PWM - LON

$326 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 12/10. 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
$653
Overall average: $789
KLM
Sat 2/7Sat 2/14
PWM - LHR • 1 stop
Cheapest one-way
$326
Multiple Airlines
Wed 12/10
PWM - LGW • 3 stops
Top airlines
KLM
Cheapest • from $653 (round-trip)
Delta
Best reviews • 7.9 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
When to travel
October
Cheapest • 29% price drop
April
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
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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

Sat, Feb 7 - Sat, Feb 14
KLM Logo
2:35 pm - 8:05 amPWM-LHR
12h 30m1 stop
KLM Logo
8:55 am - 11:04 pmLHR-PWM
19h 09m1 stop
$653KLM
Find Deal
Sat, Feb 7 - Sat, Feb 14
Delta Logo
12:48 pm - 9:00 amPWM-LHR
15h 12m2 stops
Delta Logo
8:55 am - 11:04 pmLHR-PWM
19h 09m1 stop
$658Delta
Find Deal
Fri, Jan 23 - Tue, Jan 27
Delta Logo
2:35 pm - 9:30 amPWM-LCY
13h 55m2 stops
Delta Logo
8:40 am - 10:27 pmLCY-PWM
18h 47m2 stops
$661Delta
Find Deal
Sat, Feb 7 - Sat, Feb 14
United Airlines Logo
2:31 pm - 7:10 amPWM-LHR
35h 39m2 stops
United Airlines Logo
11:05 am - 6:56 pmLHR-PWM
36h 51m2 stops
$689United Airlines
Find Deal
Thu, Dec 11 - Mon, Dec 15
American Airlines Logo
6:00 am - 6:35 amPWM-LHR
19h 35m1 stop
American Airlines Logo
7:50 am - 6:15 pmLHR-PWM
15h 25m2 stops
$716American Airlines
Find Deal
Wed, Dec 31 - Wed, Jan 7
United Airlines Logo
7:30 pm - 10:50 amPWM-LHR
10h 20m1 stop
United Airlines Logo
12:05 pm - 11:30 pmLHR-PWM
16h 25m2 stops
$719United Airlines
Find Deal
Thu, Dec 11 - Mon, Dec 15
American Airlines Logo
12:39 pm - 7:00 amPWM-LHR
13h 21m2 stops
American Airlines Logo
7:50 am - 6:15 pmLHR-PWM
15h 25m2 stops
$720American Airlines
Find Deal
Thu, May 14 - Thu, May 21
Multiple Airlines Logo
4:50 pm - 2:40 pmPWM-LGW
16h 50m2 stops
Multiple Airlines Logo
1:00 pm - 11:36 pmLGW-PWM
15h 36m2 stops
$1,066Multiple Airlines
Find Deal
Sun, May 17 - Sun, May 31
Turkish Airlines Logo
6:00 am - 9:55 amPWM-LGW
22h 55m2 stops
Turkish Airlines Logo
7:00 am - 11:36 pmLGW-PWM
21h 36m2 stops
$1,449Turkish Airlines
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Sat, Jan 3 - Thu, Jan 8
Multiple Airlines Logo
6:18 pm - 6:00 amPWM-LGW
30h 42m2 stops
Multiple Airlines Logo
2:00 pm - 9:07 amLGW-PWM
24h 07m1 stop
$1,672Multiple Airlines
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.

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 $619 (return) on average. On the other hand, the most expensive months are June and July, where the average cost of round-trip tickets is $1,242 and $1,188 respectively.

Good to know

Low seasonFebruary
Cheapest flight$326
Best time to beat the crowds with an average 18% drop in price.
Most popular time to fly and prices are also 14% lower on average.
Flight from Portland to London

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 $326 for a one-way ticket and $653 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 $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 $853 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 3 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 8007 reviews
8.1Boarding
7.9Entertainment
7.9Comfort
8.5Crew
7.3Food
Airline reviews

Our flight from SFO to MSP was right on time on 11/15/2025. No delays. As we approached MSP at about 8 pm, we circled in the air until 8:40 pm so I don't call that efficient for MSP. I think the captain should announce the delay and why. (as if we all don't know that we are just circling around the area, slowing down, speeding up, slowing down.) Thank you. Marilyn Fischer

8.0 ExcellentAnonymous, Nov 2025SFO - MSP
Read more Delta reviews

Our flight from SFO to MSP was right on time on 11/15/2025. No delays. As we approached MSP at about 8 pm, we circled in the air until 8:40 pm so I don't call that efficient for MSP. I think the captain should announce the delay and why. (as if we all don't know that we are just circling around the area, slowing down, speeding up, slowing down.) Thank you. Marilyn Fischer

Service in business class was not impressive. I ordered coffee with dinner and then watched other people get 2 refills before I got my 1 cup of coffee, and only after I pressed the attendant button overhead. Furthermore, the seats in the forward cabin need maintenance on this 737-800: the upholstery is detaching from the seat frame, at least on the backs of seats 1C, 1D.

