
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $830 (oojo) |
One-way from | $467 (FlightHub) |
Popular in | June |
Cheapest in | January |
Average price | $975 |
Good round-trip deal | $1,010 or less |
Good one-way deal | $503 or less |
Fly from
Fly to
Route
Depart
Return
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Tue 9/8
6:20 pm-12:10 pm
Nonstop9h 50m
London Heathrow
Wed 9/16
11:45 am-4:35 pm
1 stop12h 50m
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Sun 8/23
9:45 pm-3:35 pm
Nonstop9h 50m
London Heathrow
Tue 9/8
5:45 pm-8:13 pm
Nonstop10h 28m
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Tue 8/18
6:20 pm-12:10 pm
Nonstop9h 50m
London Heathrow
Wed 9/30
11:40 am-2:00 pm
Nonstop10h 20m
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Sun 9/13
9:50 pm-3:35 pm
Nonstop9h 45m
London Heathrow
Sat 9/19
6:30 am-11:47 am
1 stop13h 17m
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Sun 7/26
6:20 pm-12:10 pm
Nonstop9h 50m
London Heathrow
Wed 8/12
5:45 pm-8:03 pm
Nonstop10h 18m
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Sun 8/2
11:15 am-9:15 am
1 stop14h 00m
London Heathrow
Fri 8/14
5:45 pm-8:03 pm
Nonstop10h 18m
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Fri 8/7
6:20 pm-12:10 pm
Nonstop9h 50m
London Heathrow
Mon 8/24
5:35 pm-11:15 am
1 stop25h 40m
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Mon 8/3
3:40 pm-12:25 pm
1 stop12h 45m
London Heathrow
Tue 8/11
7:25 am-4:59 pm
1 stop17h 34m
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Fri 10/16
6:20 pm-12:10 pm
Nonstop9h 50m
London Heathrow
Sun 10/25
6:30 am-12:47 pm
1 stop13h 17m
SeattleLondon
SEA - LHR
SEALHR
Seattle/Tacoma Intl
Mon 7/6
9:50 pm-3:35 pm
Nonstop9h 45m
London Heathrow
Fri 7/17
5:45 pm-8:03 pm
Nonstop10h 18m
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy- | Trust Score*1 star | |
| Price Accuracy2 stars | Trust Score*1 star | |
| Price Accuracy- | Trust Score*3 stars | |
| Price Accuracy2 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy1 star | Trust Score*3 stars |
Booking 82 days in advance of your planned departure date is, on average, the best time to get cheap flights from Seattle to London Heathrow Airport. The general trend is that the closer you book to the departure date, the more expensive your flight will be.
Currently, January is the cheapest month in which you can book a flight from Seattle to London Heathrow Airport (average of $642). Flying from Seattle to London Heathrow Airport in June is currently the most expensive (average of $1,205). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.
Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Seattle to London Heathrow Airport as you normally would.
About 14% of weekly flights between Seattle and London have experienced delays in the past year, with the average delay time being 128 minutes.
Historically, flights departing at night are less likely to be delayed, whereas flights leaving in the evening tend to experience delays more often.
Tuesday tends to have the lowest number of delays on this route, whereas Wednesday has historically faced a higher average of delays compared to other days of the week.
Over the last year, Virgin Atlantic have had the lowest number of delays on this route, with just 6% of flights being delayed.
Reykjavik (KEF) – chosen by Cheapflights users on 79% of 1-stop itineraries from Seattle to London Heathrow Airport on Cheapflights.
Montreal (YUL) is the most affordable 1-stop option, with an average round-trip price of $631.
Flights via Reykjavik (KEF) have the shortest average one-way travel time for 1-stop routes: 12h 21m.
Flights via Reykjavik (KEF) offer the fastest connection on this route, with an average layover time of 1h 50m.
Comfort
Crew
Boarding
Overall
Food
Entertainment
Reviews
Anonymous,May 2026
SEA - KOA
Comfort
Crew
Boarding
Overall
Food
Entertainment
Reviews
Anonymous,May 2026
SEA - KOA
Comfort
Crew
Boarding
Overall
Food
Entertainment
Reviews
Anonymous,May 2026
SEA - KOA
Comfort
Crew
Boarding
Overall
Food
Entertainment
Reviews
Anonymous,May 2026
SEA - KOA
Comfort
Crew
Boarding
Overall
Food
Entertainment
Reviews
Anonymous,May 2026
SEA - KOA
Comfort
Crew
Boarding
Overall
Food
Entertainment
Reviews
Anonymous,May 2026
SEA - KOA
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$481 | Average$628 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$483 | Average$641 | FlexibilityNo cancel fee | On-time76% | |
| Cheapest$515 | Average$792 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$525 | Average$716 | FlexibilityNo cancel fee | On-time70% | |
| Cheapest$532 | Average$764 | FlexibilityNo cancel fee | On-time77% | |
| Cheapest$547 | Average$842 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$549 | Average$863 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$554 | Average$789 | FlexibilityNo cancel fee | On-time77% | |
| Cheapest$556 | Average$694 | FlexibilityNo cancel fee | On-time76% | |
| Cheapest$571 | Average$927 | FlexibilityNo cancel fee | On-time72% |