How does KAYAK find such low prices on flights from Washington to London Heathrow Airport?

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 Washington to London Heathrow Airport.

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

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

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 Heathrow Airport with an airline and back to Washington with another airline.

What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Washington to London Heathrow Airport?

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

$284 CHEAP FLIGHTS from Washington to London Heathrow (LHR)

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Cheap Flights from Washington to London

Discover the best prices for you by selecting your travel dates on KAYAK.

Round-trip

One-way

Last minute

Direct

Recent round-trip flight deals from Washington to London

Fri, Oct 2 - Sun, Oct 4

3:55 pm - 6:30 pmSEA Seattle/Tacoma Intl-LHR London Heathrow

18h 35m2 stops Kastrup Copenhagen Stockholm Arlanda

5:00 pm - 8:20 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

35h 20m2 stops Kastrup Copenhagen Chicago O'Hare Intl

$652Scandinavian Airlines

Sun, Oct 4 - Sat, Oct 10

3:55 pm - 5:40 pmSEA Seattle/Tacoma Intl-LHR London Heathrow

17h 45m1 stop Kastrup Copenhagen

6:40 am - 1:45 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

15h 05m2 stops Stockholm Arlanda Kastrup Copenhagen

$655Scandinavian Airlines

Mon, Dec 7 - Thu, Dec 24

8:21 am - 8:05 amSEA Seattle/Tacoma Intl-LHR London Heathrow

15h 44m2 stops Toronto Pearson Intl Dublin

12:15 pm - 5:00 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

12h 45m1 stop Reykjavik Keflavik Intl

$655Multiple Airlines

Sun, Dec 6 - Thu, Dec 24

8:21 am - 8:05 amSEA Seattle/Tacoma Intl-LHR London Heathrow

15h 44m2 stops Toronto Pearson Intl Dublin

12:15 pm - 5:00 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

12h 45m1 stop Reykjavik Keflavik Intl

$655Multiple Airlines

Thu, Dec 10 - Thu, Dec 31

2:35 pm - 10:50 amSEA Seattle/Tacoma Intl-LHR London Heathrow

12h 15m1 stop Reykjavik Keflavik Intl

12:15 pm - 5:00 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

12h 45m1 stop Reykjavik Keflavik Intl

$701Icelandair

Sun, Dec 6 - Sun, Dec 13

2:35 pm - 7:30 pmSEA Seattle/Tacoma Intl-LHR London Heathrow

20h 55m1 stop Reykjavik Keflavik Intl

8:35 pm - 5:00 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

28h 25m1 stop Reykjavik Keflavik Intl

$703Icelandair

Mon, Feb 1 - Thu, Feb 4

3:15 pm - 9:20 amSEA Seattle/Tacoma Intl-LHR London Heathrow

34h 05m2 stops Vancouver Intl Calgary

8:45 am - 9:27 amLHR London Heathrow-SEA Seattle/Tacoma Intl

32h 42m2 stops Munich Franz Josef Strauss Vancouver Intl

$722Lufthansa

Wed, Jan 13 - Fri, Jan 15

8:00 am - 5:45 pmSEA Seattle/Tacoma Intl-LHR London Heathrow

25h 45m2 stops Washington, D.C. Dulles Intl Frankfurt am Main

2:30 pm - 2:37 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

32h 07m1 stop Vancouver Intl

$773Lufthansa

Wed, Sep 16 - Fri, Sep 18

9:00 am - 7:25 amSEA Seattle/Tacoma Intl-LHR London Heathrow

14h 25m1 stop San Francisco

6:50 am - 8:18 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

21h 28m2 stops Brussels Bruxelles-National Washington, D.C. Dulles Intl

$786United Airlines

Mon, Oct 5 - Wed, Oct 7

2:10 pm - 2:40 pmSEA Seattle/Tacoma Intl-LHR London Heathrow

16h 30m1 stop Frankfurt am Main

9:00 am - 4:59 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

15h 59m1 stop Munich Franz Josef Strauss

$793United Airlines

Recent last minute flight deals from Washington to London

Thu, Aug 20 - Sun, Aug 23

6:50 pm - 9:20 amSEA Seattle/Tacoma Intl-LHR London Heathrow

30h 30m3 stops Munich Franz Josef Strauss Stockholm Arlanda Warsaw Frederic Chopin

