Cheap flights from Philadelphia to London from $221

The cheapest month to fly to London from Philadelphia is in September. Flight prices, which tend to average around $646, are often lower during this time because this is during the off-season. The month of November is another great option to travel to London, with average flight prices from Philadelphia averaging around $664.

The cheapest day to depart from Philadelphia to London is on a Wednesday. Travelers who choose to depart for London on a Wednesday will often find tickets for as low as $769. If your travel schedule is flexible, try to avoid departing on a Saturday because tickets tend to average around $995. These prices are subject to change though, so be sure to set up a Price Alert for flights to London.

Flying to London from Philadelphia in the afternoon is the least expensive time of day to depart. momondo users have found prices as low as $834 when looking at flights departing in the afternoon. Flights to London are more costly in the evening, with an average ticket price of $881. Departure times in the evening fall within the peak daily travel times, which is why tickets can be more expensive.

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

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

There are 4 cabin classes available to choose from on Philadelphia to London 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 7% on your flight if you consider stops on a Philadelphia to London flight.

As of March 2026, prices for Philadelphia to London flights are approximately 7% cheaper when compared to flights at the same time last year.

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

British Airways, United Airlines and American Airlines are the top three most popular airlines that fly to London 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. Keep in mind that there are 22 different airlines that fly to London on a routine basis, so you have a few additional options to choose from.

Boston (BOS) was the most common stop: 67% of momondo users choosing 1-stop flights on this route connected there.

Flights via Boston (BOS) offer the lowest average round-trip price of $1.

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, 10 flights take off from Philadelphia and land in London 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, 70 flights take off from Philadelphia and land in London each week. The most common flight departure day for this route is Mon, with 14% of weekly flights taking off on this day.