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 9/19. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — LON
Oct 11 — Oct 181
Sat 10/11
Sat 10/18
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.

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 September 11, 2025.

Round-trip from

$524
(Delta)

One-way from

$349
(Expedia)

Popular in

July

Cheapest in

October

Average price

$790
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 ($186 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease ($30 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in September 2025
Search Deals

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 September 11, 2025.

This Delta deal was found by Cheapflights users on 9/11. 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.
Mon 11/101:25 pmPWM - LHR
1 stop13h 25mDelta
Tue 11/188:55 amLHR - PWM
2 stops19h 59mDelta
Deal found 9/11$524
This Delta deal was found by Cheapflights users on 9/11. 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.
Wed 10/82:38 pmPWM - LHR
1 stop15h 47mDelta
Wed 10/159:00 amLHR - PWM
2 stops20h 05mDelta
Deal found 9/11$525
This Delta deal was found by Cheapflights users on 9/11. 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.
Sat 11/82:38 pmPWM - LHR
1 stop24h 32mDelta
Tue 11/1811:45 amLHR - PWM
2 stops17h 09mDelta
Deal found 9/11$526
This Delta deal was found by Cheapflights users on 9/9. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/262:41 pmPWM - LHR
1 stop14h 19mDelta
Fri 10/1011:45 amLHR - PWM
2 stops17h 20mDelta
Deal found 9/9$574
This Delta deal was found by Cheapflights users on 9/9. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/32:41 pmPWM - LHR
1 stop14h 19mDelta
Fri 10/1011:45 amLHR - PWM
2 stops17h 20mDelta
Deal found 9/9$575
This KLM deal was found by Cheapflights users on 9/11. 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 KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/32:41 pmPWM - LHR
1 stop13h 09mKLM
Fri 10/104:05 pmLHR - PWM
1 stop13h 00mKLM
Deal found 9/11$582
This Delta deal was found by Cheapflights users on 9/10. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/142:30 pmPWM - LCY
2 stops14h 00mDelta
Tue 11/1810:00 amLCY - PWM
2 stops18h 54mDelta
Deal found 9/10$632
This United Airlines deal was found by Cheapflights users on 9/11. 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.
Sun 11/93:00 pmPWM - LCY
2 stops16h 50mMultiple Airlines
Mon 11/177:10 pmLCY - PWM
2 stops28h 49mMultiple Airlines
Deal found 9/11$778
This United Airlines deal was found by Cheapflights users on 9/11. 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.
Thu 11/132:20 pmPWM - LCY
2 stops14h 00mMultiple Airlines
Tue 11/185:45 pmLCY - PWM
2 stops29h 03mMultiple Airlines
Deal found 9/11$834
This FlightHub deal was found by Cheapflights users on 9/9. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/267:09 amPWM - LGW
2 stops21h 46mTurkish Airlines
Fri 10/105:15 pmLGW - PWM
2 stops34h 49mTurkish Airlines
Deal found 9/9$1,014
This Kiwi.com deal was found by Cheapflights users on 9/9. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/39:46 amPWM - LGW
1 stop19h 14mMultiple Airlines
Fri 10/102:00 pmLGW - PWM
1 stop25h 36mMultiple Airlines
Deal found 9/9$1,016
This KAYAK deal was found by Cheapflights users on 9/9. 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/32:17 pmPWM - LGW
2 stops20h 58mTurkish Airlines
Fri 10/105:15 pmLGW - PWM
2 stops34h 49mTurkish Airlines
Deal found 9/9$1,029

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 September 11, 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

