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$326+ Cheap flights from Portland, ME (PWM) to London (LON)

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 — LON
Dec 19 — Dec 261
Fri 12/19
Fri 12/26
1 adult, Economy
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Find flight deals from Portland to London

Cheapest flights from Portland to London
Explore the most affordable flight options available from Portland to London. Find the lowest fares from popular airlines and budget airlines, with prices last updated on November 19, 2025.

This Delta deal was found by Cheapflights users on 11/18. 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 12/104:53 pmPWM - LHR
1 stop10h 52mDelta
Fri 12/1912:40 pmLHR - PWM
1 stop15h 41mDelta
Deal found 11/18$847
This Delta deal was found by Cheapflights users on 11/18. 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 12/116:08 amPWM - LHR
2 stops19h 57mDelta
Thu 12/188:55 amLHR - PWM
1 stop20h 04mDelta
Deal found 11/18$852
This Delta deal was found by Cheapflights users on 11/18. 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 12/102:34 pmPWM - LHR
1 stop10h 46mDelta
Wed 12/172:45 pmLHR - PWM
2 stops28h 09mDelta
Deal found 11/18$880
This KLM deal was found by Cheapflights users on 11/18. 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 12/104:53 pmPWM - LHR
1 stop10h 52mKLM
Wed 12/1710:10 amLHR - PWM
1 stop18h 54mKLM
Deal found 11/18$897
This Air France deal was found by Cheapflights users on 11/18. 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 France is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/1112:53 pmPWM - LHR
1 stop14h 52mAir France
Wed 12/1710:10 amLHR - PWM
1 stop18h 54mAir France
Deal found 11/18$957
This United Airlines deal was found by Cheapflights users on 11/18. 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.
Thu 12/116:00 amPWM - LHR
3 stops20h 10mUnited Airlines
Thu 12/184:20 pmLHR - PWM
1 stop12h 39mUnited Airlines
Deal found 11/18$996
This United Airlines deal was found by Cheapflights users on 11/18. 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 12/167:46 pmPWM - LHR
1 stop10h 19mUnited Airlines
Tue 12/234:00 pmLHR - PWM
1 stop12h 22mUnited Airlines
Deal found 11/18$1,015
This KAYAK deal was found by Cheapflights users on 11/18. 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/1210:35 amPWM - LHR
1 stop29h 45mAustrian Airlines
Wed 12/179:10 amLHR - PWM
1 stop14h 33mAustrian Airlines
Deal found 11/18$1,023
This Delta deal was found by Cheapflights users on 11/18. 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 12/126:15 amPWM - LHR
1 stop19h 40mDelta
Fri 12/1912:40 pmLHR - PWM
2 stops28h 36mDelta
Deal found 11/18$1,032
This Travelocity deal was found by Cheapflights users on 11/18. 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 Travelocity is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/1610:35 amPWM - LHR
1 stop18h 50mMultiple Airlines
Tue 12/231:25 pmLHR - PWM
2 stops34h 01mMultiple Airlines
Deal found 11/18$1,038
This Air Canada deal was found by Cheapflights users on 11/18. 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 12/106:00 amPWM - LHR
2 stops20h 10mAir Canada
Fri 12/191:25 pmLHR - PWM
2 stops38h 57mAir Canada
Deal found 11/18$1,111
This American Airlines deal was found by Cheapflights users on 11/18. 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.
Tue 12/166:40 pmPWM - LCY
2 stops13h 00mMultiple Airlines
Tue 12/236:50 amLCY - PWM
2 stops16h 26mMultiple Airlines
Deal found 11/18$1,685

Cheap flight deals from Portland to London

Discover tips and strategies to find the most affordable flight options for your journey from Portland (PWM) to London (LON). 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 19, 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

$850
Provider with most accurate pricing for Portland-London (LON) flight deals.
Search Deals
Provider most trusted by Cheapflights users for Portland-London (LON) flights.
Search Deals
From Portland to London (LON)
Search Deals
One-way flight from Portland to London (LON)
Search Deals
Highest demand for flights based on searches. 17% potential increase in price ($184 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease ($34 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in November 2025
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Portland to London 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 19, 2025.
Use the filters below to find and compare flights from Portland to London that are best for you.

