HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
London

$349+ 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 4/19. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — LON
Dec 6 — Dec 131
Sat 12/6
Sat 12/13
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Portland to London 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.

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 6, 2025.

This Netflights deal was found by Cheapflights users on 11/4. 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 Netflights is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/46:08 amPWM - LHR
1 stop20h 42mVirgin Atlantic
Thu 12/118:55 amLHR - PWM
1 stop18h 28mVirgin Atlantic
Deal found 11/4$583
This Delta deal was found by Cheapflights users on 11/4. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/44:53 pmPWM - LHR
1 stop10h 52mDelta
Thu 12/118:55 amLHR - PWM
2 stops20h 04mDelta
Deal found 11/4$614
This Justfly.com deal was found by Cheapflights users on 11/4. 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 Justfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/44:53 pmPWM - LHR
1 stop10h 52mMultiple Airlines
Thu 12/1110:45 amLHR - PWM
1 stop16h 38mMultiple Airlines
Deal found 11/4$653
This Justfly.com deal was found by Cheapflights users on 11/4. 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 Justfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/42:34 pmPWM - LHR
2 stops13h 26mKLM
Thu 12/1111:45 amLHR - PWM
2 stops17h 14mKLM
Deal found 11/4$683
This Delta deal was found by Cheapflights users on 11/6. 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.
Sat 11/81:27 pmPWM - LHR
1 stop11h 58mDelta
Sat 11/158:55 amLHR - PWM
2 stops19h 59mDelta
Deal found 11/6$689
This Expedia deal was found by Cheapflights users on 11/4. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/46:15 amPWM - LCY
2 stops21h 35mKLM
Thu 12/119:20 amLCY - PWM
2 stops19h 39mKLM
Deal found 11/4$695
This KLM deal was found by Cheapflights users on 11/6. 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 KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/82:38 pmPWM - LHR
1 stop12h 27mKLM
Sat 11/1512:40 pmLHR - PWM
1 stop16h 14mKLM
Deal found 11/6$696
This KLM deal was found by Cheapflights users on 11/4. 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.
Fri 11/71:27 pmPWM - LHR
1 stop14h 33mKLM
Sun 11/168:55 amLHR - PWM
1 stop18h 24mKLM
Deal found 11/4$697
This Delta deal was found by Cheapflights users on 11/4. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/712:45 pmPWM - LHR
2 stops17h 55mDelta
Sun 11/163:50 pmLHR - PWM
2 stops25h 18mDelta
Deal found 11/4$701
This Scandinavian Airlines deal was found by Cheapflights users on 11/4. 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 Scandinavian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/46:15 amPWM - LHR
2 stops22h 05mScandinavian Airlines
Thu 12/116:40 amLHR - PWM
3 stops22h 19mScandinavian Airlines
Deal found 11/4$716
This United Airlines deal was found by Cheapflights users on 11/4. 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.
Thu 12/410:02 amPWM - LCY
2 stops18h 18mMultiple Airlines
Thu 12/115:40 pmLCY - PWM
2 stops30h 14mMultiple Airlines
Deal found 11/4$752
This Delta deal was found by Cheapflights users on 11/4. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/72:38 pmPWM - LCY
2 stops13h 52mDelta
Tue 11/118:40 amLCY - PWM
2 stops44h 14mDelta
Deal found 11/4$812

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 6, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$583
(Netflights)

One-way from

$349
(JetBlue)

Popular in

June

Cheapest in

October

Average price

$790
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 ($181 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease ($32 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 6, 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

Thu 12/4

4:53 pm-8:45 am

1 stop10h 52m

London Heathrow

Thu 12/11

8:55 am-11:59 pm

2 stops20h 04m

$614

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 1/14

12:20 pm-8:45 am

1 stop15h 25m

London Heathrow

Mon 1/19

4:35 pm-12:20 am

1 stop12h 45m

$630

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 12/4

2:34 pm-9:00 am

2 stops13h 26m

London Heathrow

Thu 12/11

12:30 pm-10:23 pm

1 stop14h 53m

$663

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 12/4

2:34 pm-9:00 am

2 stops13h 26m

London Heathrow

Thu 12/11

11:45 am-11:59 pm

2 stops17h 14m

$683

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 1/14

8:40 am-7:10 am

3 stops17h 30m

London Heathrow

Mon 1/19

6:00 pm-1:56 pm

2 stops24h 56m

$695

PortlandLondon

PWM - LCY

PWMLCY

Portland

Thu 12/4

6:15 am-8:50 am

2 stops21h 35m

London City

Thu 12/11

9:20 am-11:59 pm

2 stops19h 39m

$695

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 12/4

6:15 am-9:20 am

2 stops22h 05m

London Heathrow

Thu 12/11

6:40 am-11:59 pm

3 stops22h 19m

$716

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 3/18

11:17 am-9:20 am

2 stops18h 03m

London Heathrow

Wed 3/25

6:50 am-6:13 pm

2 stops15h 23m

$725

PortlandLondon

PWM - LHR

PWMLHR

Portland

Mon 4/20

2:20 pm-9:30 am

1 stop14h 10m

London Heathrow

Thu 4/23

11:55 am-11:36 pm

1 stop16h 41m

$747

PortlandLondon

PWM - LCY

PWMLCY

Portland

Thu 12/4

10:02 am-9:20 am

2 stops18h 18m

London City

Thu 12/11

5:40 pm-6:54 pm

2 stops30h 14m

$752

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/6

Showing 1-10 of 54 results
1
2
3
...
6

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 6, 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.

How much does it cost to fly round-trip from Portland, Maine to London?

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 6, 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
8,001 reviews

Crew

8.5

Food

7.3

Entertainment

7.9

Boarding

8.2

Comfort

7.9

Overall

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
8,001 reviews
Delta
7.9
Good
8,001 reviews

Crew

8.5

Food

7.3

Entertainment

7.9

Boarding

8.2

Comfort

7.9

Overall

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
9,003 reviews
Delta
7.9
Good
8,001 reviews

Crew

8.5

Food

7.3

Entertainment

7.9

Boarding

8.2

Comfort

7.9

Overall

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.
JetBlue
7.2
Good
2,907 reviews
Delta
7.9
Good
8,001 reviews

Crew

8.5

Food

7.3

Entertainment

7.9

Boarding

8.2

Comfort

7.9

Overall

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 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 10h 52m. Fly via Delta or KLM 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 24% cheaper than the average price of flights available within the next 90 days to this destination.

  • What are the cheapest airlines to fly from Portland, Maine to London one-way?

    To fly one-way, consider booking your trip with JetBlue, which is currently one of the cheapest options available, starting at $349. United Airlines flights start at $399 while deals on Delta start at $406 one-way.

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

    Most travelers choose Portland - London Heathrow, Portland - London City or Portland - London Gatwick 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

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

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 6, 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.