Plenty of leg room, temperature was great and staff was excellent. Would do it more often.

The ticket agents in West Palm Beach on Friday afternoon Nov. 7th were incredible in getting us on an earlier plane to Atlanta during the government shutdown. Had the taken our original flight we would have missed our connection. She did this on her own, We didn't even have to ask, and she did it all with a smile and showing genuine concern that we would be taken care of. We are very grateful and thankful. We fly often, and now we will be sure to fly Delta.

Flight delayed then cancelled. Misplaced luggage. Still do not have. Rented car 1100 mile drive. I had to buy some overnight Hotels clothes toiletries gas food at my expense. Still not home. Not sure where luggage is. Over 4 hours on hold to Felta

I truly love flying with Delta. They have always treated me with the upmost respect

Our flight attendant in FIRST CLASS was one of the worst I’ve ever had. She was not at all pleasant, nor particularly good at her service.

Everything went well and was good. Nothing exceptional, but no complaints either. Cheap seats are pretty comfortable.

Staff were friendly and happy. Delta could make sure passengers that don't have the app know of changes. Without Kayak I would not have known about the change of gate or the delay. Kayak was faster to notify me.

They ended up paying for the bag twice, but the counter wouldn't take my baggage receipt. Left it to me to resolve. Not sure how to resolve the issue.

Even though we were delayed, we were able to make our connection

Seats in waiting area and on plane hard as rock. Fast internet on the flight was great! Crew was kind.

Starlink wifi on the Embraer E175 is an excellent experience. I was able to connect and work from IAD all the way to approach into BTV.

Older aircraft, no meal, only food was for purchase. Not impressed United.

United needs to step up their game. Delayed flight leaving Seattle, San Francisco. Older aircraft, not very comfortable.

Always wish for more healthy, gluten free options. We have to bring our own.

Having a long layover, I was very appreciative of the ability to stand by for an earlier flight. Other airlines like Delta have refused this to me in the past, just to be mean (because my ticket class wasn't high enough). United went out of their way to help me get to my destination early, which I really appreciated given that it was the third leg of a 24+ hour journey for me.

Other than a way way too cold cabinets for the entire flight, all was great

One bag is incorrect and not acceptable for an international flight. The food was not just good. I won't fly with them again.

Not pleasant trip cross country when the entertainment and WiFi system not working. No entertainment for entirety of route. Staff was rather nonchalant in that they dismissed the problem due to age of plane. It would have been nice to know this up front so I could have come prepared to read or download movies before boarding Coincidentally or not, there was a similar issue with the entertainment system on my previous flight I took on my fist leg of the trip. There are no seat TVs, so you must rely on the app when it works. United can do better. Also, what use it it to pay for boarding group 2 when half of the passengers are in the same line as you?

Checking In on JetBlue site was impossible. It hung up on REAL ID. Even my Global Entry did not help. Luckily, on Kayak site it was a breeze. Entire flight the temperature was COLD! Otherwise the crew was great!

The flight was two hours late due to a computer fault and resulting maintenance. Nothing was offered as compensation beyond bottles of water during the time we were deplaned and waiting in the terminal.

Very pleasant flight attendants. Gate crew rather loud chatting with each other.

Four plus hour flight delay in New York caused us to take off after 11:30pm. We didn’t arrive at our hotel until five hours after check in. Started the trip off feeling exhausted.

Plane was in bad shape. TV’s and WiFi didn’t work. Plane need a refresh. Not enough room for bags.

There was a fowl odour coming from the lavatory the entire flight

Everything was great. I liked the text updates so that I never miss a gate change & I have all the latest info.

I don’t usually fly budget airlines or airlines in the United States. It was as good as any other airline. The seats are comfortable and the airline attendants are not rude & surly. Very nice flight (s).

No internet on a flight over three hours in this age is criminal. Staff inattentive and dismissive

They have the most inexperienced / rude flight staff I’ve encountered

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

Information on your arrival and departure airports