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Heathrow

$256+ 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 5/7. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — LHR
May 9 — May 161
Sat 5/9
Sat 5/16
1 adult, Economy
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Cheap 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 April 9, 2026.

This KLM deal was found by Cheapflights users on 4/4. 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.
Sat 5/22:51 pm
PWM
-
LHR
1 stop12h 59m
KLM
Sat 5/911:20 am
LHR
-
PWM
1 stop18h 23m
KLM
Deal found 4/4$722
This Delta deal was found by Cheapflights users on 4/7. 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.
Fri 5/82:38 pm
PWM
-
LHR
1 stop10h 42m
Delta
Wed 5/138:40 am
LHR
-
PWM
2 stops21h 03m
Delta
Deal found 4/7$725
This Delta deal was found by Cheapflights users on 4/7. 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.
Sat 5/24:43 pm
PWM
-
LHR
2 stops15h 32m
Delta
Sat 5/98:40 am
LHR
-
PWM
2 stops19h 29m
Delta
Deal found 4/7$729
This Delta deal was found by Cheapflights users on 4/6. 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 5/74:48 pm
PWM
-
LHR
2 stops14h 22m
Delta
Sun 5/1011:45 am
LHR
-
PWM
2 stops17h 58m
Delta
Deal found 4/6$730
This Delta deal was found by Cheapflights users on 4/7. 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 5/72:38 pm
PWM
-
LHR
1 stop16h 32m
Delta
Thu 5/149:55 am
LHR
-
PWM
2 stops19h 48m
Delta
Deal found 4/7$741
This Delta deal was found by Cheapflights users on 4/7. 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 5/106:25 am
PWM
-
LHR
1 stop18h 55m
Delta
Sat 5/168:55 am
LHR
-
PWM
2 stops20h 48m
Delta
Deal found 4/7$744
This Delta deal was found by Cheapflights users on 4/7. 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.
Wed 5/64:43 pm
PWM
-
LHR
2 stops14h 22m
Delta
Mon 5/118:55 am
LHR
-
PWM
2 stops20h 48m
Delta
Deal found 4/7$745
This Virgin Atlantic deal was found by Cheapflights users on 4/8. 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.
Thu 5/76:00 am
PWM
-
LHR
1 stop19h 25m
Virgin Atlantic
Sun 5/101:25 pm
LHR
-
PWM
1 stop14h 44m
Virgin Atlantic
Deal found 4/8$747
This Delta deal was found by Cheapflights users on 4/8. 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.
Tue 9/224:50 pm
PWM
-
LHR
2 stops15h 25m
Delta
Sun 10/411:45 am
LHR
-
PWM
2 stops17h 14m
Delta
Deal found 4/8$749
This KLM deal was found by Cheapflights users on 4/7. 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 5/102:38 pm
PWM
-
LHR
1 stop14h 42m
KLM
Sat 5/1611:20 am
LHR
-
PWM
1 stop18h 23m
KLM
Deal found 4/7$750

Find 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 April 9, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$722
(KLM)

One-way from

$256
(KLM)

Popular in

July

Cheapest in

October

Average price

$856
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. 21% potential increase in price ($231 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 9% potential price decrease ($79 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in April 2026
Search Deals

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 April 9, 2026.
Use the filters below to find and compare flights from Portland to London Heathrow Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

