PWM - LON

$336 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 7/4. 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
$759
United Airlines
Wed 11/11Fri 11/13
PWM - LHR • 1 stop
Cheapest one-way
$336
Multiple Airlines
Sat 7/4
PWM - LGW • 1 stop
Top airlines
Cheapest • from $759 (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 $853 (round-trip)
Shortest trip • 9h 58m (one-way)
Insights
Insights
Insights
Insights
When to travel
Cheapest • 100% price drop
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
Start a new search
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

Wed, Nov 11 - Fri, Nov 13
United Airlines Logo
7:22 pm - 10:50 am
PWM
-
LHR
10h 28m
1 stop
United Airlines Logo
6:50 am - 6:13 pm
LHR
-
PWM
16h 23m
2 stops
$759United Airlines
Wed, Nov 11 - Fri, Nov 13
United Airlines Logo
2:45 pm - 9:10 am
PWM
-
LHR
13h 25m
2 stops
United Airlines Logo
6:50 am - 4:09 pm
LHR
-
PWM
14h 19m
2 stops
$828United Airlines
Tue, Nov 10 - Tue, Nov 17
Scandinavian Airlines Logo
2:35 pm - 9:20 am
PWM
-
LHR
13h 45m
2 stops
Scandinavian Airlines Logo
7:30 pm - 11:49 pm
LHR
-
PWM
33h 19m
2 stops
$831Scandinavian Airlines
Sat, Aug 29 - Wed, Sep 9
JetBlue Logo
6:40 am - 8:45 pm
PWM
-
LHR
9h 05m
1 stop
JetBlue Logo
8:15 am - 11:52 pm
LHR
-
PWM
20h 37m
1 stop
$836JetBlue
Wed, Nov 11 - Fri, Nov 13
United Airlines Logo
2:45 pm - 8:25 am
PWM
-
LHR
12h 40m
2 stops
United Airlines Logo
6:50 am - 4:09 pm
LHR
-
PWM
14h 19m
2 stops
$864United Airlines
Tue, Nov 10 - Tue, Nov 17
Delta Logo
6:30 am - 6:20 am
PWM
-
LHR
18h 50m
1 stop
Delta Logo
6:30 am - 10:23 pm
LHR
-
PWM
20h 53m
2 stops
$866Delta
Tue, Nov 10 - Tue, Nov 17
Delta Logo
1:35 pm - 9:00 am
PWM
-
LHR
14h 25m
1 stop
Delta Logo
6:30 am - 11:49 pm
LHR
-
PWM
22h 19m
2 stops
$867Delta
Tue, Nov 10 - Tue, Nov 17
Delta Logo
2:35 pm - 10:15 am
PWM
-
LHR
14h 40m
1 stop
Delta Logo
6:30 am - 10:23 pm
LHR
-
PWM
20h 53m
2 stops
$868Delta
Mon, Nov 2 - Sat, Nov 7
Multiple Airlines Logo
6:00 am - 7:10 am
PWM
-
LHR
20h 10m
2 stops
Multiple Airlines Logo
7:25 am - 11:43 pm
LHR
-
PWM
21h 18m
1 stop
$876Multiple Airlines
Fri, Jul 3 - Fri, Jul 10
Multiple Airlines Logo
9:52 am - 10:00 am
PWM
-
LGW
19h 08m
1 stop
Multiple Airlines Logo
2:00 pm - 9:12 am
LGW
-
PWM
24h 12m
1 stop
$1,043Multiple 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 November.

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 January, where tickets cost $0 (return) on average. On the other hand, the most expensive months are June and November, where the average cost of round-trip tickets is $986 and $850 respectively.

Good to know

Low seasonOctober
Cheapest flight$336
Best time to beat the crowds with an average 29% drop in price.
Most popular time to fly and prices are also 11% lower on average.
Flight from Portland to London Gatwick 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 $336 for a one-way ticket and $759 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 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 $746 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 9737 reviews
7.3Comfort
7.7Boarding
8.1Crew
7.1Entertainment
6.6Food
Airline reviews

Our flight was canceled same day and we were never informed. Had to pay more and worse seating on another airline.

2.0 MediocreAnonymous, May 2026
IAD - MUC
Read more United Airlines reviews

Our flight was canceled same day and we were never informed. Had to pay more and worse seating on another airline.

Our flight to Rome, Italy was cancelled the day of and we were never informed. We only found out because I was trying to get into my husbands account and called to get his account number. Had to pay more for worse seating on another airline.

My service dog and I were asked to deplane just before they closed the door - clearly very last minute they couldn’t find the documentation that I have filled out many many times before that is for flying service animals. I purposely purchase 3seats (a whole row) since he is large and not all passengers want to sit next to a dog on a cross country flight. The plane departed with my husband on it!!! They made me fill out a hard copy of the same form and had to reschedule me on a later flight where they could find 3 seats together!! I’ve done this so many times before - clearly the error was on their part in a technology glitch - but really people - do better!! Very traumatic - and my husband had to wait for us when he landed ….so bad. Poor pup was confused and tired.

First class ticket gets you no seat back entertainment? I have to bring my own laptop to see a movie? And most of their movies have ADS? No thank you. Worse: Tiny snacks only on a 2 hr flight?

Late- that’s what United does best. Missed my connection, rebooked to a flight 17 hours later and had to spend $500 on a hotel. What did I get? A $15 meal voucher. What can you get in an airport for $15. I hate United so much.

Late plane. Only one crew on the ground so we b had to wait for Denver flight to come in, board, and depart. At 78 yrs of age I was not pleased trying to get my connection. What really made me angry was the notification you sent me to hurry up or I would miss my connection. Why tell me to hurry up when you got me in late. It was not a good way of treating customers.

No complaints other than luggage carousel was incorrectly guiding passengers to the wrong carousel on the screen.

Did not like that we couldn't complete check in on-line without providing pictures of our passports. Worry about identity theft. We had no delays and boarding was handled In an efficient manner.

We were a little disappointed to not be able to complete check in online without uploading pics of passports. Also we have KTN's and they weren't on our boarding passes when we got to security. Had to trek back to counter to have them fix.

Excellent service in Polaris class IAD to ZRH. Arrived rested and well fed after the overnight flight.

Premium Economy Good crew, good service, excellent food. Seat back screen just not bright enough.

Flight was delayed an no one cares, or try to help passengers to get the conexión.

Our flight was cancelled while we are on our way to the airport. So, no notice. We were rescheduled to another airline with a 2 hour later takeoff and so arrived at our destination on time. We pre-paid American Airlines $190 to upgrade our seats. No refund. So no use for AA or Kayak.

Terrible, horrible, disappointing- without telling us they changed planes and moved and separated our seats to opposite sides - said they changed seats putting us together - got to airport to find no, they did not - we sat opposing sides of plane - food overly salty to inedible, never saw stewardess but once - it was terrible

The business class layout of chairs was weired. You are sitting directly across stranger.,

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.

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

Information on your arrival and departure airports