HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Heathrow

$326+ Cheap flights from Portland, ME (PWM) to Heathrow (LHR)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 12/10. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — LHR
Dec 17 — Dec 241
Wed 12/17
Wed 12/24
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Portland to Heathrow with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheap flight deals from Portland to Heathrow

Discover tips and strategies to find the most affordable flight options for your journey from Portland (PWM) to Heathrow (LHR). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated November 17, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$653
(KLM)

One-way from

$326
(Kiwi.com)

Popular in

June

Cheapest in

October

Average price

$799
Provider with most accurate pricing for Portland-London Heathrow flight deals.
Search Deals
Provider most trusted by Cheapflights users for Portland-London Heathrow flights.
Search Deals
From Portland to London Heathrow
Search Deals
One-way flight from Portland to London Heathrow
Search Deals
Highest demand for flights based on searches. 13% potential increase in price ($150 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease ($44 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in November 2025
Search Deals

Find flight deals from Portland to Heathrow

Cheapest flights from Portland to Heathrow
Explore the most affordable flight options available from Portland to Heathrow. Find the lowest fares from popular airlines and budget airlines, with prices last updated on November 17, 2025.

This American Airlines deal was found by Cheapflights users on 11/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/15:37 pmPWM - LHR
1 stop11h 48mAmerican Airlines
Tue 12/97:50 amLHR - PWM
2 stops15h 25mAmerican Airlines
Deal found 11/15$615
This Delta deal was found by Cheapflights users on 11/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/14:53 pmPWM - LHR
2 stops15h 52mDelta
Tue 12/98:40 amLHR - PWM
2 stops20h 19mDelta
Deal found 11/15$623
This Virgin Atlantic deal was found by Cheapflights users on 11/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Virgin Atlantic is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/166:00 amPWM - LHR
1 stop22h 00mVirgin Atlantic
Sun 11/236:30 amLHR - PWM
2 stops20h 49mVirgin Atlantic
Deal found 11/15$669
This Delta deal was found by Cheapflights users on 11/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/1612:48 pmPWM - LHR
2 stops17h 52mDelta
Sun 11/238:40 amLHR - PWM
2 stops18h 39mDelta
Deal found 11/15$674
This KLM deal was found by Cheapflights users on 11/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/164:53 pmPWM - LHR
1 stop10h 52mKLM
Sun 11/234:35 pmLHR - PWM
1 stop12h 19mKLM
Deal found 11/15$697
This Delta deal was found by Cheapflights users on 11/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/112:34 pmPWM - LHR
1 stop11h 21mDelta
Fri 12/191:05 pmLHR - PWM
2 stops15h 16mDelta
Deal found 11/15$701
This American Airlines deal was found by Cheapflights users on 11/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/116:00 amPWM - LHR
1 stop19h 35mAmerican Airlines
Mon 12/157:50 amLHR - PWM
2 stops15h 25mAmerican Airlines
Deal found 11/16$716
This United Airlines deal was found by Cheapflights users on 11/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/317:30 pmPWM - LHR
1 stop10h 20mUnited Airlines
Wed 1/712:05 pmLHR - PWM
2 stops16h 25mUnited Airlines
Deal found 11/16$719
This KLM deal was found by Cheapflights users on 11/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/311:03 pmPWM - LHR
1 stop14h 02mKLM
Wed 1/74:10 pmLHR - PWM
1 stop13h 10mKLM
Deal found 11/16$737

Cheapflights Fare Finder

 
Customize your flight search to find flights from Portland to Heathrow that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated November 17, 2025.
Use the filters below to find and compare flights from Portland to London Heathrow Airport that are best for you.

Fly from

Portland

Fly to

Heathrow

Route

Depart

Return

Price

PortlandLondon

PWM - LHR

PWMLHR

Portland

Mon 12/1

4:53 pm-1:45 pm

2 stops15h 52m

London Heathrow

Tue 12/9

8:40 am-11:59 pm

2 stops20h 19m

$623

PortlandLondon

PWM - LHR

PWMLHR

Portland

Mon 12/1

5:37 pm-10:25 am

1 stop11h 48m

London Heathrow

Tue 12/9

11:45 am-9:37 pm

1 stop14h 52m

$646

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sun 5/10

6:00 am-8:45 pm

1 stop9h 45m

London Heathrow

Sat 5/16

11:55 am-11:36 pm

1 stop16h 41m

$695

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 12/11

6:00 am-8:35 pm

1 stop9h 35m

London Heathrow

Thu 12/18

4:00 pm-11:22 pm

1 stop12h 22m

$697

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 12/11

2:34 pm-6:55 am

1 stop11h 21m

London Heathrow

Fri 12/19

1:05 pm-11:21 pm

2 stops15h 16m

$701

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 12/11

6:00 am-6:35 am

1 stop19h 35m

London Heathrow

Mon 12/15

7:50 am-6:15 pm

2 stops15h 25m

$716

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 12/31

7:30 pm-10:50 am

1 stop10h 20m

London Heathrow

Wed 1/7

12:05 pm-11:30 pm

2 stops16h 25m

$719

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 1/1

1:03 pm-6:20 am

1 stop12h 17m

London Heathrow

Thu 1/8

8:40 am-12:20 am

2 stops20h 40m

$819

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 12/10

6:18 pm-7:30 pm

3 stops44h 12m

$326

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 12/10

3:20 pm-10:50 am

2 stops14h 30m

$399

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/16

Compare providers for flights from Portland to Heathrow

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Portland to Heathrow in November.
ProviderPrice AccuracyTrust Score*
FlightHubPrice Accuracy3 starsTrust Score*1 star
eDreamsPrice Accuracy3 starsTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Portland, Maine-London Heathrow Airport flights, users find the pricing of eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on Portland, Maine-London Heathrow Airport flight deals on Cheapflights vs. eDreams >95% of the time. Price accuracy is based on data collected from Portland, Maine-London Heathrow Airport flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Portland, Maine-London Heathrow Airport flights, Cheapflights users trust eDreams the most. eDreams has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Portland, Maine-London Heathrow Airport flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Portland to Heathrow

Have a flexible travel schedule? Discover the best time to fly to Heathrow from Portland with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Portland to London Heathrow Airport

What is the cheapest month to book a flight from Portland, Maine to London Heathrow Airport?

