PWM - LHR

$628 Find Cheap Flights from Portland to London Heathrow Airport

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 1/29. 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 Heathrow Airport

 
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
$628
Typical prices: $768-$786
United Airlines
Thu 1/29Thu 2/5
PWM - LHR • 1 stop
Cheapest one-way
Multiple Airlines
Tue 12/16
PWM - LHR • multi-stop
Top airlines
United Airlines
Cheapest • from $628 (round-trip)
Delta
Best reviews • 7.9 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
When to travel
October
Cheapest • 22% price drop
September
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-LHR)

 
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

Thu, Jan 29 - Thu, Feb 5
United Airlines Logo
3:12 pm - 6:20 am
PWM
-
LHR
10h 08m1 stop
United Airlines Logo
6:50 am - 6:50 pm
LHR
-
PWM
17h 00m2 stops
$628United Airlines
Thu, Jan 29 - Thu, Feb 5
United Airlines Logo
3:12 pm - 10:50 am
PWM
-
LHR
14h 38m2 stops
United Airlines Logo
6:50 am - 6:50 pm
LHR
-
PWM
17h 00m2 stops
$633United Airlines
Sun, Jan 11 - Sun, Jan 18
Delta Logo
2:35 pm - 8:10 pm
PWM
-
LHR
24h 35m1 stop
Delta Logo
6:30 am - 12:20 am
LHR
-
PWM
22h 50m2 stops
$635Delta
Wed, Jan 21 - Sun, Jan 25
United Airlines Logo
2:31 pm - 6:40 am
PWM
-
LHR
11h 09m1 stop
United Airlines Logo
1:25 pm - 2:31 pm
LHR
-
PWM
30h 06m2 stops
$637United Airlines
Wed, Jan 21 - Sun, Jan 25
Air Canada Logo
6:00 am - 7:10 am
PWM
-
LHR
20h 10m2 stops
Air Canada Logo
1:25 pm - 11:30 pm
LHR
-
PWM
39h 05m2 stops
$640Air Canada
Tue, Mar 31 - Tue, Apr 14
Delta Logo
2:30 pm - 7:15 am
PWM
-
LHR
11h 45m1 stop
Delta Logo
6:30 am - 10:03 pm
LHR
-
PWM
20h 33m2 stops
$645Delta
Tue, Mar 31 - Tue, Apr 14
Delta Logo
4:50 pm - 1:10 pm
PWM
-
LHR
15h 20m2 stops
Delta Logo
9:55 am - 11:59 pm
LHR
-
PWM
19h 04m2 stops
$649Delta
Sun, Jan 11 - Sun, Jan 18
Austrian Airlines Logo
8:35 am - 8:25 am
PWM
-
LHR
18h 50m1 stop
Austrian Airlines Logo
6:00 pm - 6:50 pm
LHR
-
PWM
29h 50m1 stop
$653Austrian Airlines
Sun, Mar 29 - Wed, Apr 15
JetBlue Logo
6:00 am - 8:45 pm
PWM
-
LHR
9h 45m1 stop
JetBlue Logo
11:55 am - 11:36 pm
LHR
-
PWM
16h 41m1 stop
$655JetBlue
Thu, Jan 29 - Thu, Feb 5
Austrian Airlines Logo
8:40 am - 8:25 am
PWM
-
LHR
18h 45m1 stop
Austrian Airlines Logo
8:00 am - 6:50 pm
LHR
-
PWM
15h 50m1 stop
$656Austrian 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 Heathrow Airport?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Portland to London Heathrow Airport, 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 Heathrow Airport is October, where tickets cost $752 (return) on average. On the other hand, the most expensive months are December and June, where the average cost of round-trip tickets is $1,472 and $1,460 respectively.

Good to know

Low seasonJanuary
Cheapest flight$628
Best time to beat the crowds with an average 20% drop in price.
Most popular time to fly with an average 1% increase in price.
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 Portland to London Heathrow Airport flights

  • What is the cheapest flight from Portland to London Heathrow Airport?

    In the last 3 days, the lowest price for a flight from Portland to London Heathrow Airport was $628 for a round-trip ticket.

  • Do I need a passport to fly between Portland and London Heathrow Airport?

    Yes

  • Which airports will I be using when flying from Portland to London Heathrow Airport?

    When flying out of Portland you will be using Portland. You will be landing at London Heathrow Airport, also known as London Heathrow.

