Cheap flights from San Francisco to London from £249

The cheapest month to fly to London from San Francisco is in February. Flight prices, which tend to average around £480, are often lower during this time because this is during the off-season. The month of January is another great option to travel to London, with average flight prices from San Francisco averaging around £505.

Our data shows that Wednesday is the least expensive day to fly to London. Tickets to fly out on this day can be as low as £577. When flying out on a Tuesday, the most expensive travel day of the week, you can expect to see flight prices from San Francisco to London for around £805.

The cheapest time of day to fly to London is in the morning when flights can be purchased for as low as £580. Flights at midday are often more expensive, with an average ticket price of £877.

Fly from San Francisco to London Heathrow for the best San Francisco - London flight prices

You are more likely to see cheaper flights to London from San Francisco when booking weeks ahead of your departure date. In general, you can expect to find flights to London for around £645 when searching weeks before you fly. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to London from San Francisco for as low as £598 on momondo.

There are 4 cabin classes available to choose from on San Francisco to London flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

You could potentially save up to 11% on your flight if you consider stops on a San Francisco to London flight.

As of August 2026, prices for San Francisco to London flights are approximately 45% cheaper when compared to flights at the same time last year.

ITA Airways, JetBlue, and United Airlines are the most popular carriers operating from San Francisco to London

Virgin Atlantic, United Airlines and British Airways are the top three most popular airlines that fly to London from San Francisco according to our data. Virgin Atlantic is the first choice among our users, with 45% of people opting to fly with this airline when travelling to London. Keep in mind that there are 6 different airlines that fly to London on a routine basis, so you have a few additional options to choose from.

Historically, on average around 11% of flights between San Francisco and London have experienced a delay on any given week. The average delay length over the past 12 months has been 151 minutes.

Generally, flights departing in the evening tend to experience fewer delays. Flights departing in the morning have, in the past, seen delays more frequently in comparison.

Monday is statistically the day of the week that experiences the fewest delays on this flight route. Thursday has historically seen more delays on average compared to the rest of the week.

According to our data, British Airways have had the fewest delays on this route over the last 12 months, with about 8% of their flights experiencing any sort of delay.

Copenhagen (CPH) was the most common stop: 67% of momondo users choosing one-stop flights on this route connected there.

Flights via Copenhagen (CPH) offer the lowest average return price of £410.

Flights connecting via Copenhagen (CPH) have the shortest average one-way travel time: 15h 20m.

Copenhagen (CPH) has the shortest average stopover time for this route: 3h 05m.

The number of flights available between San Francisco and London is 38 per day as of August 2026. The most frequent departure time is 16:00, with 66% of daily flights leaving in the afternoon.

As of August 2026, there are 266 flights per week flying from San Francisco to London. The most common day of the week flights depart is Mon, with 14% of flights taking off on this day.