Cheap flights from Philadelphia to London from $273

The month of September is, on average, the cheapest month to fly to London Heathrow Airport from Philadelphia, with most prices found around $655. If you’re not able to fly to London Heathrow Airport in September, then October is your next best option. Flight prices from Philadelphia to London Heathrow Airport during October average around $669.

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 $768. The most expensive day to fly to London Heathrow Airport is Saturday, with ticket prices averaging around $995.

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 Philadelphia to London Heathrow Airport in the afternoon for as low as $834. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. Flights in the evening are often more expensive with an average ticket price of $881.

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

You are more likely to see cheaper flights to London Heathrow Airport from Philadelphia when booking weeks ahead of your departure date. In general, you can expect to find flights to London Heathrow Airport for around $828 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 Philadelphia for as low as $690 on momondo.

There are 4 cabin classes available to choose from on Philadelphia to London Heathrow 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 5% on your flight if you consider stops on a Philadelphia to London Heathrow Airport flight.

As of March 2026, prices for Philadelphia to London Heathrow Airport flights are approximately 15% cheaper when compared to flights at the same time last year.

TAP AIR PORTUGAL, Delta, and British Airways are the most popular carriers operating from Philadelphia to London Heathrow

British Airways, United Airlines and American Airlines are the top three most popular airlines that fly to London Heathrow Airport from Philadelphia according to our data. British Airways is the first choice among our users, with 50% 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.

Boston (BOS) was the most common stop: 80% of momondo users choosing 1-stop flights on this route connected there.

Flights via Dublin (DUB) offer the lowest average round-trip price of $678.

Flights connecting via Dublin (DUB) have the shortest average one-way travel time: 9h 35m.

Frankfurt am Main (FRA) has the shortest average layover time for this route: 1h 18m.

As of March 2026, 2 flights take off from Philadelphia and land in London Heathrow Airport each day. The most common flight departure time for this route is 6:00PM, with 100% of daily flights taking off in the evening.

As of March 2026, there are 20 flights per week flying from Philadelphia to London Heathrow Airport. The most common day of the week flights depart is Fri, with 50% of flights taking off on this day.