
Delta Logo
8:25 p.m. - 2:15 p.m.SEA-LHR
9h 50mdirect
Delta Logo
6:15 a.m. - 11:15 a.m.LHR-SEA
13h 00m1 stop
C$ 699Delta
Find Deal
Sun, 7 Sep - Wed, 1 Oct
Delta Logo
5:35 p.m. - 11:20 a.m.SEA-LHR
9h 45mdirect
Delta Logo
6:30 a.m. - 11:50 a.m.LHR-SEA
13h 20m1 stop
C$ 701Delta
Find Deal
Tue, 14 Oct - Wed, 22 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$ 712British Airways
Find Deal
Wed, 3 Sep - Wed, 1 Oct
Icelandair Logo
3:45 p.m. - 11:55 a.m.SEA-LHR
12h 10m1 stop
Icelandair Logo
1:05 p.m. - 8:40 p.m.LHR-SEA
15h 35m1 stop
C$ 719Icelandair
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Sun, 5 Oct - Sun, 12 Oct
Icelandair Logo
2:35 p.m. - 10:50 a.m.SEA-LHR
12h 15m1 stop
Icelandair Logo
12:15 p.m. - 5:00 p.m.LHR-SEA
12h 45m1 stop
C$ 720Icelandair
Find Deal
Fri, 28 Nov - Fri, 5 Dec

United Airlines flights from Seattle to London Heathrow Airport

Our best United Airlines deals on Seattle to London Heathrow Airport flight tickets
United Airlines
3 Sep
SEA3:36 p.m.Seattle/Tacoma Intl
12h 44m
1 stop
LHR12:20 p.m.London Heathrow
12 Sep
LHR7:25 a.m.London Heathrow
17h 34m
1 stop
SEA4:59 p.m.Seattle/Tacoma Intl
C$ 688
Find similar
United Airlines
8 Sep
SEA7:15 a.m.Seattle/Tacoma Intl
18h 20m
1 stop
LHR9:35 a.m.London Heathrow
19 Sep
LHR10:50 a.m.London Heathrow
14h 09m
1 stop
SEA4:59 p.m.Seattle/Tacoma Intl
C$ 690
Find similar
United Airlines
19 Aug
SEA7:20 a.m.Seattle/Tacoma Intl
15h 10m
1 stop
LHR6:30 a.m.London Heathrow
3 Sep
LHR10:50 a.m.London Heathrow
14h 09m
1 stop
SEA4:59 p.m.Seattle/Tacoma Intl
C$ 691
Find similar

British Airways flights from Seattle to London Heathrow Airport

Our best British Airways deals on Seattle to London Heathrow Airport flight tickets
British Airways
1 Oct
SEA8:20 p.m.Seattle/Tacoma Intl
9h 20m
LHR1:40 p.m.London Heathrow
31 Oct
LHR9:25 a.m.London Heathrow
10h 05m
SEA12:30 p.m.Seattle/Tacoma Intl
C$ 683
Find similar
British Airways
3 Sep
SEA8:20 p.m.Seattle/Tacoma Intl
9h 20m
LHR1:40 p.m.London Heathrow
1 Oct
LHR9:50 a.m.London Heathrow
9h 45m
SEA11:35 a.m.Seattle/Tacoma Intl
C$ 712
Find similar
British Airways
7 Sep
SEA8:20 p.m.Seattle/Tacoma Intl
9h 20m
LHR1:40 p.m.London Heathrow
22 Sep
LHR9:50 a.m.London Heathrow
9h 45m
SEA11:35 a.m.Seattle/Tacoma Intl
C$ 753
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from Seattle to London Heathrow Airport 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 31 July 2025.
Use the filters below to find and compare flights from Seattle to London Heathrow Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 9/9

7:35 p.m.-3:55 p.m.

1 stop12h 20m

London Heathrow

Tue 16/9

1:25 p.m.-5:50 p.m.

1 stop12h 25m

C$ 663

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 1/10

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

Nonstop9h 20m

London Heathrow

Fri 31/10

9:25 a.m.-12:30 p.m.

Nonstop10h 05m

C$ 683

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 3/9

3:36 p.m.-12:20 p.m.

1 stop12h 44m

London Heathrow

Fri 12/9

7:25 a.m.-4:59 p.m.

1 stop17h 34m

C$ 688

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Mon 8/9

7:15 a.m.-9:35 a.m.

1 stop18h 20m

London Heathrow

Fri 19/9

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

1 stop14h 09m

C$ 690

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 19/8

7:20 a.m.-6:30 a.m.

1 stop15h 10m

London Heathrow

Wed 3/9

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

1 stop14h 09m

C$ 691

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 7/9

8:25 p.m.-2:15 p.m.

Nonstop9h 50m

London Heathrow

Wed 1/10

6:15 a.m.-11:15 a.m.

1 stop13h 00m

C$ 699

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Tue 14/10

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

Nonstop9h 45m

London Heathrow

Wed 22/10

6:30 a.m.-11:50 a.m.

1 stop13h 20m

C$ 701

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Wed 3/9

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

Nonstop9h 20m

London Heathrow

Wed 1/10

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

Nonstop9h 45m

C$ 712

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Sun 5/10

3:45 p.m.-11:55 a.m.

