Cheap flights from London to San Francisco from $541 LCY, LGW, LHR, LTN, STN → SFO
London City Airport (LCY), London Gatwick Airport (LGW), London Heathrow Airport (LHR), London Luton Airport (LTN), Stansted Airport (STN) → San Francisco International Airport (SFO)
The cheapest return found recently is $586 with Alaska Airlines, 10 Dec – 8 Jan 2027, found 2 days ago. The cheapest one-way found recently is $541 with Lufthansa, 14 Oct 2027, found 6 days ago.
- Cheapest one-way found recently
- $541, found 6 days ago
- Cheapest return found recently
- $586, 10 Dec to 8 Jan 2027
- Usual return price
- $717 to $830
- Cheapest month to fly
- December 2026, return fares from $586 found in the last 7 days
- Airlines with nonstop flights
- Air France, Virgin Atlantic
Return
The cheapest return fare on each of 5 departure dates is usually $717 to $830.
Cheapest return found recently
$586
10 Dec – 8 Jan 2027 · Alaska Airlines
London Heathrow Airport (LHR) → San Francisco International Airport (SFO)
Leaves 2:45 p.m. · Return leaves 10:40 a.m. · 32 h 43 min of travel, both ways together
out 1 stop, back 1 stop
found 2 days ago
Cheapest nonstop return
$1,773
4 Jan 2027 – 26 Jan 2027 · KLM
London Heathrow Airport (LHR) → San Francisco International Airport (SFO)
Leaves 11:50 a.m. · Return leaves 2:55 a.m. · 21 h 15 min of travel, both ways together
out nonstop, back nonstop
found 3 days ago
Found recently, and the cheapest we hold
$586 10 Dec – 8 Jan 2027found 2 days agoSee 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 11 Nov, the cheapest return we saw each day was $484 to $737.
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 10 Dec to 1 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 29-night return fares leaving within 3 days of 10 Dec to compare.
Every date we hold
37 fares on 5 departure dates
See the chart as a table
| Dates | From | Airline | Airports | Stops | Found | |
|---|---|---|---|---|---|---|
| 10 Dec – 8 Jan 2027 | $586 | Alaska Airlines | London Heathrow Airport (LHR) → San Francisco International Airport (SFO) | out 1 stop, back 1 stop | found 2 days ago | See prices for these dates |
| 11 Dec – 23 Dec | $717 | SWISS | London Heathrow Airport (LHR) → San Francisco International Airport (SFO) | out 1 stop, back 1 stop | found 2 days ago | See prices for these dates |
| 21 Dec – 18 Jan 2027 | $830 | Aer Lingus | London Heathrow Airport (LHR) → San Francisco International Airport (SFO) | out 1 stop, back 1 stop | found 3 days ago | See prices for these dates |
| 4 Jan 2027 – 27 Jan 2027 | $1,031 | Iberia | London Luton Airport (LTN) → San Francisco International Airport (SFO) | out 3 stops, back 1 stop | found 3 days ago | See prices for these dates |
| 1 Apr 2027 – 16 Apr 2027 | $741 | Lufthansa | London Heathrow Airport (LHR) → San Francisco International Airport (SFO) | out 1 stop, back 1 stop | found 5 days ago | See prices for these dates |
Which month looks cheapest?
December 2026 is the cheapest month — from $586.
Airlines on the cheapest dates: Alaska Airlines, SWISS, Aer Lingus, Iberia, Lufthansa.
One-way
Not enough comparable prices yet for a usual one-way price.
Cheapest one-way found recently
$541
14 Oct 2027 · Lufthansa
London Heathrow Airport (LHR) → San Francisco International Airport (SFO)
Leaves 10:50 a.m. · 15 h 35 min trip
1 stop
found 6 days ago
Cheapest nonstop one-way
None seen yet.
Found recently, and the cheapest we hold
$541 14 Oct 2027found 6 days agoOpen this trip
It is also the cheapest one-way we hold, of any age.
What have prices looked like?
Over 24 days, 29 Sept to 8 Nov, the cheapest one-way we saw each day was $485 to $930.
24 days is a short history, so treat this range as an early guide.
Those were the prices on those days, not today's.
Is this a good one-way price?
Not enough comparable prices yet: we hold one-way fares on 1 departure date and need at least 3 to say what is usual.
Could nearby dates be cheaper?
We hold no other one-way fares leaving within 3 days of 14 Oct 2027 to compare.
Every date we hold
5 fares on 1 departure dates
See every date as a table
| Dates | From | Airline | Airports | Stops | Found | |
|---|---|---|---|---|---|---|
| 14 Oct 2027 | $541 | Lufthansa | London Heathrow Airport (LHR) → San Francisco International Airport (SFO) | 1 stop | found 6 days ago | Open this trip |
Airlines on the cheapest dates: Lufthansa.
Premium cabin fares from London to San Francisco
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 10 Dec – 8 Jan 2027 in another cabin: Premium economy · Business · First
Today's prices for 14 Oct 2027 in another cabin: Premium economy · Business · First
How far ahead were prices cheapest for London to San Francisco?
Return
The cheapest fares were 7 to 13 days before departure.
From the cheapest return each day between 24 Sept and 11 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 | $588 | $531 | +4% | 19 |
| 7–13 days | $565 | $498 | Cheapest seen | 32 |
| 14–29 days | $636 | $490 | +13% | 23 |
| 30–59 days | $692 | $495 | +23% | 41 |
| 60–89 days | $573 | $527 | +1% | 19 |
| 90–179 days | $612 | $484 | +8% | 35 |
| 180+ days | $675 | $573 | +20% | 19 |
One-way
Not enough history yet: in 24 days of one-way prices, 29 Sept to 8 Nov, fewer than 3 booking ranges had prices on 7 days or more.
Live price for these dates
The cheapest return found recently is for 10 Dec – 8 Jan 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 San Francisco?
The cheapest return found recently is $586 with Alaska Airlines, 10 Dec to 8 Jan 2027, found 2 days ago. The cheapest return fare on each of 5 departure dates is usually $717 to $830.
How much is a one-way flight from London to San Francisco?
The cheapest one-way found recently is $541 with Lufthansa, 14 Oct 2027, found 6 days ago.
What is the cheapest month to fly from London to San Francisco?
December 2026 is the cheapest month for a return, from $586, 10 Dec to 8 Jan 2027, found 2 days ago.
How far ahead should I book a flight from London to San Francisco?
In 49 days of prices between 24 Sept and 11 Nov, return fares were cheapest 7 to 13 days before departure.
Is there a direct flight from London to San Francisco?
Yes, the cheapest nonstop return found recently is $1,773 with KLM, 4 Jan 2027 to 26 Jan 2027, found 3 days ago.
How long is the flight from London to San Francisco?
The cheapest one-way found recently, with Lufthansa on 14 Oct 2027, takes 15 h 35 min with 1 stop.
Which airlines have the cheapest flights from London to San Francisco?
Between 10 Dec and 1 Apr 2027, Alaska Airlines has the cheapest return on 1 of the 5 departure dates we hold, SWISS on 1 and Aer Lingus 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