PWM - LON

$220 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 5/12. 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
Travelers love KAYAK
41,299,237 searches in the past 7 days on KAYAK

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Everything you should know

Cheapest round-trip
$633
Typical prices: $860-$1,118
United Airlines
Wed 3/11Wed 3/18
PWM - LHR • 1 stop
Cheapest one-way
$220
United Airlines
Tue 5/12
PWM - LHR • 1 stop
Top airlines
United Airlines
Cheapest • from $633 (round-trip)
Delta
Best reviews • 7.9 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
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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

Wed, Mar 11 - Wed, Mar 18
United Airlines Logo
7:07 pm - 10:25 am
PWM
-
LHR
11h 18m
1 stop
United Airlines Logo
6:50 am - 6:25 pm
LHR
-
PWM
15h 35m
2 stops
$633United Airlines
Wed, Mar 11 - Wed, Mar 18
United Airlines Logo
3:44 pm - 10:50 am
PWM
-
LHR
15h 06m
2 stops
United Airlines Logo
6:50 am - 6:25 pm
LHR
-
PWM
15h 35m
2 stops
$637United Airlines
Wed, May 13 - Tue, May 19
United Airlines Logo
6:00 am - 9:35 pm
PWM
-
LHR
10h 35m
1 stop
United Airlines Logo
6:50 am - 6:23 pm
LHR
-
PWM
16h 33m
2 stops
$649United Airlines
Wed, May 13 - Tue, May 19
United Airlines Logo
11:08 am - 6:55 am
PWM
-
LHR
14h 47m
2 stops
United Airlines Logo
6:50 am - 6:23 pm
LHR
-
PWM
16h 33m
2 stops
$653United Airlines
Wed, May 6 - Mon, May 11
United Airlines Logo
6:00 am - 9:35 pm
PWM
-
LHR
10h 35m
1 stop
United Airlines Logo
5:50 pm - 6:23 pm
LHR
-
PWM
29h 33m
2 stops
$661United Airlines
Wed, Apr 15 - Wed, Apr 22
Scandinavian Airlines Logo
12:46 pm - 7:10 am
PWM
-
LHR
13h 24m
1 stop
Scandinavian Airlines Logo
1:25 pm - 11:23 pm
LHR
-
PWM
14h 58m
1 stop
$676Scandinavian Airlines
Wed, Apr 1 - Wed, Apr 8
Multiple Airlines Logo
5:40 pm - 11:15 am
PWM
-
LHR
12h 35m
1 stop
Multiple Airlines Logo
3:15 pm - 11:27 pm
LHR
-
PWM
13h 12m
1 stop
$678Multiple Airlines
Wed, Apr 15 - Wed, Apr 22
Delta Logo
2:51 pm - 6:20 am
PWM
-
LHR
10h 29m
1 stop
Delta Logo
10:45 am - 11:24 pm
LHR
-
PWM
17h 39m
2 stops
$682Delta
Tue, May 5 - Tue, May 12
Delta Logo
4:42 pm - 4:00 pm
PWM
-
LGW
18h 18m
2 stops
Delta Logo
10:35 am - 12:34 am
LGW
-
PWM
18h 59m
2 stops
$724Delta
Mon, May 4 - Mon, May 11
Multiple Airlines Logo
9:47 am - 10:00 am
PWM
-
LGW
19h 13m
1 stop
Multiple Airlines Logo
2:00 pm - 4:16 pm
LGW
-
PWM
55h 16m
2 stops
$856Multiple 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 March.

Good to know

Low seasonOctober
Cheapest flight$220
Best time to beat the crowds with an average 29% drop in price.
Most popular time to fly and prices are also 10% 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 $220 for a one-way ticket and $633 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?

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

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

    The two airlines most popular with KAYAK users for flights from Portland to London are Delta and United Airlines. With an average price for the route of $753 and an overall rating of 7.9, Delta is the most popular choice. United Airlines is also a great choice for the route, with an average price of $753 and an overall rating of 7.4.

  • 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 4 airlines serving 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.
7.9
DeltaOverall score based on 8203 reviews
8.5Crew
7.9Comfort
7.8Entertainment
7.2Food
8.1Boarding
Airline reviews

Flight was delayed and no reasons provided. After the passengers were boarded, the crew made announcement that the captain has jot arrived and he would take another 15 mins. All passengers patiently sat until the captain came and started. Terrible experience!

2.0 MediocreMansoor, Feb 2026
DTW - RIC
Read more Delta reviews

Flight was delayed and no reasons provided. After the passengers were boarded, the crew made announcement that the captain has jot arrived and he would take another 15 mins. All passengers patiently sat until the captain came and started. Terrible experience!