  • Which aircraft models fly most regularly from Portland to London Heathrow Airport?

    We unfortunately don’t have that data for this specific route.

  • Which airline alliances offer flights from Portland to London Heathrow Airport?

    SkyTeam, and Star Alliance are the airline alliances operating flights between Portland and London Heathrow Airport, 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 $963 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 $874 and an overall rating of 7.4.

  • How does KAYAK find such low prices on flights from Portland to London Heathrow Airport?

    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 Heathrow Airport.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Portland to London Heathrow Airport?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to London Heathrow Airport 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 Heathrow Airport?

    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 Heathrow Airport with an airline and back to Portland with another airline. Booking your flights between Portland and LHR can sometimes prove cheaper using this method.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Portland to London Heathrow Airport?

    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 Heathrow Airport 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.
7.9
DeltaOverall score based on 8010 reviews
7.9Entertainment
8.1Boarding
7.3Food
8.5Crew
7.9Comfort
Airline reviews

I noticed that the planes seem to be outdated. There was no entertainment per se. Also, the waiting area did not have any working electrical outlets

10.0 ExcellentMargaret, Dec 2025
BOS - PIT
Read more Delta reviews

I noticed that the planes seem to be outdated. There was no entertainment per se. Also, the waiting area did not have any working electrical outlets

None of the airplane features were available during the flight.

Original flight was cancelled and when i was rebooked by the airline, they couldn't seat me in the same type of seat as I had originally booked (went from window/aisle to middle/middle and one was a bulkhead seat, and other wasn't in the same class)

Lady Pilot was perfect in every way wheels up to wheels down communication, professionalism, excellent on time departure and on time arrival, excellent communication! Fantastic job with Superb attitude!!

The food is terrible. The staff is wonderful. Comfort is good.

Left on time, a bit delayed due to headwinds most of the trip.

I fly Delta all the time, have Platinum Medallion status. But this route seems to have major problems with delays and seems to never leave on time! Have only taken it twice in the last two weeks, and each time it had delays of more than 1 hour... very disappointed!!!!

Getting to the flight was arduous and lengthy. The flight itself was good but the food option wasn’t a good selection. I need to do a Kosher option on my return. Flight crew were nice

Good seats in Main cabin, excellent service and excellent landing

My flight was cancelled with no explanation after I had already cleared security. I was given 4 options to rebook, only one being non-stop like I had paid for. I grabbed it. It was 4 plus hours later and then took off even later. Biggest complaint is that I booked early and had an aisle seat. They gave me a "window" seat in front of the exit row, so the seat did not decline. I weigh all of 103 #s and it was tight for me! For what I paid, I feel I was kind of ripped off. I think they should have given me the empty comfort seat for the inconvenience. There was no apology nor any explanation as to why the flight was cancelled. My guess is it benefitted Delta in some way.

The flight was on time. I generally don’t drink or eat on short flights and the seats were good and the flight attendants were friendly. That’s all I expect

It was nice to have gotten up upgraded to first class with a meal on a three hour flight

Not great experience - we were super late boarding due to issues with aircraft. Then when we finally all got onboard and seated and they started taxiing out to the runway they just stopped then turned around and went back to the airport. Apparently the crew “ran out of time” to legally fly us. They mentioned that they were about 2 minutes away from taking off. I understand the rules and safety but kinda wonder why they would have bothered boarding us in the first place? Had to go all the way back and de plane and then wait in a HUGE line to get a hotel (this is somewhere around 2:30am) finally got to hotel by Uber (no shuttle after 20min so gave up) and they ended up putting us all back on the same aircraft at 10am next morning so got about 2.5 hours sleep. They did give us. $250 credit, but it was a São Paulo Brazil flight out of Dulles. The flight and everything was fine.

United overall experience is great these days. Airport experience was very organized. Staff on flight were great. App and information as good as it gets.

United have really come back. Airport and boarding process is clear and good, app and information also very good

They charged a fee for 1st bag checked. Others in same party were free.

Flight was delayed 8 times. We were sitting at the airport for 14 hours. We got 2 hours of sleep (if that) on what was not meant to be a red-eye.

The movies offered were great. Staff were very pleasant and very efficient.

After a delay at the gate, C3, at Ohare on Sunday, I left my Blk ski coat on the bench at the gate, lost! Please review my lob claim, thx.

Very bad! They kept delaying my flight and wouldn’t do anything about it

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

Information on your arrival and departure airports