Cheap flights from London to Seattle from $455 LCY, LGW, LHR, LTN, STN → SEA
London City Airport (LCY), London Gatwick Airport (LGW), London Heathrow Airport (LHR), London Luton Airport (LTN), Stansted Airport (STN) → Seattle-Tacoma International Airport (SEA)
The cheapest return found recently is $455 with Icelandair, 22 Apr 2027 – 29 Apr 2027, found today.
- Cheapest return found recently
- $455, 22 Apr 2027 to 29 Apr 2027
- Usual return price
- $457 to $721
- Cheapest month to fly
- April 2027, return fares from $455 found in the last 7 days
Return
The cheapest return fare on each of 5 departure dates is usually $457 to $721.
Cheapest return found recently
$455
22 Apr 2027 – 29 Apr 2027 · Icelandair
London Heathrow Airport (LHR) → Seattle-Tacoma International Airport (SEA)
Leaves 1:05 p.m. · Return leaves 7:00 p.m. · 30 h 10 min of travel, both ways together
out 1 stop, back 1 stop
found today
Cheapest nonstop return
None seen yet.
Found recently, and the cheapest we hold
$455 22 Apr 2027 – 29 Apr 2027found todaySee prices for these dates
It is also the cheapest return we hold, of any age.
What have prices looked like?
Over 49 days, 24 Sept to 12 Nov, the cheapest return we saw each day was $459 to $747.
At $455, the cheapest return found recently is below that range.
Those were the prices on those days, not today's.
Is this a good return price?
Compared with the cheapest return fare on each of 5 departure dates from 5 Dec to 22 Apr 2027, found by travelers' searches in the last 7 days (economy, the price the seller showed on Aviasales). The usual range is the middle half of those prices.
Could nearby dates be cheaper?
We hold no other 7-night return fares leaving within 3 days of 22 Apr 2027 to compare.
Every date we hold
18 fares on 5 departure dates
See the chart as a table
| Dates | From | Airline | Airports | Stops | Found | |
|---|---|---|---|---|---|---|
| 5 Dec – 20 Dec | $721 | Air France | London Heathrow Airport (LHR) → Seattle-Tacoma International Airport (SEA) | out 1 stop, back 1 stop | found 6 days ago | See prices for these dates |
| 20 Jan 2027 – 20 Jan 2027 | $849 | Lufthansa City Airlines | London Heathrow Airport (LHR) → Seattle-Tacoma International Airport (SEA) | out 1 stop, back 1 stop | found 6 days ago | See prices for these dates |
| 15 Feb 2027 – 22 Feb 2027 | $457 | Icelandair | London Heathrow Airport (LHR) → Seattle-Tacoma International Airport (SEA) | out 1 stop, back 1 stop | found 4 days ago | See prices for these dates |
| 20 Apr 2027 – 4 May 2027 | $491 | Icelandair | London Heathrow Airport (LHR) → Seattle-Tacoma International Airport (SEA) | out 1 stop, back 1 stop | found yesterday | See prices for these dates |
| 22 Apr 2027 – 29 Apr 2027 | $455 | Icelandair | London Heathrow Airport (LHR) → Seattle-Tacoma International Airport (SEA) | out 1 stop, back 1 stop | found today | See prices for these dates |
Which month looks cheapest?
April 2027 is the cheapest month — from $455.
Airlines on the cheapest dates: Icelandair, Air France, Lufthansa City Airlines.
Premium cabin fares from London to Seattle
We hold no premium economy, business or first-class fares for this route: we collect them for the busiest routes, and this one is not among them yet.
Today's prices for 22 Apr 2027 – 29 Apr 2027 in another cabin: Premium economy · Business · First
How far ahead were prices cheapest for London to Seattle?
Return
Fares 90 to 179 days before departure were typically 15% lower than 0 to 6 days before departure.
From the cheapest return each day between 24 Sept and 12 Nov (49 days), grouped by how many days ahead the flight left; one adult in economy.
Each range covers different departure dates, so this compares typical fares, not the same trip priced twice.
Prices reflect recent searches — current fares may differ.
See these ranges as a table
| Booked ahead by | Typical fare | Cheapest day | Above the cheapest | Days of prices |
|---|---|---|---|---|
| 0–6 days | $595 | $585 | +18% | 12 |
| 7–13 days | $605 | $585 | +20% | 7 |
| 14–29 days | $591 | $517 | +17% | 13 |
| 60–89 days | $747 | $459 | +48% | 23 |
| 90–179 days | $505 | $464 | Cheapest seen | 34 |
| 180+ days | $785 | $475 | +55% | 22 |
Live price for these dates
The cheapest return found recently is for 22 Apr 2027 – 29 Apr 2027. A live search on this page shows what those dates cost now, for one adult in economy.
Questions about this trip
How much is a return flight from London to Seattle?
The cheapest return found recently is $455 with Icelandair, 22 Apr 2027 to 29 Apr 2027, found today. The cheapest return fare on each of 5 departure dates is usually $457 to $721.
What is the cheapest month to fly from London to Seattle?
April 2027 is the cheapest month for a return, from $455, 22 Apr 2027 to 29 Apr 2027, found today.
How far ahead should I book a flight from London to Seattle?
In 49 days of prices between 24 Sept and 12 Nov, return fares 90 to 179 days before departure were typically 15% lower than 0 to 6 days before departure.
Which airlines have the cheapest flights from London to Seattle?
Between 5 Dec and 22 Apr 2027, Icelandair has the cheapest return on 3 of the 5 departure dates we hold, Air France on 1 and Lufthansa City Airlines on 1.
Prices are what travelers' searches on Aviasales found in the last 7 days, in US dollars: the price the seller showed on Aviasales; bags may cost extra. Fares change, so check today's price before you book. How our prices work