9:05 pm - 10:42 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

33h 37m3 stops Stockholm Arlanda Munich Franz Josef Strauss Vancouver Intl

$826Multiple Airlines

Wed, Aug 19 - Fri, Aug 21

2:10 pm - 12:40 pmSEA Seattle/Tacoma Intl-LHR London Heathrow

14h 30m1 stop Frankfurt am Main

9:00 am - 4:59 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

15h 59m1 stop Munich Franz Josef Strauss

$858Lufthansa

Wed, Aug 19 - Sun, Aug 23

2:10 pm - 9:20 amSEA Seattle/Tacoma Intl-LHR London Heathrow

35h 10m3 stops Frankfurt am Main Stockholm Arlanda Warsaw Frederic Chopin

9:05 pm - 11:55 amLHR London Heathrow-SEA Seattle/Tacoma Intl

22h 50m2 stops Stockholm Arlanda Frankfurt am Main

$861Multiple Airlines

Sun, Aug 23 - Thu, Sep 3

3:55 pm - 4:00 pmSEA Seattle/Tacoma Intl-LHR London Heathrow

16h 05m1 stop Kastrup Copenhagen

5:00 pm - 1:45 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

28h 45m1 stop Kastrup Copenhagen

$872Scandinavian Airlines

Sun, Aug 23 - Fri, Sep 4

3:55 pm - 4:00 pmSEA Seattle/Tacoma Intl-LHR London Heathrow

16h 05m1 stop Kastrup Copenhagen

6:40 am - 1:45 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

15h 05m1 stop Kastrup Copenhagen

$880Scandinavian Airlines

Sun, Aug 23 - Wed, Aug 26

7:20 pm - 1:20 pmSEA Seattle/Tacoma Intl-LHR London Heathrow

34h 00m1 stop Vancouver Intl

6:30 am - 2:22 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

15h 52m2 stops Frankfurt am Main Vancouver Intl

$889Lufthansa

Sun, Aug 23 - Tue, Aug 25

6:20 pm - 12:10 pmSEA Seattle/Tacoma Intl-LHR London Heathrow

9h 50mnonstop

11:45 am - 4:27 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

12h 42m1 stop Amsterdam Schiphol

$917KLM

Wed, Aug 19 - Fri, Aug 21

9:45 pm - 3:35 pmSEA Seattle/Tacoma Intl-LHR London Heathrow

9h 50mnonstop

11:45 am - 4:27 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

12h 42m1 stop Amsterdam Schiphol

$917KLM

Sun, Aug 23 - Wed, Sep 30

7:00 pm - 8:20 pmSEA Seattle/Tacoma Intl-LHR London Heathrow

17h 20m1 stop Reykjavik Keflavik Intl

9:25 pm - 8:40 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

31h 15m1 stop Reykjavik Keflavik Intl

$945Icelandair

Sat, Aug 22 - Mon, Aug 31

11:25 pm - 11:55 amSEA Seattle/Tacoma Intl-LHR London Heathrow

28h 30m1 stop Reykjavik Keflavik Intl

9:25 pm - 11:45 amLHR London Heathrow-SEA Seattle/Tacoma Intl

22h 20m1 stop Reykjavik Keflavik Intl

$948Icelandair

Recent direct flight deals from Washington to London

Tue, Dec 1 - Wed, Dec 9

1:30 pm - 7:00 amSEA Seattle/Tacoma Intl-LHR London Heathrow

9h 30mnonstop

2:55 pm - 4:50 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

9h 55mnonstop

$832British Airways

Sun, Nov 15 - Fri, Nov 27

6:45 pm - 12:10 pmSEA Seattle/Tacoma Intl-LHR London Heathrow

9h 25mnonstop

2:55 pm - 4:50 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

9h 55mnonstop

$832British Airways

Wed, Nov 18 - Sun, Nov 22

6:45 pm - 12:10 pmSEA Seattle/Tacoma Intl-LHR London Heathrow

9h 25mnonstop

2:55 pm - 4:50 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

9h 55mnonstop

$832Multiple Airlines

Mon, Nov 30 - Mon, Dec 7

6:55 pm - 12:20 pmSEA Seattle/Tacoma Intl-LHR London Heathrow

9h 25mnonstop

2:55 pm - 4:50 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

