PWM - LON

$390 Find Cheap Flights from Portland to London

This is the cheapest round-trip flight price found by a KAYAK user in the last 72 hours by searching for a flight from Portland to London departing on 1/21. 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, 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
$602
Overall average: $782
Delta
Wed 1/21Wed 1/28
PWM - LHR • 1 stop
Cheapest one-way
Multiple Airlines
Thu 1/8
PWM - LON • multi-stop
Top airlines
Virgin Atlantic
Cheapest • from $571 (round-trip)
Delta
Best reviews • 7.9 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
When to travel
October
Cheapest • 28% price drop
April
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, Jan 21 - Wed, Jan 28
Delta Logo
5:30 am - 7:50 am
PWM
-
LHR
21h 20m1 stop
Delta Logo
6:20 am - 12:20 am
LHR
-
PWM
23h 00m2 stops
$602Delta
Wed, Jan 21 - Fri, Jan 30
Delta Logo
6:00 am - 9:20 am
PWM
-
LHR
22h 20m1 stop
Delta Logo
10:00 am - 12:20 am
LHR
-
PWM
19h 20m2 stops
$603Delta
Wed, Jan 21 - Thu, Jan 29
Delta Logo
2:35 pm - 7:50 am
PWM
-
LHR
12h 15m2 stops
Delta Logo
11:30 am - 12:20 am
LHR
-
PWM
17h 50m2 stops
$607Delta
Wed, Jan 21 - Tue, Feb 3
Delta Logo
2:35 pm - 7:50 am
PWM
-
LHR
12h 15m2 stops
Delta Logo
11:45 am - 12:20 am
LHR
-
PWM
17h 35m2 stops
$608Delta
Wed, Jan 21 - Tue, Jan 27
KLM Logo
2:35 pm - 10:15 am
PWM
-
LHR
14h 40m1 stop
KLM Logo
4:35 pm - 12:20 am
LHR
-
PWM
12h 45m1 stop
$609KLM
Tue, Mar 31 - Tue, Apr 14
KLM Logo
12:51 pm - 8:55 am
PWM
-
LHR
15h 04m1 stop
KLM Logo
1:25 pm - 11:23 pm
LHR
-
PWM
14h 58m1 stop
$625KLM
Tue, Feb 17 - Tue, Feb 24
American Airlines Logo
5:40 pm - 10:25 am
PWM
-
LHR
11h 45m1 stop
American Airlines Logo
7:50 am - 6:11 pm
LHR
-
PWM
15h 21m2 stops
$628American Airlines
Fri, Feb 20 - Fri, Feb 27
United Airlines Logo
4:15 pm - 11:15 am
PWM
-
LHR
14h 00m1 stop
United Airlines Logo
11:10 am - 11:20 pm
LHR
-
PWM
17h 10m2 stops
$630United Airlines
Tue, Mar 3 - Thu, Mar 12
Multiple Airlines Logo
6:14 pm - 9:45 am
PWM
-
LGW
34h 31m2 stops
Multiple Airlines Logo
2:00 pm - 9:07 am
LGW
-
PWM
23h 07m1 stop
$1,021Multiple Airlines
Mon, Apr 20 - Sat, Apr 25
Multiple Airlines Logo
9:47 am - 10:00 am
PWM
-
LGW
19h 13m1 stop
Multiple Airlines Logo
12:40 pm - 3:58 pm
LGW
-
PWM
32h 18m2 stops
$1,537Multiple 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.

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 $599 (return) on average. On the other hand, the most expensive months are June and July, where the average cost of round-trip tickets is $1,208 and $1,188 respectively.

Good to know

Low seasonJanuary
Cheapest flight$602
Best time to beat the crowds but there is an average 3% increase 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 $571 for a round-trip ticket.

  • 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 $769 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 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 8025 reviews
7.9Comfort
8.1Boarding
7.2Food
7.8Entertainment
8.5Crew
Airline reviews

It was Delta, but the flight attendants were stressful and disrespectful. I am a diamond member a travel weekly. I have not had a negative thing to share in quite some time. But this was noticeable.

2.0 MediocreWilliam, Jan 2026
LGA - BOS
Read more Delta reviews

It was Delta, but the flight attendants were stressful and disrespectful. I am a diamond member a travel weekly. I have not had a negative thing to share in quite some time. But this was noticeable.