Mon 11/10

1:25 pm-7:50 am

1 stop13h 25m

London Heathrow

Tue 11/18

8:55 am-11:54 pm

2 stops19h 59m

$524

PortlandLondon

PWM - LHR

PWMLHR

Portland

Mon 11/10

1:25 pm-6:25 am

1 stop12h 00m

London Heathrow

Wed 11/19

8:55 am-11:54 pm

2 stops19h 59m

$525

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sun 11/9

4:53 pm-8:45 am

1 stop10h 52m

London Heathrow

Wed 11/19

9:00 am-11:54 pm

2 stops19h 54m

$525

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sat 11/8

2:38 pm-8:10 pm

1 stop24h 32m

London Heathrow

Wed 11/19

8:55 am-11:54 pm

2 stops19h 59m

$525

PortlandLondon

PWM - LHR

PWMLHR

Portland

Fri 9/26

2:41 pm-10:00 am

1 stop14h 19m

London Heathrow

Fri 10/10

11:45 am-12:05 am

2 stops17h 20m

$574

PortlandLondon

PWM - LHR

PWMLHR

Portland

Fri 10/3

2:41 pm-10:00 am

1 stop14h 19m

London Heathrow

Fri 10/10

11:45 am-12:05 am

2 stops17h 20m

$575

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sun 10/26

11:41 am-7:05 am

1 stop15h 24m

London Heathrow

Sun 11/2

11:30 am-12:05 am

2 stops17h 35m

$614

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sun 10/26

6:00 am-9:00 am

1 stop23h 00m

London Heathrow

Sun 11/2

10:45 am-10:19 pm

1 stop16h 34m

$622

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sat 11/8

2:38 pm-8:10 pm

1 stop24h 32m

London Heathrow

Sun 11/16

4:35 pm-11:54 pm

1 stop12h 19m

$622

PortlandLondon

PWM - LCY

PWMLCY

Portland

Fri 11/14

6:35 am-9:30 am

2 stops21h 55m

London City

Tue 11/18

9:20 am-11:54 pm

2 stops43h 34m

$632

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/11

Showing 1-10 of 32 results
1
2
3
4

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, November is the cheapest month in which you can book a flight from Portland, Maine to London (average of $661). Flying from Portland, Maine to London in June is currently the most expensive (average of $1,098). 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 September 11, 2025.

Unlike in the afternoon, when flights are generally more expensive, you can save up to 5% on flights from Portland, Maine to London by exploring options for tickets at noon.

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 September 11, 2025.
Get a feel of what it's like to fly with Delta, United Airlines, and American Airlines 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
8.0
Very good
7,960 reviews

Boarding

8.2

Overall

8.0

Entertainment

7.9

Food

7.3

Crew

8.5

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
Delta
8.0
Very good
7,960 reviews
Delta
8.0
Very good
7,960 reviews

Boarding

8.2

Overall

8.0

Entertainment

7.9

Food

7.3

Crew

8.5

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
United Airlines
7.4
Good
8,937 reviews
Delta
8.0
Very good
7,960 reviews

Boarding

8.2

Overall

8.0

Entertainment

7.9

Food

7.3

Crew

8.5

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
American Airlines
7.2
Good
10,000 reviews
Delta
8.0
Very good
7,960 reviews

Boarding

8.2

Overall

8.0

Entertainment

7.9

Food

7.3

Crew

8.5

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!
JetBlue
7.2
Good
2,913 reviews
Delta
8.0
Very good
7,960 reviews

Boarding

8.2

Overall

8.0

Entertainment

7.9

Food

7.3

Crew

8.5

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

Kim,May 2025

PIH - SLC

This trip was fine even with delay I had plenty of time to get connection flight!

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 3 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 13h 25m. Fly via Delta or Turkish 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 JetBlue is currently your cheapest option to London, with prices starting at $586. Additional round-trip tickets that might be worth considering are offered by United Airlines and Delta, with the lowest prices starting at $648 and $825, respectively. JetBlue is 32% 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. Scandinavian Airlines flights start at $457 while deals on Air Canada start at $1,199 one-way.

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

    Most travelers choose Portland - London City, Portland - London Gatwick or Portland - London Heathrow 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, November is the cheapest month in which you can book a flight from Portland, Maine to London (average of $661). Flying from Portland, Maine to London in June is currently the most expensive (average of $1,098). 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
Hayes
Thornton Heath
Southend-on-Sea
Harrow
Canterbury
Croydon
Eastleigh
Dartford
Dover
Winchester
Orpington
Gatwick
Borehamwood
Aylesbury
Bedford
Wembley
Folkestone
Chichester
Arundel

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 3 airlines flying from Portland to London

Discover the top 3 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 September 11, 2025.
AirlineCheapestAverageFlexibilityOn-time
JetBlueCheapest$586Average$678FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$648Average$853FlexibilityNo cancel feeOn-time69%
DeltaCheapest$825Average$1,083FlexibilityNo 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.