Cheap flights from London to Philadelphia from £256

If you aren’t able to travel during the month of September, then book flights to Philadelphia from London during May instead. Flights to Philadelphia in May, while not as cheap as those in September, still average around £536.

Our data shows that Wednesday is the least expensive day to fly to Philadelphia. Tickets to fly out on this day can be as low as £610. On the other hand, Sunday is the most expensive day to depart from London because it is more convenient for both business and leisure travellers. As a result, prices tend to be around £678.

The cheapest time of day to fly to Philadelphia is in the morning when flights can be purchased for as low as £629. At midday is when there is more demand to fly to Philadelphia, so prices are often more expensive at around £636 per ticket.

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

You are more likely to see cheaper flights to Philadelphia from London when booking weeks ahead of your departure date. In general, you can expect to find flights to Philadelphia for around £578 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 for as low as £522 on momondo.

There are 3 cabin classes available to choose from on London to Philadelphia flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

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

Virgin Atlantic, British Airways and Lufthansa are the top three most popular airlines that fly to Philadelphia from London according to our data. Virgin Atlantic is the first choice among our users, with 47% of people opting to fly with this airline when travelling to Philadelphia. Keep in mind that there are 23 different airlines that fly to Philadelphia on a routine basis, so you have a few additional options to choose from.

Historically, on average around 17% 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 176 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.

Wednesday is statistically the day of the week that experiences the fewest delays on this flight route. Sunday 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 16% of their flights experiencing any sort of delay.

Dublin (DUB) was the most common stop: 63% of momondo users choosing one-stop flights on this route connected there.

Flights via Boston (BOS) offer the lowest average return price of £512.

Flights connecting via Montreal (YUL) have the shortest average one-way travel time: 10h 06m.

Montreal (YUL) has the shortest average stopover time for this route: 1h 26m.

14 flights are operational daily from London to Philadelphia as of April 2026. The most popular departure time for this route is 13:00, with 75% of flights per day taking off in the afternoon.

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