Fly from

Portland

Fly to

London

Route

Depart

Return

Price

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sat 2/7

12:48 pm-9:00 am

2 stops15h 12m

London Heathrow

Sat 2/14

8:55 am-11:04 pm

1 stop19h 09m

$658

PortlandLondon

PWM - LCY

PWMLCY

Portland

Fri 1/23

2:35 pm-9:30 am

2 stops13h 55m

London City

Tue 1/27

8:40 am-10:27 pm

2 stops18h 47m

$661

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

$741

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 1/1

1:03 pm-6:20 am

1 stop12h 17m

London Heathrow

Sun 1/11

8:55 am-12:20 am

1 stop20h 25m

$753

PortlandLondon

PWM - LHR

PWMLHR

Portland

Fri 3/27

2:35 pm-9:20 am

2 stops14h 45m

London Heathrow

Tue 3/31

10:35 am-11:49 pm

2 stops42h 14m

$845

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 1/1

1:03 pm-6:20 am

1 stop12h 17m

London Heathrow

Thu 1/8

8:55 am-10:27 pm

1 stop18h 32m

$845

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 12/11

12:53 pm-8:45 am

1 stop14h 52m

London Heathrow

Thu 12/18

10:10 am-11:59 pm

1 stop18h 49m

$847

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 12/10

2:34 pm-10:15 am

1 stop14h 41m

London Heathrow

Thu 12/18

10:45 am-10:23 pm

1 stop16h 38m

$847

PortlandLondon

PWM - LHR

PWMLHR

Portland

Fri 12/12

2:34 pm-6:55 am

1 stop11h 21m

London Heathrow

Thu 12/18

4:35 pm-11:59 pm

1 stop12h 24m

$847

PortlandLondon

PWM - LHR

PWMLHR

Portland

Fri 12/12

6:08 am-7:50 am

1 stop20h 42m

London Heathrow

Fri 12/19

8:00 pm-12:20 pm

1 stop21h 20m

$847

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/16

Showing 1-10 of 23 results
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Compare providers for flights from Portland to London

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 London in November.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy2 starsTrust Score*3 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*1 star
AranGrantPrice Accuracy2 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 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 flight deals on Cheapflights vs. eDreams >95% of the time. Price accuracy is based on data collected from Portland, Maine-London flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Portland, Maine-London 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 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 London

Have a flexible travel schedule? Discover the best time to fly to London 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

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

Currently, August is the cheapest month in which you can book a flight from Portland, Maine to London (average of $311). Flying from Portland, Maine to London in June is currently the most expensive (average of $561). 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 LON?

Find hourly flight availability from Portland to London. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated November 19, 2025.

Unlike at noon, when flights are generally more expensive, you can save up to 31% on flights from Portland, Maine to London by exploring options for tickets in the afternoon.

Reviews of airlines servicing London

Get insights into the airlines that provide service to London. 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 London. Reviews last updated November 19, 2025.
Get a feel of what it's like to fly with Delta, United Airlines, and JetBlue from Portland to London by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
7.9
Good
8,002 reviews

Entertainment

7.9

Food

7.3

Overall

7.9

Crew

8.5

Comfort

7.9

Boarding

8.1

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
8,002 reviews
Delta
7.9
Good
8,002 reviews

Entertainment

7.9

Food

7.3

Overall

7.9

Crew

8.5

Comfort

7.9

Boarding

8.1

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
9,020 reviews
Delta
7.9
Good
8,002 reviews

Entertainment

7.9

Food

7.3

Overall

7.9

Crew

8.5

Comfort

7.9

Boarding

8.1

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.
JetBlue
7.2
Good
2,902 reviews
Delta
7.9
Good
8,002 reviews

Entertainment

7.9

Food

7.3

Overall

7.9

Crew

8.5

Comfort

7.9

Boarding

8.1

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 London. 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?

    Portland (PWM) is the airport you will fly out of if you book a flight from Portland to London. You should not have trouble finding flights to London from Portland; the airport handles an average of 0 outbound flights to London per day. You should also have plenty of airline options to choose from since 2 airlines have flights from the Portland airport to London. 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?

    There are many flights that can get you from Portland, Maine to London in 9h 45m. Fly via Delta, JetBlue, or Scandinavian Airlines to get the fastest option. There are 3173 mi between Portland, Maine and London. This flight may include one or multiple stops.

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

    Flying on United Airlines is currently your cheapest option to London, with prices starting at $648. Another option worth looking into is Delta, starting at $825 round trip. United Airlines is 25% cheaper than the average price of flights available within the next 90 days to this destination.

  • What are the most popular routes from Portland, Maine to London?

    Most travelers choose Portland - London Heathrow, Portland - London Gatwick or Portland - London City when deciding on the best route from Portland, Maine to London.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Portland to London 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?

    Currently, August is the cheapest month in which you can book a flight from Portland, Maine to London (average of $311). Flying from Portland, Maine to London in June is currently the most expensive (average of $561). 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?

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

Browse thousands of different options on Cheapflights for your next trip

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Top 2 airlines flying from Portland to London

Discover the top 2 airlines that operate flights from Portland to London. 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 19, 2025.
AirlineCheapestAverageFlexibilityOn-time
United AirlinesCheapest$648Average$924FlexibilityNo cancel feeOn-time69%
DeltaCheapest$825Average$963FlexibilityNo cancel feeOn-timeN/A

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