PWM - LON

$259 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 5/9. 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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Everything you should know

Cheapest round-trip
$741
Virgin Atlantic
Mon 4/27Fri 5/1
PWM - LHR • 1 stop
Cheapest one-way
$259
Delta
Sat 5/9
PWM - LHR • 2 stops
Top airlines
Cheapest • from $741 (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

Mon, Apr 27 - Fri, May 1
Virgin Atlantic Logo
5:21 am - 6:25 am
PWM
-
LHR
20h 04m
1 stop
Virgin Atlantic Logo
1:25 pm - 11:23 pm
LHR
-
PWM
14h 58m
1 stop
$741Virgin Atlantic
Thu, Apr 30 - Fri, May 15
Delta Logo
12:46 pm - 7:10 am
PWM
-
LHR
13h 24m
1 stop
Delta Logo
8:40 am - 11:09 pm
LHR
-
PWM
19h 29m
2 stops
$747Delta
Fri, May 8 - Wed, May 13
Delta Logo
2:38 pm - 7:15 am
PWM
-
LHR
11h 37m
1 stop
Delta Logo
9:55 am - 11:12 pm
LHR
-
PWM
18h 17m
2 stops
$749Delta
Thu, May 7 - Sun, May 10
Delta Logo
2:38 pm - 7:15 am
PWM
-
LHR
11h 37m
1 stop
Delta Logo
11:45 am - 12:43 am
LHR
-
PWM
17h 58m
2 stops
$750Delta
Sun, May 10 - Sat, May 16
Delta Logo
2:38 pm - 8:50 am
PWM
-
LHR
13h 12m
1 stop
Delta Logo
6:30 am - 12:43 am
LHR
-
PWM
23h 13m
2 stops
$751Delta
Tue, Sep 22 - Sun, Oct 4
Delta Logo
2:35 pm - 6:20 am
PWM
-
LHR
10h 45m
1 stop
Delta Logo
11:30 am - 11:59 pm
LHR
-
PWM
17h 29m
2 stops
$752Delta
Fri, May 8 - Wed, May 13
KLM Logo
2:38 pm - 8:50 am
PWM
-
LHR
13h 12m
1 stop
KLM Logo
4:05 pm - 12:43 am
LHR
-
PWM
13h 38m
1 stop
$756KLM
Mon, Apr 27 - Fri, May 1
Air France Logo
2:51 pm - 9:40 am
PWM
-
LGW
13h 49m
2 stops
Air France Logo
5:00 pm - 2:11 pm
LGW
-
PWM
26h 11m
2 stops
$762Air France
Tue, Sep 22 - Sun, Oct 4
Multiple Airlines Logo
5:09 pm - 10:00 am
PWM
-
LGW
35h 51m
2 stops
Multiple Airlines Logo
2:00 pm - 9:08 am
LGW
-
PWM
24h 08m
1 stop
$971Multiple Airlines
Wed, May 13 - Wed, May 20
Multiple Airlines Logo
7:20 am - 8:35 am
PWM
-
LCY
20h 15m
2 stops
Multiple Airlines Logo
1:45 pm - 11:03 pm
LCY
-
PWM
14h 18m
2 stops
$1,327Multiple 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 April.

Good to know

Low seasonOctober
Cheapest flight$259
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 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 $259 for a one-way ticket and $741 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 9589 reviews
7.1Entertainment
7.3Comfort
7.7Boarding
6.6Food
8.1Crew
Airline reviews

It was a red-eye, but the flight felt surprisingly quick. The seats were very comfortable, and that made resting much easier. I also want to thank the gentleman seated next to me, who graciously moved so my mom could sit beside me. We slept almost the entire way. The cabin crew was respectful in not disturbing us, while also being courteous and professional throughout. Thank you, United.

10.0 ExcellentHartaj, Apr 2026
SFO - RDU
Read more United Airlines reviews

It was a red-eye, but the flight felt surprisingly quick. The seats were very comfortable, and that made resting much easier. I also want to thank the gentleman seated next to me, who graciously moved so my mom could sit beside me. We slept almost the entire way. The cabin crew was respectful in not disturbing us, while also being courteous and professional throughout. Thank you, United.

Packed in plane small uncomfortable seats elbow to elbow nobody wants to be in that situation for the money they paid

Vegetarian selection could be better. Bread was too hard to chew.

Crew was friendly and competent. Food, wine, and entertainment were excellent except the raw tuna on the flight to Split. Recommend against serving that - at least as the only option. Many medical conditions do not allow people to eat raw fish.

Overall flight was ok. Flight attendant was receptive to assisting passengers with tight connections.

Checking in united could not figure out my star alliance gold. Baggage did not get marked priority and didn't receive boarding passes. When got to SFO lounge personal fixed everything Immediately

Very comfortable flight, snacks and drinks were good, good communication from crew. Could have used a little more information on timing of boarding for group 5

It's a long flight and I would have liked better snacks between lunch and the arrival meal. It's fine to have fruit and nuts but I really don't like ramen because it's salty junk soup. I'd suggest sandwiches. They're not expensive nor are they hard to store for a long flight. The FA's had a couple of big services and they were super busy preparing, executing and then cleaning up. Then they disappeared.

Great flight. Got to watch a movie. Smooth flight and early arrival at ORD.

This was the first flight in the morning. We boarded fine. The cabin door was closed and we were ready to go. We were notified by the Captain that ATC issued and ground stop for 40 minutes. So, without even pushing back from the gate, we were already 40 minutes late. We actually were released to push-back and taxi at 30 minutes. But, some passengers had tight connections and were not going to make their connections. Some passengers asked about the delay and the effect on the connections and were told by the cabin attendant that all flights will be delayed and so they should be OK. However, that was not true. My connecting flight was on time and I arrived at IAH with 21 minutes to make my connection. I did and I'm happy about that, but the flight crew should not have given assurances to the passengers who might have missed their connections.

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