$753 Find cheap flights from London Heathrow Airport to Portland, Maine

In the last 3 days, the lowest price for a flight from London Heathrow Airport to Portland, Maine was $753 for a one-way ticket and $782 for a round-trip.

Yes, you'll most likely have to show a valid passport before boarding the plane in London and on arrival in Portland.

We unfortunately don’t have that data for this specific route.

oneworld, SkyTeam, and Star Alliance are the airline alliances operating flights between London and Portland, with Star Alliance being the most commonly used for this route.

KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from London to Portland.

KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Portland from London is likely to change within 7 days, so travelers know whether to wait or book now.

Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Portland with an airline and back to London with another airline. Booking your flights between London and PWM can sometimes prove cheaper using this method.

Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Portland from London up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.