Cheap flights from London to Philadelphia from $364

The cheapest month to fly to Philadelphia from London is in September. Flight prices, which tend to average around $670, are often lower during this time because this is during the off-season. The month of May is another great option to travel to Philadelphia, with average flight prices from London averaging around $712.

The cheapest day to depart from London to Philadelphia is on a Thursday. Travelers who choose to depart for Philadelphia on a Thursday will often find tickets for as low as $781. On the other hand, Sunday is the most expensive day to depart from London because it is more convenient for both business and leisure travelers. As a result, prices tend to be around $956.

According to our data, the cheapest time of day to fly to Philadelphia is at noon. momondo users have found flights departing from London to Philadelphia at noon for as low as $791. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. In contrast, the most expensive time of day to depart to Philadelphia is in the morning when prices are around $830.

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 $768 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Philadelphia from London for as low as $694 on momondo.

There are 4 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.

You could potentially save up to 6% on your flight if you consider stops on a London to Philadelphia flight.

As of March 2026, prices for London to Philadelphia flights are approximately 4% more expensive when compared to flights at the same time last year.

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

British Airways, American Airlines and Virgin Atlantic are the top three most popular airlines that fly to Philadelphia from London according to our data. British Airways is the first choice among our users, with 56% of people opting to fly with this airline when traveling to Philadelphia. Keep in mind that there are 18 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 179 minutes.

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

Wednesday is statistically the day of the week which experiences the fewest number of 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 least number of 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: 50% of momondo users choosing 1-stop flights on this route connected there.

Flights via Boston (BOS) offer the lowest average round-trip price of $589.

Flights connecting via Dublin (DUB) have the shortest average one-way travel time: 12h 10m.

Dublin (DUB) has the shortest average layover time for this route: 2h 10m.

The number of flights available between London and Philadelphia is 10 per day as of March 2026. The most frequent departure time is 10:00AM, with 50% of daily flights leaving at noon.

The number of flights available between London and Philadelphia is 70 per week as of March 2026. The most frequent departure day is Mon, with 14% of weekly flights leaving on this day.