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Cheap flights from Seattle to London from C$ 334

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 1/10. 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

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
mar., 9 sep. - mar., 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
mié., 1 oct. - vie., 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
mié., 3 sep. - vie., 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
lun., 8 sep. - vie., 19 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
dom., 7 sep. - mié., 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
mar., 14 oct. - mié., 22 oct.
Icelandair Logo
3:45 p.m. - 11:45 a.m.SEA-LGW
12h 00m1 stop
Icelandair Logo
3:40 p.m. - 5:50 p.m.LGW-SEA
34h 10m1 stop
C$ 705Icelandair
Find Deal
lun., 18 ago. - mar., 26 ago.
SWISS Logo
4:25 p.m. - 5:50 p.m.SEA-LGW
17h 25m1 stop
SWISS Logo
6:35 p.m. - 6:36 p.m.LGW-SEA
32h 01m2 stops
C$ 706SWISS
Find Deal
lun., 8 sep. - mar., 16 sep.
Icelandair Logo
3:45 p.m. - 11:45 a.m.SEA-LGW
12h 00m1 stop
Icelandair Logo
3:40 p.m. - 5:50 p.m.LGW-SEA
34h 10m1 stop
C$ 708Icelandair
Find Deal
lun., 18 ago. - dom., 31 ago.
SWISS Logo
4:25 p.m. - 5:50 p.m.SEA-LGW
17h 25m1 stop
SWISS Logo
6:35 p.m. - 6:36 p.m.LGW-SEA
32h 01m2 stops
C$ 709SWISS
Find Deal
lun., 11 ago. - lun., 18 ago.

United Airlines flights from Seattle to London

Our best United Airlines deals on Seattle to London 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

Our best British Airways deals on Seattle to London 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 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 julio 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

mar. 9/9

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

1 stop12h 20m

London Heathrow

mar. 16/9

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

1 stop12h 25m

C$ 663

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

mié. 1/10

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

Nonstop9h 20m

London Heathrow

vie. 31/10

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

Nonstop10h 05m

C$ 683

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

mié. 3/9

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

1 stop12h 44m

London Heathrow

vie. 12/9

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

1 stop17h 34m

C$ 688

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

lun. 8/9

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

1 stop18h 20m

London Heathrow

vie. 19/9

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

1 stop14h 09m

C$ 690

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

dom. 7/9

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

Nonstop9h 50m

London Heathrow

mié. 1/10

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

1 stop13h 00m

C$ 699

SeattleLondon

SEA - LHR

SEALHR

Seattle/Tacoma Intl

mar. 14/10

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

Nonstop9h 45m

London Heathrow

mié. 22/10

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

1 stop13h 20m

C$ 701

SeattleLondon

SEA - LGW

SEALGW

Seattle/Tacoma Intl

lun. 18/8

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

1 stop12h 00m

London Gatwick

mar. 26/8

3:40 p.m.-5:50 p.m.

1 stop34h 10m

C$ 705

SeattleLondon

SEA - LGW

SEALGW

Seattle/Tacoma Intl

lun. 8/9

4:25 p.m.-5:50 p.m.

1 stop17h 25m

London Gatwick

mar. 16/9

6:35 p.m.-6:36 p.m.

2 stops32h 01m

C$ 706

SeattleLondon

SEA - LGW

SEALGW

Seattle/Tacoma Intl

lun. 18/8

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

1 stop12h 00m

London Gatwick

dom. 31/8

3:40 p.m.-5:50 p.m.

1 stop34h 10m

C$ 708

SeattleLondon

SEA - LGW

SEALGW

Seattle/Tacoma Intl

lun. 11/8

4:25 p.m.-5:50 p.m.

1 stop17h 25m

London Gatwick

lun. 18/8

6:35 p.m.-6:36 p.m.

2 stops32h 01m

C$ 709

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 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$ 916. 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$ 930.

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$ 1,218. 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 for around C$ 1,311.

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$ 943. In the afternoon is when there is more demand to fly to London, so prices are often more expensive at around C$ 1,301 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$ 1,110 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$ 974 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 59% 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 July 2025, prices for Seattle to London flights are approximately 57% 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$ 334

Fastest flight time

9h 20m

Direct flights

Every day

Airports in London

2 airports
The best one-way flight to London from Seattle in the past 72 hours is C$ 334. The best round-trip flight deal from Seattle to London found on momondo in the last 72 hours is C$ 663.
The fastest flight from Seattle to London takes 9h 20m
Direct flights go from Seattle to London every day.
There are 2 airports near London: London Heathrow (LHR), London Gatwick (LGW)
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$ 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

    The lowest priced Virgin Atlantic flight from Seattle to London from the last 72 hours was C$ 573. Generally, Virgin Atlantic has 14 flights on this route every week with an average price of C$ 722. 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$ 630, however, with flight time and availability significantly affecting the price. Iberia (7.0/10 from 2,859 user reviews) flies into London from Seattle 13 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
Ipswich
Hounslow
Gatwick
Dartford
Canterbury
Crawley
Ilford
Wembley
Maidstone
Chelmsford
Wokingham
Feltham
Uxbridge
Waterlooville
Newport
Basingstoke
Milton Keynes
Dover
Worthing
Guildford

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