HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Heathrow

$329+ 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 9/25. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — LHR
Sep 11 — Sep 181
Fri 9/11
Fri 9/18
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

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 12, 2026.

This United Airlines deal was found by Cheapflights users on 8/10. 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 8/10$739
This Delta deal was found by Cheapflights users on 8/11. 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 11/102:15 pm -
1 stop13h 45m
Tue 11/246:30 am -
2 stops22h 03m
Deal found 8/11$866
This United Airlines deal was found by Cheapflights users on 8/7. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/76:00 am -
2 stops44h 10m
Fri 11/206:50 am -
2 stops21h 31m
Deal found 8/7$869
This Delta deal was found by Cheapflights users on 8/7. 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.
Tue 11/1012:50 pm -
2 stops17h 50m
Tue 11/178:40 am -
2 stops19h 53m
Deal found 8/7$870
This United Airlines deal was found by Cheapflights users on 8/11. 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.
Sat 12/55:06 pm -
2 stops33h 04m
Wed 12/911:10 am -
2 stops16h 47m
Deal found 8/11$873
This Air Canada deal was found by Cheapflights users on 8/9. 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.
Tue 11/33:41 pm -
2 stops14h 39m
Tue 11/176:00 am -
3 stops22h 21m
Deal found 8/9$883
This Air Canada deal was found by Cheapflights users on 8/11. 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.
Tue 11/108:45 am -
3 stops18h 45m
Tue 11/176:00 am -
3 stops22h 21m
Deal found 8/11$886
This Expedia deal was found by Cheapflights users on 8/11. 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.
Sun 9/206:00 am -
1 stop9h 45m
Sun 9/2711:55 am -
1 stop16h 59m
Deal found 8/11$887
This United Airlines deal was found by Cheapflights users on 8/11. 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 11/105:50 am -
1 stop9h 45m
Tue 11/1712:00 pm -
1 stop16h 21m
Deal found 8/11$895

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 12, 2026.

Most accurate provider

Ovago
3 stars

Most trusted provider

Ovago
3 stars

Round-trip from

$739
(United Airlines)

One-way from

$329
(JetBlue)

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 12, 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

8:45 am-8:25 am

1 stop18h 40m

London Heathrow

Wed 11/11

6:50 am-11:21 pm

2 stops21h 31m

$739

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 11/3

2:05 pm-10:50 am

1 stop15h 45m

London Heathrow

Tue 11/17

6:50 am-6:52 pm

2 stops17h 02m

$866

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Sat 11/7

10:50 am-8:35 pm

1 stop28h 45m

London Heathrow

Fri 11/20

6:50 am-9:00 am

2 stops31h 10m

$866

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 11/3

6:01 am-9:00 am

1 stop21h 59m

London Heathrow

Tue 11/17

12:40 pm-11:33 pm

1 stop15h 53m

$895
Quickest round-trip

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Mon 9/21

6:53 pm-10:25 am

1 stop10h 32m

London Heathrow

Mon 9/28

6:50 am-7:24 pm

2 stops17h 34m

$896
Cheapest one-way

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Fri 9/25

6:00 am-8:45 pm

1 stop9h 45m

$329

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 9/1

1:20 pm-9:30 am

1 stop15h 10m

$396

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Mon 8/17

1:25 pm-9:30 am

1 stop15h 05m

$396

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Wed 9/2

2:40 pm-9:30 am

1 stop13h 50m

$399

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Sat 8/29

6:41 am-9:30 am

1 stop21h 49m

$460

Flights are sorted by cheapest round-trip flights first.

Deals found on 8/11

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 12, 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
10,111 reviews

Boarding

7.7

Entertainment

7.1

Food

6.7

Crew

8.1

Overall

7.4

Comfort

7.3

Reviews

1 / 20
4.0
Okay

Chris,Aug 2026

MIA - ORD

Had to go through TSA again, already purchased bottle drink. TSA would not let through, United changed gates last minute. This experience bad for everyone. Staff rude, not our fault. Staff from Chicago to Wichita excellent!
United Airlines
7.4
Good
10,111 reviews
United Airlines
7.4
Good
10,111 reviews

Boarding

7.7

Entertainment

7.1

Food

6.7

Crew

8.1

Overall

7.4

Comfort

7.3

Reviews

1 / 20
4.0
Okay

Chris,Aug 2026

MIA - ORD

Had to go through TSA again, already purchased bottle drink. TSA would not let through, United changed gates last minute. This experience bad for everyone. Staff rude, not our fault. Staff from Chicago to Wichita excellent!

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 18h 40m. Fly via United Airlines 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 $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

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

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 12, 2026.
AirlineCheapestAverageFlexibilityOn-time
United AirlinesCheapest$752Average$1,192FlexibilityNo cancel feeOn-time69%

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.