PWM - LON

$256 Find Cheap Flights from Portland to London

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Portland to London departing on 5/7. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

KAYAK searches hundreds of travel sites at once for deals on flights to London

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Portland to London, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Portland to London, as well as popular online travel agencies
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41.299.237 searches in the past 7 days on KAYAK

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Everything you should know

Cheapest round-trip
$725
Delta
vie. 5/8mié. 5/13
PWM - LHR • 1 stop
Cheapest one-way
$256
KLM
jue. 5/7
PWM - LHR • 1 stop
Top airlines
Cheapest • from $725 (round-trip)
Best reviews • 7.4 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
Nonstop flights
Not available
There are currently no direct flights between Portland and London. You'll need at least 1 connection.
Insights
Insights
Insights
Insights
Top layover airports
Cheapest • Avg $725 (round-trip)
Shortest trip • 9h 52m (one-way)
Insights
Insights
Insights
Insights
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KAYAK searches 100s of sites at once to find you the best travel deals.
We hope you love your trip to London!
Flight Deals
Booking Insights
Flight Deals

Cheap Flights from Portland to London (PWM-LON)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Portland to London that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Portland to London

vie., may. 8 - mié., may. 13
Delta Logo
2:38 pm - 6:20 am
PWM
-
LHR
10h 42m
1 stop
Delta Logo
8:40 am - 12:43 am
LHR
-
PWM
21h 03m
2 stops
$725Delta
sáb., may. 2 - sáb., may. 9
Delta Logo
4:43 pm - 1:15 pm
PWM
-
LHR
15h 32m
2 stops
Delta Logo
8:40 am - 11:09 pm
LHR
-
PWM
19h 29m
2 stops
$729Delta
jue., may. 7 - dom., may. 10
Delta Logo
4:48 pm - 12:10 pm
PWM
-
LHR
14h 22m
2 stops
Delta Logo
11:45 am - 12:43 am
LHR
-
PWM
17h 58m
2 stops
$730Delta
sáb., may. 2 - sáb., may. 9
KLM Logo
2:51 pm - 10:20 am
PWM
-
LHR
14h 29m
1 stop
KLM Logo
11:15 am - 11:09 pm
LHR
-
PWM
16h 54m
1 stop
$731KLM
jue., may. 7 - jue., may. 14
Delta Logo
2:38 pm - 12:10 pm
PWM
-
LHR
16h 32m
1 stop
Delta Logo
9:55 am - 12:43 am
LHR
-
PWM
19h 48m
2 stops
$741Delta
jue., may. 7 - dom., may. 10
Virgin Atlantic Logo
6:00 am - 6:25 am
PWM
-
LHR
19h 25m
1 stop
Virgin Atlantic Logo
1:25 pm - 11:09 pm
LHR
-
PWM
14h 44m
1 stop
$747Virgin Atlantic
jue., may. 7 - dom., may. 10
Virgin Atlantic Logo
6:00 am - 6:25 am
PWM
-
LHR
19h 25m
1 stop
Virgin Atlantic Logo
1:25 pm - 11:09 pm
LHR
-
PWM
14h 44m
1 stop
$748Virgin Atlantic
sáb., may. 2 - sáb., may. 9
Multiple Airlines Logo
7:30 am - 9:55 am
PWM
-
LGW
45h 25m
2 stops
Multiple Airlines Logo
7:10 am - 11:03 pm
LGW
-
PWM
20h 53m
2 stops
$839Multiple Airlines
sáb., may. 2 - sáb., may. 9
Multiple Airlines Logo
7:30 am - 10:25 pm
PWM
-
LGW
33h 55m
2 stops
Multiple Airlines Logo
7:10 am - 11:03 pm
LGW
-
PWM
20h 53m
2 stops
$928Multiple Airlines
mié., may. 6 - lun., may. 11
Turkish Airlines Logo
7:20 am - 9:55 am
PWM
-
LGW
21h 35m
2 stops
Turkish Airlines Logo
5:35 pm - 11:03 pm
LGW
-
PWM
34h 28m
2 stops
$962Turkish Airlines
Booking Insights

KAYAK's insights & trends for Portland to London flights

Get data-powered insights and trends into flights from Portland to London to help you find the cheapest flights, the best time to fly and much more.

How much is a round-trip flight from Portland, Maine to London?

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from Portland, Maine to London departing in May.

Good to know

Low seasonOctober
Cheapest flight$256
Best time to beat the crowds with an average 31% drop in price.
Most popular time to fly and prices are also 14% lower on average.
Flight from Portland to London Heathrow Airport

When to book flights from Portland to London

Are your dates flexible? Find out the best times to travel from Portland to London based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking flights from Portland to London

  • What is the cheapest flight from Portland to London?