Currently, January is the cheapest month in which you can book a flight from Portland, Maine to London Heathrow Airport (average of $387). Flying from Portland, Maine to London Heathrow Airport in June is currently the most expensive (average of $595). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from PWM to LHR?

Find hourly flight availability from Portland to Heathrow. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated November 17, 2025.

It’s typically best to fly out from Portland, Maine to London Heathrow Airport in the evening. Doing so could potentially save you 11% on the flight price compared to flying in the morning, which is usually more expensive.

Reviews of airlines servicing Heathrow

Get insights into the airlines that provide service to Heathrow. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Heathrow. Reviews last updated November 17, 2025.
Read through reviews of airlines operating flights from Portland to London Heathrow Airport, such as Delta and United Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Delta
7.9
Good
8,008 reviews

Food

7.3

Boarding

8.1

Crew

8.5

Comfort

7.9

Overall

7.9

Entertainment

7.9

Reviews

1 / 20
6.0
Good

Jim,Nov 2025

AVL - ATL

The exit row seats without a seat in front are great for leg room but don’t have a fold out entertainment console so you’re forced to use the screen several feet in front of you (there is, at least, a remote). Best to bring a tablet loaded with entertainment or a book.
Delta
7.9
Good
8,008 reviews
Delta
7.9
Good
8,008 reviews

Food

7.3

Boarding

8.1

Crew

8.5

Comfort

7.9

Overall

7.9

Entertainment

7.9

Reviews

1 / 20
6.0
Good

Jim,Nov 2025

AVL - ATL

The exit row seats without a seat in front are great for leg room but don’t have a fold out entertainment console so you’re forced to use the screen several feet in front of you (there is, at least, a remote). Best to bring a tablet loaded with entertainment or a book.
United Airlines
7.4
Good
9,014 reviews
Delta
7.9
Good
8,008 reviews

Food

7.3

Boarding

8.1

Crew

8.5

Comfort

7.9

Overall

7.9

Entertainment

7.9

Reviews

1 / 20
6.0
Good

Jim,Nov 2025

AVL - ATL

The exit row seats without a seat in front are great for leg room but don’t have a fold out entertainment console so you’re forced to use the screen several feet in front of you (there is, at least, a remote). Best to bring a tablet loaded with entertainment or a book.

Related info for your journey

Find useful and relevant information for your journey from Portland to Heathrow. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly from for flights from Portland to London Heathrow?

    Portland (PWM) is the airport you will fly out of if you book a flight from Portland to London Heathrow. You should not have trouble finding flights to London Heathrow from Portland; the airport handles an average of 0 outbound flights to London Heathrow per day. You should also have plenty of airline options to choose from since 2 airlines have flights from the Portland airport to London Heathrow. It is only a 2.9 mi journey to Portland (PWM) from Portland’s city center.

  • How long is the flight from Portland, Maine to London Heathrow Airport?

    There are many flights that can get you from Portland, Maine to London Heathrow Airport in 9h 45m. Fly via Delta, American Airlines, or JetBlue to get the fastest option. There are 3173 mi between Portland, Maine and London Heathrow Airport. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the cheapest airlines flying from Portland, Maine to London Heathrow Airport round-trip?

    United Airlines, at $648, was found to be the cheapest airline from Portland, Maine to London Heathrow Airport. An alternate airline flying to your destination would be Delta. These flights start at 33% lower than the current average price 3 months from now.

  • Can I find deals for flights from Portland to Heathrow that include hotel bookings?

    Yes. In addition to deals on Portland to Heathrow flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Portland to Heathrow?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Portland to Heathrow.

  • Can I find deals for business class flights from Portland to Heathrow?

    Yes. Cheapflights offers flight deals from Portland to Heathrow by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Portland, Maine to London Heathrow Airport?

    Currently, January is the cheapest month in which you can book a flight from Portland, Maine to London Heathrow Airport (average of $387). Flying from Portland, Maine to London Heathrow Airport in June is currently the most expensive (average of $595). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near London Heathrow Airport?

Book flights to London Heathrow Airport if you plan to visit one of these locations
Hounslow
Ilford
Hayes
Southend-on-Sea
Harrow
Croydon
Eastleigh
Dartford
Dover
Winchester
Orpington
Northampton
Gatwick
Borehamwood
Broadway
Aylesbury
Bedford
Chipping Norton
Wembley
Folkestone

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Top 2 airlines flying from Portland to Heathrow

Discover the top 2 airlines that operate flights from Portland to Heathrow. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated November 17, 2025.
AirlineCheapestAverageFlexibilityOn-time
United AirlinesCheapest$648Average$924FlexibilityNo cancel feeOn-time69%
DeltaCheapest$825Average$963FlexibilityNo cancel feeOn-timeN/A

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.