Comfort Plus seat 11E seemed smaller than prior flights. The movie selection is good. Watched most of the most recent Tron movie. I'll watch the remaining part later as my movie is saved in the Delta Seatback Experience.

Flight was late from Newark to Atlanta, I asked flight attendant to please let my family of 3 out first when we landed to Atlanta because we were late for our connecting flight to Quito. She didn't and we were late for 5 minutes we couldn't board the plane and spend hours trying to get another flight with customer service for the next day.

I really liked the legroom. I am 6’4”.a at For some reason our seats were not together and using the app to fix it didn’t work. Passengers were nice enough to move for us but you should absolutely ensure a parent sits with their child.

Late delayed flight delays boarding and delays leaving and delays on arrival too. Cramped plane no room no food.

DTW line is too long. The flights from DTW to BWI are always delayed for unknown reasons.

Delta canceled our flight and we had to scramble to find another airline to get home. Phoenix is not a delta hub so they didn’t have another plane. It would have been a red eye though Salt Lake City. Getting in at 5am. No bueno.

This flight was no comparison to our prior flight. I'm thinking it all has to do with the age of the aircraft.

This flight was a first class choice and left much to be desired. Seat backs on seats were falling apart and torn. Seats actually didn't come to a "full & upright position". Pull out table was sprung. Not any significant leg room. All in all we were on an obviously older plane and felt overcharged for what we received as first class.

A 12 hour flight during the day with one real meal service - are you kidding? Also the breakfast was one of the worst and not what was listed

Check-in, boarding and the flight from Phoenix to Houston was quick and easy. The flight from Houston to Shreveport was delayed 5 hours. It was frustrating but I think United handled it the best they could.

Some flight attendants were great others were cranky. Seats were very tight and sitting on an aisle was very hard as the carts and people walking constantly bumped shoulder and arm.

It was great with United overall except for two things. 1) It was a 5-hour flight and we were with kids, so we were asking for extra snacks. They were extremely reticent to dole them out even though there wasn't any meal and the kids were starting to hit their limit towards the end. 2) Baggage didn't arrive until 80 minutes after we landed.

They lost my luggage, so, not happy. The crew was nice but my suitcases never made it, still trying to find out what happened!

The staff was hospitable and professional. The seat had a bit of wear. The winner shade was stuck 1/4 open. I received the best of both worlds. The morning sun was able to come in and blind the screen i was trying to use while at the same time it was too low to look out and enjoy the view. Rather embarrassing for a 1st class ticket.

Perfect flight. Smooth flight. Arrived 20 minutes early at destination. Excellent service.

The flights were on time which was great give. It was holiday travel season and there’d been some weather issues. The only complaint and this is every time with United is the terrible seat design. The head rest is not built for comfort and having my neck bent forward for a cross country trip reminded me while I try not to take United flights as a rule.

I’m so sorry, I can’t remember her name, I believe it was Dimpti. She was stellar, also a mature Asian flight attendant, lots of flowers in her hair, just as amazing! But literally the crew was AWESOME . Only downside is there weren’t any charging outlets. Maybe I needed to ask a flight attendant , but it would’ve been nice to have one easily accessible.

The flight was delayed by two de-icings. The seatbelt did not work correctly. It did not stay tight.

Everything was absolutely wonderful from check in to baggage claim. Staff was very professional and sweet. Will definitely recommend United to family and friends.

Flight was fine, price was good but food onboard was abysmal. I was on there for breakfast and lunch and dinner 845am EST to 845pm GMT and all I got was a yoghurt parfait, fruit and a piece of cake. Later snacks included an ice-cream brownie and a pizza twist. I was hungry by the time I landed and the airport amenities were closed. Not happy.

1) No pilot available for 1 hour 2) no room for most passengers careyon in overhead—-> stowed below 3) when we landed we had to wait 45 min. Before docking at gate as gate was not ready

Good. No issues except a slight delay. Crew came in late.

Not a pleasant experience, service was poor. Didn't like it

It was good. I prefer JB over other airlines.I just wish we had headphones for the films, but other than that - good.

The ride share experience in JFK is terrible. After traveling on a flight, then you need to take a subway to the last stop to get an uber or lyft. Unacceptable. Bad job JetBlue for permitting JFK and Port Authority to do this to your passengers.

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.

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

Information on your arrival and departure airports