Cheap flights from San Francisco to London from $450

The month of February is, on average, the cheapest month to fly to London Heathrow Airport from San Francisco, with most prices found around $648. If you’re not able to fly to London Heathrow Airport in February, then October is your next best option. Flight prices from San Francisco to London Heathrow Airport during October average around $667.

Our data shows that Wednesday is the least expensive day to fly to London Heathrow Airport. Tickets to fly out on this day can be as low as $826. The most expensive day to fly to London Heathrow Airport is Saturday, with ticket prices averaging around $959.

According to our data, the cheapest time of day to fly to London Heathrow Airport is in the afternoon. momondo users have found flights departing from San Francisco to London Heathrow Airport in the afternoon for as low as $867. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. Flights at noon are often more expensive with an average ticket price of $924.

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

You are more likely to see cheaper flights to London Heathrow Airport from San Francisco when booking weeks ahead of your departure date. In general, you can expect to find flights to London Heathrow Airport for around $783 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to London Heathrow Airport from San Francisco for as low as $755 on momondo.

You could potentially save up to 39% on your flight if you consider stops on a San Francisco to London Heathrow Airport flight.

As of May 2026, prices for San Francisco to London Heathrow Airport flights are approximately 5% more expensive when compared to flights at the same time last year.

KLM and United Airlines are the most popular carriers operating from San Francisco to London Heathrow

United Airlines, British Airways and Virgin Atlantic are the top three most popular airlines that fly to London Heathrow Airport from San Francisco according to our data. United Airlines is the first choice among our users, with 42% of people opting to fly with this airline when traveling to London Heathrow Airport. Keep in mind that there are 21 different airlines that fly to London Heathrow Airport 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 160 minutes.

Generally, flights departing at night tend to experience fewer delays. Flights in the early afternoon have, in the past, seen delays more frequently in comparison.

Monday is statistically the day of the week which experiences the fewest number of 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 least number of delays on this route over the last 12 months; with about 8% of their flights experiencing any sort of delay.

Dublin (DUB) was the most common stop: 27% of momondo users choosing 1-stop flights on this route connected there.

Flights via Lisbon (LIS) offer the lowest average round-trip price of $524.

Flights connecting via Dublin (DUB) have the shortest average one-way travel time: 13h 39m.

Frankfurt am Main (FRA) has the shortest average layover time for this route: 1h 28m.

The number of flights available between San Francisco and London Heathrow Airport is 42 per day as of May 2026. The most frequent departure time is 4:00PM, with 59% of daily flights leaving in the afternoon.

As of May 2026, 294 flights take off from San Francisco and land in London Heathrow Airport each week. The most common flight departure day for this route is Mon, with 14% of weekly flights taking off on this day.