PortlandLondon

PWM - LHR

PWMLHR

Portland

Fri 5/8

2:38 pm-12:05 pm

1 stop16h 27m

London Heathrow

Mon 5/11

9:55 am-12:43 am

2 stops19h 48m

$725

PortlandLondon

PWM - LHR

PWMLHR

Portland

Fri 9/11

2:35 pm-12:05 pm

1 stop16h 30m

London Heathrow

Tue 9/29

8:55 am-11:59 pm

2 stops20h 04m

$725

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 5/6

2:51 pm-10:20 am

1 stop14h 29m

London Heathrow

Mon 5/11

11:30 am-12:43 am

2 stops18h 13m

$725

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sun 5/10

2:38 pm-6:45 am

1 stop11h 07m

London Heathrow

Sat 5/16

6:30 am-11:09 pm

2 stops21h 39m

$725

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sun 5/10

2:38 pm-10:20 am

1 stop14h 42m

London Heathrow

Sat 5/16

8:20 am-12:43 am

1 stop21h 23m

$731

PortlandLondon

PWM - LHR

PWMLHR

Portland

Fri 9/11

2:35 pm-8:50 am

1 stop13h 15m

London Heathrow

Tue 9/29

9:20 am-10:33 pm

1 stop18h 13m

$731
Quickest round-trip

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 5/7

2:38 pm-6:20 am

1 stop10h 42m

London Heathrow

Thu 5/14

11:30 am-12:43 am

2 stops18h 13m

$741
Cheapest one-way

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 5/7

2:38 pm-8:50 am

1 stop13h 12m

$256

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sat 9/26

12:50 pm-1:15 pm

2 stops19h 25m

$336

PortlandLondon

PWM - LHR

PWMLHR

Portland

Mon 7/6

12:13 pm-6:50 am

1 stop13h 37m

$366

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/8

Showing 1-10 of 18 resultsSorted by cheapest first
1
2

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 April.
ProviderPrice AccuracyTrust Score*
OvagoPrice Accuracy2 starsTrust Score*3 stars
FlightHubPrice 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 FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Portland, Maine-London Heathrow Airport flight deals on Cheapflights vs. FlightHub >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 FlightHub the most. FlightHub 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, October is the cheapest month in which you can book a flight from Portland, Maine to London Heathrow Airport (average of $435). Flying from Portland, Maine to London Heathrow Airport in June is currently the most expensive (average of $591). 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.

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 April 9, 2026.
Read through reviews of airlines operating flights from Portland to London Heathrow Airport, such as United Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
United Airlines
7.4
Good
9,554 reviews

Comfort

7.3

Boarding

7.7

Entertainment

7.1

Food

6.6

Crew

8.1

Overall

7.4

Reviews

1 / 20
10.0
Excellent

Dane,Jan 2026

TYS - IAD

It was a short flight, so no time for amenities. Just glad everything was quick and easy from boarding to arriving at my destination with my family
United Airlines
7.4
Good
9,554 reviews
United Airlines
7.4
Good
9,554 reviews

Comfort

7.3

Boarding

7.7

Entertainment

7.1

Food

6.6

Crew

8.1

Overall

7.4

Reviews

1 / 20
10.0
Excellent

Dane,Jan 2026

TYS - IAD

It was a short flight, so no time for amenities. Just glad everything was quick and easy from boarding to arriving at my destination with my family

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 1 airline has 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 16h 27m. Fly via Delta to get the fastest option. There are 3173 mi between Portland, Maine and London Heathrow Airport.

  • What is the cheapest airline to fly 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..

  • 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, October is the cheapest month in which you can book a flight from Portland, Maine to London Heathrow Airport (average of $435). Flying from Portland, Maine to London Heathrow Airport in June is currently the most expensive (average of $591). 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
Ilford
Hounslow
Croydon
Gatwick
Southend-on-Sea
Harrow
Eastleigh
Dartford
Dover
Winchester
Orpington
Watford
Northampton
Borehamwood
Broadway
Chipping Norton
Hayes
Kingston upon Thames
Eastbourne
Sutton

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for Portland to Heathrow

See prices for flight routes from nearby airports that may be better suited for you.
Boston to Heathrow flights
Boston to Gatwick flights
Boston to Stansted flights
Boston to Luton flights
Bangor to Heathrow flights

Top airline flying from Portland to Heathrow

Discover the top airline 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 April 9, 2026.
AirlineCheapestAverageFlexibilityOn-time
United AirlinesCheapest$648Average$798FlexibilityNo cancel feeOn-time69%

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