PWM - LON

$558 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 11/21. 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

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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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

Fri, Oct 3 - Fri, Oct 10
JetBlue Logo
2:17 pm - 9:30 amPWM-LHR
14h 13m1 stop
JetBlue Logo
11:55 am - 1:22 pmLHR-PWM
30h 27m1 stop
$691JetBlue
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Fri, Sep 12 - Sun, Sep 21
JetBlue Logo
2:17 pm - 9:30 amPWM-LHR
14h 13m1 stop
JetBlue Logo
8:15 am - 10:07 pmLHR-PWM
18h 52m1 stop
$701JetBlue
Find Deal
Tue, Jan 6 - Mon, Jan 12
 Logo
6:00 am - 8:35 pmPWM-LHR
33h 35m2 stops
 Logo
2:50 pm - 4:48 pmLHR-PWM
30h 58m2 stops
Mon, Sep 15 - Mon, Sep 22
JetBlue Logo
7:09 am - 9:30 amPWM-LHR
21h 21m1 stop
JetBlue Logo
8:15 am - 10:07 pmLHR-PWM
18h 52m1 stop
$732JetBlue
Find Deal
Wed, Sep 10 - Wed, Sep 17
United Airlines Logo
2:14 pm - 6:55 amPWM-LHR
11h 41m1 stop
United Airlines Logo
1:30 pm - 11:03 pmLHR-PWM
14h 33m2 stops
$739United Airlines
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Wed, Sep 10 - Wed, Sep 17
American Airlines Logo
2:30 pm - 10:20 amPWM-LHR
14h 50m1 stop
American Airlines Logo
10:05 am - 6:11 pmLHR-PWM
13h 06m1 stop
$751American Airlines
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Tue, Sep 9 - Sun, Sep 21
United Airlines Logo
10:05 am - 6:55 amPWM-LHR
15h 50m1 stop
United Airlines Logo
6:30 am - 6:26 pmLHR-PWM
16h 56m2 stops
$789United Airlines
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Fri, Oct 3 - Fri, Oct 10
Delta Logo
1:35 pm - 1:30 pmPWM-LHR
18h 55m1 stop
Delta Logo
6:15 am - 12:05 amLHR-PWM
22h 50m2 stops
$803Delta
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Mon, Sep 15 - Mon, Sep 22
 Logo
2:14 pm - 9:20 amPWM-LHR
14h 06m2 stops
 Logo
12:40 pm - 1:22 pmLHR-PWM
29h 42m2 stops
Tue, Nov 25 - Sun, Nov 30
Delta Logo
2:35 pm - 6:20 amPWM-LHR
10h 45m1 stop
Delta Logo
8:50 am - 11:51 pmLHR-PWM
20h 01m1 stop
$876Delta
Find Deal
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?

What is the cheapest month to fly from Portland to London?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Portland to London, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Portland to London is October, where tickets cost $677 (return) on average. On the other hand, the most expensive months are July and June, where the average cost of round-trip tickets is $1,188 and $1,174 respectively.

Good to know

Low seasonFebruary
Cheapest flight$558
Best time to beat the crowds with an average 12% 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 $558 for a one-way ticket and $691 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, SkyTeam, and oneworld 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 $793 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 $932 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 7982 reviews
8.5Crew
7.9Entertainment
7.9Comfort
7.3Food
8.2Boarding
Airline reviews

Three seats in first class were broken and while they were able to still acommodate us it was looking very touch and go and they had others they could not acommodate

6.0 GoodKristopher, Aug 2025HPN - ATL
Read more Delta reviews

Three seats in first class were broken and while they were able to still acommodate us it was looking very touch and go and they had others they could not acommodate

Mechanic delay in addition to a 2 hour change in takeoff time was frustrating.

Delayed due to thunderstorms and no in-flight service due to rough weather — both of which are out of Delta’s control. Flight was good overall.

The flight attendants in SLC were rude. I arrived 40 minutes early to gate. Ticket said I needed check in for seat assignments and tried check in and attendants said they weren’t doing it. And proceeded to never call me to give me a ticket so when time to board I received the very last seat. Please relay to employees to do their job better..,

On this flight I felt the food offering was not as complete as on previous flights. The tomato salad was a bit off and there was nothing additional such a bread or butter. The breakfast was only one option, so you either ate what they had or ate nothing. The crew was efficient, but most seemed frustrated throughout the flight. The flight arrived early and was obstacle-free, so I’m overall quite happy, but the shine in the rest of the experience just wasn’t there.

The seats got pretty uncomfortable pretty fast. The armrests are bigger than on other planes, so I had less room in the actual seat. My butt hurt by the end of the flight. :/ comfort was the primary issue. The crew were fantastic!

I believe that a four-hour trip should have a meal. Delta had none.

Great flight with Delta! Boarding was quick and easy, the amenities were solid, and the plane was in great shape. The flight attendants had a fun, lively energy while staying professional. All in all, a smooth trip — even managed to catch up on some rest. Thanks, Delta!

I was uncomfortably cold on the plane. Other than that it was uneventful and therefore as enjoyable as a plane ride can be.