1 stop12h 10m

London Heathrow

Sun 12/10

1:05 p.m.-8:40 p.m.

1 stop15h 35m

C$ 719

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

Fri 28/11

2:35 p.m.-10:50 a.m.

1 stop12h 15m

London Heathrow

Fri 5/12

12:15 p.m.-5:00 p.m.

1 stop12h 45m

C$ 720

Flights are sorted by cheapest round-trip flights first.

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See travel insights to London from

How to get the cheapest flight ticket from Seattle to London Heathrow Airport

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 cheapest month to fly to London Heathrow Airport?

The month of March is, on average, the cheapest month to fly to London Heathrow Airport from Seattle, with most prices found around C$ 943. If you aren’t able to travel to London Heathrow Airport during the month of March, then flying in April is also cheap. Prices for this month can be found on momondo for an average of C$ 961.

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

According to our data, Sunday is the cheapest day to fly to London Heathrow Airport from Seattle. The lowest ticket price found for a Sunday departure recently was C$ 1,218. 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 Heathrow Airport for around C$ 1,311.

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

Our data shows that the cheapest Seattle to London Heathrow Airport flights are usually those with departure times in the morning. Our users have found flights to London Heathrow Airport in the morning for as low as C$ 938. In the afternoon is when there is more demand to fly to London Heathrow Airport, so prices are often more expensive at around C$ 1,301 per ticket.

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

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

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

You are more likely to see cheaper flights to London Heathrow Airport from Seattle when booking weeks ahead of your departure date. In general, you can expect to find flights to London Heathrow Airport for around C$ 1,110 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to London Heathrow Airport from Seattle for as low as C$ 974 on momondo.

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

There are 4 cabin classes available to choose from on Seattle/Tacoma Intl to London Heathrow 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 Heathrow Airport flights?

You could potentially save up to 59% on your flight if you consider stops on a Seattle to London Heathrow Airport flight.

How have Seattle to London Heathrow Airport flight prices changed over time?

As of July 2025, prices for Seattle to London Heathrow Airport flights are approximately 45% cheaper when compared to flights at the same time last year.

When to book flights from Seattle to London Heathrow Airport

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

Cheap Seattle to London Heathrow Airport (SEA to LHR) flight deals and tips

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

Best price found

C$ 410

Fastest flight time

9h 20m

Direct flights

Every day
The best one-way flight to London Heathrow Airport from Seattle in the past 72 hours is C$ 410. The best round-trip flight deal from Seattle to London Heathrow Airport found on momondo in the last 72 hours is C$ 663.
The fastest flight from Seattle to London Heathrow Airport takes 9h 20m
Direct flights go from Seattle to London Heathrow Airport every day.
Search flight deals

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

    London Heathrow is 7683.2 km away from Seattle/Tacoma Intl. A reasonable flight in good conditions will take 9h 20m.

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

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

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

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

    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 Heathrow Airport.

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

    The travel and health documents you'll need for your trip to London Heathrow Airport 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 Heathrow Airport. 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 Heathrow Airport?

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

Best airlines flying from Seattle to London Heathrow Airport

Compare and see reviews for airlines that fly from Seattle to London Heathrow Airport with momondo
Airline
Rating
Free Cancellation
Price
IcelandairPriceFrom C$ 574Free CancellationRating
7.0
520 reviews
Search Icelandair flights
IberiaPriceFrom C$ 722Free CancellationRating
7.0
2,859 reviews
Search Iberia flights
Virgin AtlanticPriceFrom C$ 791Free CancellationRating
7.4
655 reviews
Search Virgin Atlantic flights
British AirwaysPriceFrom C$ 823Free CancellationRating
6.6
7,222 reviews
Search British Airways flights

  • Virgin Atlantic Flights From Seattle to London Heathrow Airport

    Virgin Atlantic operates around 14 flights from Seattle to London Heathrow Airport every week. The average price of these flights found in the last 72 hours has been C$ 722, but momondo users have found Virgin Atlantic deals from Seattle to London Heathrow Airport from as low as C$ 573 round-trip. Virgin Atlantic has been scored 7.4/10 in 655 reviews.

  • Iberia Flights From Seattle to London Heathrow Airport

    Another popular option for Seattle to London Heathrow Airport flights is Iberia (7.0/10, 2,859 ratings). Iberia flies from Seattle to London Heathrow Airport around 13 times per week, with deals starting from C$ 524 round-trip and rising to an average price of around C$ 630.

Travelling to a place near London?

Book flights to London if you plan to visit one of these locations
Ipswich
Hounslow
Gatwick
Dartford
Poole
Canterbury
Crawley
Ilford
Wembley
Maidstone
Swindon
Chelmsford
Wokingham
Stratford-upon-Avon
Feltham
Uxbridge
Waterlooville
Newport
Basingstoke
Milton Keynes

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?

All flight searches from Seattle to London on momondo can be filtered to show those which offer flexible booking policies.

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

Once all potential Seattle to London flight options are in front of you, momondo lets you sort and filter flights based on preferences such as airline, price and flight times amongst many other options.

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

Of course. momondo tracks the price of Seattle to London flights. All you need is a valid email address and we will do the rest; it is that quick and easy.

An easier way to manage your London Heathrow Airport trip

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