Flight was delayed. No information on why it was delayed. After we boarded the flight, , the crew made announcement that the captain hs not arrived and he will take 15 mins more to arrive. Passengers were just sitting patiently for the captain to arrive and start, Terrible experience.

Totally worth the miles to upgrade to Delta Comfort. Plenty of legroom.

This was my first time flying Delta ever and I had a great experience!

Smallest leg room I've ever had on a plane.

They took all carry-on luggage from Groups 6 -9 - I was group 5 and waiting in line to board - they made me check my luggage too. That then went to baggage claim and delayed departure from the airport. There was overhead room in my seating area - Delta over reacted. Also, had a gentleman next to me that took up 1/2 my seat.

Excellent!!! Aeromexico is a great airline. What was not that good is the service provided by Kayak. It is never clear and not easy to manage.

Flight delay was frustrating, also you cannot checkin online without delta app, web browser check-in throw errors

The gate agent was most helpful in getting me on to fly standby. I greatly appreciate it.

bulkhead seat had very little legroom - even in bsiness class.

Both the WIFI and entertainment did not work for 2.5h

The crew made our experience extremely bad. They were rude and didn’t have anything for kids.

Very old flight - time to retire it for newer airplanes

2+ hours delayed Outlet in row 12 did not work Tv monitors did not work Lights kept off the entire flight for at 5pm-7pm flight

Very disappointing given gate agent behavior. Filed a formal complaint with United.

Do not like the size of the overhead bin. I think staff should monitor the size of suitcases that are being carried on by passengers to ensure they meet the size requirement.

Crew was great (professional, attentive, prompt). Snacks for 4 hrs flight is deplorable.

Flight delayed. WiFi connectivity very poor if not existant. Last minute arrival forced me to run to catch my connection.

Both of my flights arrived early and check in process was smooth

Terrible. No customer service, no food, no drinks on a 6 hour premier economy booking.

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

Pathetic check in experience at JFK. Everything is self check in. Not enough staff present to help with when the check in process or the kiosk gets stuck. Staff present not welcoming or pleasant at all. On the other hand the NY based flight crew was great. Courteous and friendly throughout the flight. Special meals leave a lot to be desired. Kids meals should be made available when kids are flying and same goes for special kids meals too.

The plane was probably full boarding was easy. We were able to check our carry-on luggage for free. It was a return flight through Philly to LA. Never saw a stewardess do a demonstration of emergency Procedures. I think my flight was pretty full

My flight got delayed and eventually canceled, then rescheduled. I and several others had a connection from Boston to Paris and asked several times if we would make it. They assured us we would and then rebooked us mid flight without our consent and closed doors early even though they said they communicated we were a bit delayed. We got stranded in Boston and I opted with being rebooked for a different connection to France since they refused to pay for a Hotel. I've now been in Europe for 5 days and still haven't recieved my bags. There was absolutely no urgency for the fact that I'm in a foreign country with absolutely no change of clothes or any of my medication. Such an overwhelming and frustrating experience.

Automated scanning was slow and somewhat haphazard. Too many people were unfamiliar with the tech and were forced to learn on the fly. The hands off approach of the gate staff made it more uncomfortable. This needs work. Overall the flight and cabin crew were excellent.

The crew for the flight was A+ top notch. They were friendly and professional and made the flight a very relaxing and enjoable.

Rude crew member. She seemed annoyed at me without me saying a single word. Also loudly admonished me for having my bag next to my seat instead of tucked away before landing. Just telling me to put it away and guiding me without giving me a lecture would have been enough.

No included food for a 5 hour flight and the entertainment was only accessible if you had wired headphones (not provided). Otherwise though, great and smooth flying and customer service.

Crew were fantastic and so catering and wonderful! Full score for the entire crew!

Because of weather and mechanical issues our flight was 4 hours late. The only compensation offered to us was a meal voucher to be used only at Boston Airport and only on the day issued. But by the time it was offered to us all the restaurants were closed, so there was no way to use that offer.

Friendly crew, efficient boarding and flight arrived early. Couldn’t ask for a better experience

Terrible. They canceled our early morning flight after midnight on the day of and had no available flights to rebook my family on for the next 72 hours. Yet they still had other flights that were not cancelled from JFK so it couldn’t be based on the weather. It felt like they canceled the flight based on it not being profitable enough for them. I am not interested in traveling with the again. The absolute worse customer service and lack of accountability.

Horribly rude check in at airport, worst in 25 years of flying. All over a simple issue they could have googled to resolve.

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

Information on your arrival and departure airports