    In the last 3 days, the lowest price for a flight from Portland to London was $256 for a one-way ticket and $725 for a round-trip.

  • Do I need a passport to fly between Portland and London?

    Yes

  • Which aircraft models fly most regularly from Portland to London?

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

  • Which airline alliances offer flights from Portland to London?

    Star Alliance is the only airline alliance operating flights between Portland and London.

  • Which is the best airline for flights from Portland to London, United Airlines or American Airlines?

    The two airlines most popular with KAYAK users for flights from Portland to London are United Airlines and American Airlines. With an average price for the route of $714 and an overall rating of 7.4, United Airlines is the most popular choice. American Airlines is also a great choice for the route, with an average price of $1,047 and an overall rating of 7.1.

  • How does KAYAK find such low prices on flights from Portland to London?

    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 Portland to London.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Portland to London?

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

  • What is the Hacker Fare option on flights from Portland to London?

    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 London with an airline and back to Portland with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Portland to London?

    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 London from Portland up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top airlines flying from Portland to London

 
See real verified KAYAK customer reviews for airlines flying from Portland to London. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Portland to London? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
7.4
United AirlinesOverall score based on 9554 reviews
7.7Boarding
7.1Entertainment
7.3Comfort
8.1Crew
6.6Food
Airline reviews

Poor communication, flight was delayed for preventable reasons. I missed my connection.

2.0 MediocreAaron, Apr 2026
ORD - BNA
Read more United Airlines reviews

Poor communication, flight was delayed for preventable reasons. I missed my connection.

It was better than excellent. The staff in Mason City were great. The young woman that pushed my wheelchair did more than could be expected of her. She came from India 17 years ago. I don't remember her name.

After arriving in Chicago, we were taxiing for 1.5 hours with infrequent and untruthful updates about the amount of time it would take to arrive at the gate. Minimally, the team could have provided timing expectations that were more truthful, especially one their original expectations were not met.

All good flight was 35 minutes early when arriving in Edinburgh

Flights were on time actually early service was good and crew cheerful

Every staff member was professional, friendly and courteous. The pizza twist was ok. It was warm but too much dough.

The boarding timing needs to be improved. The flight was delayed again because it took way too long to board. I was already exhausted from sleeping at the airport and spending all day there due to delay from my previous flight that connected in Chicago.

I had a terrible experience. My flight got delayed from Atlanta to Chicago on Monday April 6, 2026, and that led to me missing my next flight to Brussels. United Airlines didn’t provide me with any accommodation for shelter. I had to sleep at the airport in Chicago. The next flight I was put on didn’t leave until the evening hours of Tuesday 4/7/2026.

Boarding was again a "free for all". We were boarding group 4, and almost the entire plane was able to board before us. It's a shame that someone who follows the rules, gets the short end of the stick. Not fair.

Flight left on time, arrived early, pleasant staff provided water, coffee, etc. access to bathrooms was reasonable and were well maintained. blankets were available, lots of entertainment options. LUGGAGE SERVICE WAS GREAT. I got my one checked bag quickly and was able to make a bus connection for a 2 hour bus ride saving me from waiting another 1.5 hours.

We did not have enough time to make our connecting flight. As a result, we were put onto a different airline for our second leg. The different airline was NOT comparable to British Airlines, and our arrival was significantly delayed. The actual flight on BA was amazing.

Tv screens and movie selection v good. Friendly staff. They were really worried about max capacity and room for carryons. That is never fun but i had no problem finding space when I boarded.

My flight to London from Philadelphia was cancelled due to weather.

Disliked having to wait a little longer to disembark from the plan when we landed in London

Food should be better quality. Video screens have poor resolution and the library of movies is poor. The other airlines are much better.

The trip was smooth but the crew were very abrupt, snatching things before finished and being quite snappy when asked questions.

My wife and I love to travel, so we fly a lot. We've already logged 381,075 miles and with practically every major airline. But this flight was very disappointing. It started off well, with no delays and a new plane. But when lunchtime approached, all that good impression was ruined. Instead of white tablecloths, we were offered small, dark placemats, which, as it turned out, were perfectly adequate for the food. All the food offered—and my wife and I only took fish, and the meat—was not just bad, it was downright disgusting and not heated enough. The same applies to the appetizers. This was the first time in many years of traveling that we've been offered such disgusting food.

Lost luggage stuck no clothes and no word after 2 days leaving on cruise no stuff or clothes

Don’t know they cancelled the flight day before I was to leave. They sent a email at 9:00 pm at night saying they cancelled. That is the smooth way to say we don’t want your business! I think they didn’t have enough people booking so they cancelled the flight! It’s all about the money anymore there is no honesty in business.

The flight was canceled 3 hours after original take off time

Everything you need to know for your flight from Portland to London

Information on your arrival and departure airports