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Heathrow

$324+ 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 9/27. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — LHR
Sep 5 — Sep 121
Sat 9/5
Sat 9/12
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 August 6, 2026.

This United Airlines deal was found by Cheapflights users on 8/3. 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.
Mon 11/98:45 am -
1 stop18h 40m
Wed 11/116:50 am -
2 stops21h 31m
Deal found 8/3$738
This Expedia deal was found by Cheapflights users on 8/2. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/256:00 am -
1 stop9h 45m
Mon 9/288:15 am -
1 stop20h 39m
Deal found 8/2$841
This Expedia deal was found by Cheapflights users on 8/2. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/262:40 pm -
1 stop13h 50m
Thu 9/311:55 am -
1 stop17h 30m
Deal found 8/2$864
This United Airlines deal was found by Cheapflights users on 8/5. 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.
Tue 11/102:05 pm -
1 stop11h 35m
Tue 11/246:50 am -
2 stops17h 12m
Deal found 8/5$865
This United Airlines deal was found by Cheapflights users on 8/4. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/103:10 pm -
1 stop14h 55m
Tue 11/176:50 am -
2 stops17h 02m
Deal found 8/4$866
This Delta deal was found by Cheapflights users on 8/3. 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 11/106:00 am -
2 stops20h 45m
Tue 11/176:30 am -
2 stops22h 03m
Deal found 8/3$869
This Air Canada deal was found by Cheapflights users on 8/4. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/78:45 am -
2 stops41h 25m
Fri 11/201:00 pm -
2 stops39h 21m
Deal found 8/4$879
This Air Canada deal was found by Cheapflights users on 8/4. 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/43:10 pm -
2 stops15h 10m
Wed 11/116:00 am -
3 stops22h 21m
Deal found 8/4$883
This United Airlines deal was found by Cheapflights users on 8/6. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/307:25 pm -
2 stops14h 15m
Wed 10/146:50 am -
2 stops16h 22m
Deal found 8/6$884

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 August 6, 2026.

Most accurate provider

Ovago
3 stars

Most trusted provider

Ovago
3 stars

Round-trip from

$738
(United Airlines)

One-way from

$324
(Expedia)

Popular in

June

Cheapest in

February

Average price

$1,210
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. 20% potential increase in price ($295 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 10% potential price decrease ($111 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in August 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 August 6, 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 Portland - LHR London Heathrow

PWMLHR

Portland

Mon 11/9

3:10 pm-10:05 am

2 stops13h 55m

London Heathrow

Wed 11/11

7:40 am-6:52 pm

2 stops16h 12m

$765

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 11/10

4:03 pm-10:30 am

1 stop13h 27m

London Heathrow

Tue 11/24

10:00 am-11:55 pm

2 stops18h 55m

$865

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 11/10

3:10 pm-11:05 am

1 stop14h 55m

London Heathrow

Tue 11/17

6:50 am-6:52 pm

2 stops17h 02m

$865
Quickest round-trip

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Wed 9/30

6:00 am-9:25 pm

1 stop10h 25m

London Heathrow

Wed 10/14

6:50 am-7:24 pm

2 stops17h 34m

$865

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Wed 11/4

10:50 am-6:20 am

1 stop14h 30m

London Heathrow

Wed 11/11

6:50 am-7:02 pm

2 stops17h 12m

$866

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 11/10

6:00 am-7:45 am

2 stops20h 45m

London Heathrow

Tue 11/17

6:30 am-11:33 pm

2 stops22h 03m

$870
Cheapest one-way

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 9/1

6:30 am-6:45 am

2 stops19h 15m

$329
Quickest one-way

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Wed 8/19

6:00 am-8:10 pm

1 stop9h 10m

$329

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Wed 9/2

6:30 am-9:15 am

2 stops21h 45m

$329

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Fri 9/4

6:00 am-6:20 am

1 stop19h 20m

$329

Flights are sorted by cheapest round-trip flights first.

Deals found on 8/5

Showing 1-10 of 15 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 August.
ProviderPrice AccuracyTrust Score*
OvagoPrice Accuracy3 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 Ovago to be most consistent on Cheapflights vs. Ovago Users can find the same prices on Portland, Maine-London Heathrow Airport flight deals on Cheapflights vs. Ovago >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 Ovago the most. Ovago 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.

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 August 6, 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
10,072 reviews

Crew

8.1

Overall

7.4

Food

6.7

Comfort

7.3

Boarding

7.7

Entertainment

7.1

Reviews

1 / 20
2.0
Mediocre

Dawn,Aug 2026

ORD - DEN

I missed my connecting flight because our plane took off ten minutes late and then when we got to the airport another plane was in our shoot waiting to get fueled up and that took 30 minutes so I missed my connecting flight. I asked if I could get off and they assured me the plane would most likely wait for me since they know what time the planes get in because of an app. I was not happy. I had to wait till 7:25 to board the next flight and then that was delayed. Gates changed till 9:20. Terrible
United Airlines
7.4
Good
10,072 reviews
United Airlines
7.4
Good
10,072 reviews

Crew

8.1

Overall

7.4

Food

6.7

Comfort

7.3

Boarding

7.7

Entertainment

7.1

Reviews

1 / 20
2.0
Mediocre

Dawn,Aug 2026

ORD - DEN

I missed my connecting flight because our plane took off ten minutes late and then when we got to the airport another plane was in our shoot waiting to get fueled up and that took 30 minutes so I missed my connecting flight. I asked if I could get off and they assured me the plane would most likely wait for me since they know what time the planes get in because of an app. I was not happy. I had to wait till 7:25 to board the next flight and then that was delayed. Gates changed till 9:20. Terrible

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 9h 45m. Fly via United 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 is the cheapest airline to fly from Portland, Maine to London Heathrow Airport round-trip?

    United Airlines, at $752, was found to be the cheapest airline from Portland, Maine to London Heathrow Airport.. This flight start at 34% 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.

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
Dorking
Hounslow
Winchester
Croydon
Gatwick
Wembley
Harrow
Eastleigh
Southend-on-Sea
Watford
Northampton
Dartford
Chipping Norton
Kingston upon Thames
Eastbourne
Slough
Stansted
Sutton
Luton

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 August 6, 2026.
AirlineCheapestAverageFlexibilityOn-time
United AirlinesCheapest$752Average$1,192FlexibilityNo cancel feeOn-time69%

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