There was supposed to be a meal served, but there wasn’t and the major toilet was out of order

I understand stuff happens, but plane failures are likely due to lack of maintenance. Additionally, air conditioning wasn't working, no snack/drink service, no WiFi. Fortunately, the crew was communicative and light-hearted. United grabbed another plane and we were able to get to our destination.

There was no food available for this red eye... one little waffle cookie for a 6+ hour flight... thank God I was able to sleep some

It is clear that someone knew, and competent, is in charge of food at United Airlines at least for the international flights. I was flying in coach, but the choices of the dinner were excellent. Tasty, and appropriate size. I had the beef, which was a little bit like a shepherds pie, and it was good. Nothing comparable has been served on a United flight in years. It will not be confused with three star food, but it is very good for airline food. Even better was the breakfast choice between a cinnamon roll and a breakfast sandwich. I chose the breakfast sandwich which was absolutely delicious and which I would happily order again at my local Starbucks or Panera. It is clear that someone knew indifferent is in charge of the food and it’s about time.

The flight was comfortable with the exit row and great service

Had to cancel first flight because Airporter Bus took over 3 hrs to get to airport which resulted in an extra $378 dollar fare . Is there anyway I can be reimbursed for initial fare since it was not my fault? Sent from my iPhone EJ Ledet

Plane was crowded and even when we hit altitude, the plane was hot, not enough air flow.

Flight attendant in first class gave poor service (like he didn't want to be there) and food was awful. We sat waiting for gate upon arrival over 45 mins.

The pilots were late and it made us 1 hour late. The meat was tough and bok choy was also tough.

Flight was delayed 3 hours. No food and drink vouchers was provided. They offered a mini pretzel bag and water .

Stuck on tarmac for two hours plus a 5.5 hour flight. Rude flight attendant. And no meals, not even for purchase!

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

Flight was full, and would have preferred an aisle seat, but due to getting a late ticket ,the seat I had was adequate. The flight crew were very help full and hard working. Food and drink were excellent for the 11hr flight. Overall I was pleased with flight, and would recommend British Airways again.

More choices on menu. Seemed only thing offered was Scottish, and while that’s good for the Scot’s it doesn’t help the Americans who don’t like that food. And I really hate it when, during sleep time the attendants have a very loud conversation right over you. Lastly, I paid 5000 dollars for business class, and having to pay more to choose my seat early is really an insult. Seems greedy

The chicken adobo was a little too spicy but good otherwise. My personal opinion. Movie selection could be improved, too many horror movies. Could add a few more chick flicks! The flight was bumpy at times. We arrived a little early too! Flight attendants friendly.

Again flight was awesome except British Airways lost both gate checked luggage’s. Still missing

really bad they refused to check in luggages that I had purchased, even showing them the transaction receipt from british airways app the staff in miami was MEDIOCRE

Crew was great and responsive. Entertainment quit working with about 4 hours remaining on the flight. My seat cushion was broken.

Not very good , the stewardess were unfriendly and they don't like to be bothered. Cos was a night flight and they need to sleep.

British Airways staff are very polite and willing to help.

Worst flight experience ever flights canceled. JetBlue told us just did not even bother standing in line to come back in one and a half hours then without any information we had to go pick up all of our luggage and spend over $2000 in accommodation just to get home. JetBlue said that the next flight available for us to get home would be three days later. Absolutely absurd hasn’t offered to give us any compensation do not fly JetBlue horrible company. They said it was based on the weather and the weather is great in all locations that we would’ve been flying to total hoax. I think it’s a conspiracy theory.

The captain gave good announcements and the flight attendants were friendly. The WiFi was pretty good. The plane itself looked very old inside and the seats were very uncomfortable. The screens in the seat backs were the smallest I’ve ever seen. There were so many loud and obnoxious kids on this flight and the parents didn’t do much to try to quiet them down. Some had videos and games on tablets with higher than necessary volume going the whole time.

Too many long delays with JetBlue. Worst major airline that serves JFK but unfortunately I keep going back because of the prices.

My JetBlue experience was nice. The flights ran on time, the aircraft was clean and comfortable, and the flight attendants were attentive. My only issue, which is isolated to the low-cost (budget) option at JetBlue, is that the check in process makes the user feel that they have to buy their seats. The seats offered for purchase are upgrades from the budget seats you get (which are essentially the last seats remaining). The interface should not make it feel like you must purchase a seat.

The plane was late to leave.. Internet was lousy. TV was not working. when we arrived, We stayed on the plane for a long time before we got to the gate. It took us a long time to retrieve our luggage because they didn’t know what carousel to send them to. It was a bad experience.

I especially liked the lead crew officer. His boarding and safety announcements were made with a bit of novelty and humor. The flight also left the gate 10 minutes early and we landed about 20 minutes early… It was a delightful flight…

There were mutliple delays. There was inconsistent, delayed, and poor communication regarding the delays.

flight was delayed for hours with no explanation. The plane was a very old aircraft.

Spend hours delayed with no food, water anything sitting on the aieplane with no ability to eat or use the restroom. My entire experience was the absolute worst. I will never fly jet Blue again.

It would have been nice if they had offered more than one set of snacks

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

Information on your arrival and departure airports

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