Cheap flights from London Heathrow Airport to Philadelphia from £348

If you aren’t able to travel during the month of March, then book flights to Philadelphia from London Heathrow Airport during January instead. Flights to Philadelphia in January, while not as cheap as those in March, still average around £582.

Our data shows that Tuesday is the least expensive day to fly to Philadelphia. Tickets to fly out on this day can be as low as £649. On the other hand, Sunday is the most expensive day to depart from London Heathrow Airport because it is more convenient for both business and leisure travellers. As a result, prices tend to be around £704.

The cheapest time of day to fly to Philadelphia is in the morning when flights can be purchased for as low as £679. At midday is when there is more demand to fly to Philadelphia, so prices are often more expensive at around £682 per ticket.

Fly from London Heathrow to Philadelphia for the best London Heathrow - Philadelphia flight prices

You are more likely to see cheaper flights to Philadelphia from London Heathrow Airport when booking weeks ahead of your departure date. In general, you can expect to find flights to Philadelphia for around £673 when searching weeks before you fly. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Philadelphia from London Heathrow Airport for as low as £573 on momondo.

There are 4 cabin classes available to choose from on London Heathrow Airport to Philadelphia 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 27% on your flight if you consider stops on a London Heathrow Airport to Philadelphia flight.

As of September 2026, prices for London Heathrow Airport to Philadelphia flights are approximately 20% cheaper when compared to flights at the same time last year.

British Airways, JetBlue, and Lufthansa are the most popular carriers operating from London Heathrow to Philadelphia

Virgin Atlantic, British Airways and Lufthansa are the top three most popular airlines that fly to Philadelphia from London Heathrow Airport according to our data. Virgin Atlantic is the first choice among our users, with 44% of people opting to fly with this airline when travelling to Philadelphia. Keep in mind that there are 21 different airlines that fly to Philadelphia on a routine basis, so you have a few additional options to choose from.

Historically, on average around 16% of flights between London and Philadelphia have experienced a delay on any given week. The average delay length over the past 12 months has been 156 minutes.

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

Saturday 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, American Airlines have had the fewest delays on this route over the last 12 months, with about 13% of their flights experiencing any sort of delay.

Dublin (DUB) was the most common stop: 64% of momondo users choosing one-stop flights on this route connected there.

Flights via Boston (BOS) offer the lowest average return price of £949.

Flights connecting via Boston (BOS) have the shortest average one-way travel time: 14h 04m.

Dublin (DUB) has the shortest average stopover time for this route: 3h 43m.

The number of flights available between London Heathrow Airport and Philadelphia is 14 per day as of September 2026. The most frequent departure time is 13:00, with 58% of daily flights leaving in the afternoon.

102 flights are operational weekly from London Heathrow Airport to Philadelphia as of September 2026. The most popular departure day for this route is Mon, with 15% of flights per week taking off on this day.