9h 55mnonstop

$832Multiple Airlines

Wed, Feb 10 - Thu, Feb 18

6:55 pm - 12:20 pmSEA Seattle/Tacoma Intl-LHR London Heathrow

9h 25mnonstop

2:45 pm - 4:50 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

10h 05mnonstop

$864Alaska Airlines

Wed, Dec 9 - Thu, Dec 17

6:55 pm - 12:20 pmSEA Seattle/Tacoma Intl-LHR London Heathrow

9h 25mnonstop

2:45 pm - 4:50 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

10h 05mnonstop

$864Alaska Airlines

Mon, Dec 7 - Wed, Dec 23

4:50 pm - 10:40 amSEA Seattle/Tacoma Intl-LHR London Heathrow

9h 50mnonstop

12:20 pm - 2:54 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

10h 34mnonstop

$882KLM

Wed, Dec 9 - Thu, Dec 17

4:50 pm - 10:40 amSEA Seattle/Tacoma Intl-LHR London Heathrow

9h 50mnonstop

12:20 pm - 2:54 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

10h 34mnonstop

$882Air France

Mon, Nov 23 - Tue, Dec 1

4:50 pm - 10:40 amSEA Seattle/Tacoma Intl-LHR London Heathrow

9h 50mnonstop

12:20 pm - 2:54 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

10h 34mnonstop

$914Air France

Tue, Sep 15 - Tue, Sep 22

5:30 pm - 11:20 amSEA Seattle/Tacoma Intl-LHR London Heathrow

9h 50mnonstop

5:45 pm - 8:10 pmLHR London Heathrow-SEA Seattle/Tacoma Intl

10h 25mnonstop

$931KLM

Useful Info

Low season	January
High season	July
Cheapest flight	$284

Best time to beat the crowds with an average 21% drop in price.

Most popular time to fly with an average 29% increase in price.

Flight from Seattle to London Heathrow Airport

MichaelFlew with Delta-May 2026

We like Delta, Alaska and American. Be prepared for a bit of a trek from your arrival gate to Customs and outside services. Heathrow doesn't rank high on my list of major airports.

Verified travelerFlew with American Airlines-Apr 2026

Heathrow is too gigantic to have less than 2 hours of layover time.

Verified travelerFlew with British Airways-Apr 2025

Make sure you have plenty of time between flights if you are delayed.

Verified travelerFlew with British Airways-Feb 2025

Don’t take a flight if you sick, or if you have no choice prepare to stay covered with mask throughout the flight

Verified travelerFlew with British Airways-Apr 2024

Bring a sack lunch -- airport food was very expensive.

How does KAYAK find such low prices on flights from Washington to London Heathrow Airport?
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 Washington to London Heathrow Airport.
How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Washington to London Heathrow Airport?
KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to London Heathrow Airport from Washington 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 Washington to London Heathrow Airport?
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 Heathrow Airport with an airline and back to Washington with another airline.
What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Washington to London Heathrow Airport?
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 Heathrow Airport from Washington up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

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$284 Find Cheap Flights from Washington to London Heathrow Airport - Compare and Save

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