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Cheap flights from Portland, Maine to London from £254

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 3/4. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — LON
6 Mar — 13 Mar1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from Portland to London

Enter your travel dates to find the best prices.

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 4 February 2026.

Mon 6/405:23
PWM
-
LHR
1 stop20h 22m
Delta
Mon 27/409:55
LHR
-
PWM
2 stops35h 02m
Delta
Deal found 3/2£475
Wed 6/515:39
PWM
-
LHR
1 stop11h 41m
United Airlines
Mon 11/517:50
LHR
-
PWM
2 stops29h 33m
United Airlines
Deal found 3/2£484
Tue 29/917:06
PWM
-
LHR
1 stop11h 14m
United Airlines
Tue 13/1012:05
LHR
-
PWM
2 stops30h 47m
United Airlines
Deal found 3/2£487
Wed 6/506:00
PWM
-
LHR
2 stops19h 30m
Multiple Airlines
Mon 11/517:50
LHR
-
PWM
2 stops32h 29m
Multiple Airlines
Deal found 3/2£494
Mon 24/815:30
PWM
-
LHR
1 stop12h 35m
American Airlines
Fri 11/909:15
LHR
-
PWM
1 stop15h 06m
American Airlines
Deal found 3/2£498
Mon 28/919:22
PWM
-
LHR
1 stop10h 18m
United Airlines
Tue 13/1016:40
LHR
-
PWM
1 stop31h 44m
United Airlines
Deal found 3/2£502
Wed 30/915:15
PWM
-
LHR
2 stops13h 45m
Air Canada
Tue 13/1014:05
LHR
-
PWM
2 stops24h 06m
Air Canada
Deal found 3/2£503
Fri 20/306:00
PWM
-
LHR
1 stop10h 35m
United Airlines
Fri 27/312:50
LHR
-
PWM
1 stop13h 28m
United Airlines
Deal found 3/2£507
Sun 10/509:39
PWM
-
LHR
1 stop18h 21m
United Airlines
Sat 16/506:50
LHR
-
PWM
2 stops16h 33m
United Airlines
Deal found 3/2£513
Tue 7/406:04
PWM
-
LHR
2 stops22h 56m
United Airlines
Mon 27/407:25
LHR
-
PWM
2 stops19h 15m
United Airlines
Deal found 3/2£514
Tue 29/914:35
PWM
-
LGW
2 stops13h 50m
Delta
Tue 13/1010:35
LGW
-
PWM
2 stops18h 14m
Delta
Deal found 3/2£551
Wed 6/514:18
PWM
-
LGW
2 stops27h 07m
Turkish Airlines
Mon 11/517:35
LGW
-
PWM
2 stops35h 01m
Turkish Airlines
Deal found 1/2£611

Find 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 4 February 2026.

Round-trip from

£475

One-way from

£254

Popular in

June

Cheapest in

October

Average price

£492
Delta
  • Delta
  • 6/4-27/4
  • 3 total stops
  • 55h 24m total
  • Portland to London
Search Deals
JetBlue
  • JetBlue
  • 3/4
  • 1 total stop
  • 9h 45m total
  • Portland to London
Search Deals
Highest demand for flights based on searches. 20% potential increase in price (£116 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease (£19 potential savings vs. average return price).
Search Deals
Average for round-trip flights in February 2026
Search Deals

Cheapflights Fare Finder

 
Customise 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 858,174 searches. Data last updated 4 February 2026.
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 6/4

05:23-06:45

1 stop20h 22m

London Heathrow

Mon 27/4

09:55-15:57

2 stops35h 02m

£475

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 8/4

14:30-06:20

1 stop10h 50m

London Heathrow

Mon 27/4

09:55-15:57

2 stops35h 02m

£475

PortlandLondon

PWM - LHR

PWMLHR

Portland

Tue 7/4

12:51-07:10

1 stop13h 19m

London Heathrow

Mon 27/4

09:55-15:57

2 stops35h 02m

£475

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 6/5

15:39-07:15

1 stop10h 36m

London Heathrow

Mon 11/5

17:50-18:23

2 stops29h 33m

£484

PortlandLondon

PWM - LHR

PWMLHR

Portland

Fri 20/3

06:00-20:35

1 stop10h 35m

London Heathrow

Fri 27/3

12:50-22:18

1 stop13h 28m

£507

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sun 10/5

09:39-09:00

1 stop18h 21m

London Heathrow

Sat 16/5

06:50-18:23

2 stops16h 33m

£513

PortlandLondon

PWM - LHR

PWMLHR

Portland

Tue 7/4

06:04-10:00

2 stops22h 56m

London Heathrow

Mon 27/4

07:25-21:40

2 stops19h 15m

£514

PortlandLondon

PWM - LGW

PWMLGW

Portland

Wed 6/5

14:18-22:25

2 stops27h 07m

London Gatwick

Mon 11/5

17:35-23:36

2 stops35h 01m

£611

PortlandLondon

PWM - LCY

PWMLCY

Portland

Tue 7/4

16:48-16:40

2 stops18h 52m

London City

Mon 27/4

09:20-00:46

2 stops20h 26m

£621

PortlandLondon

PWM - LGW

PWMLGW

Portland

Fri 24/4

06:00-06:50

2 stops19h 50m

London Gatwick

Sun 3/5

10:45-23:22

2 stops17h 37m

£635

Flights are sorted by cheapest return flights first.

Deals found on 2/2

Showing 1-10 of 36 results
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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 return 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 £227). Flying from Portland, Maine to London in June is currently the most expensive (average of £410). 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.

How much does it cost for a return flight from Portland, Maine to London?

What’s the top stopover airport for flights from Portland, Maine to London?

Share of one-stop return flights from Portland, Maine to London chosen by Cheapflights users in the past 12 months, using the same stopover each way.

Newark (EWR) – chosen by Cheapflights users on 40% of one-stop itineraries from Portland, Maine to London on Cheapflights.

What’s the cheapest stopover airport for flights from Portland, Maine to London?

Average return fare for one-stop flights from Portland, Maine to London, chosen by Cheapflights users in the past 12 months, with the same stopover each way.

New York (JFK) is the most affordable one-stop option, with an average return flight price of £470.

What’s the fastest stopover option from Portland, Maine to London?

Shortest average travel time for one-stop one-way flights from Portland, Maine to London, based on itineraries clicked by Cheapflights users over the past 12 months, grouped by stopover airport.

Flights via Newark (EWR) have the shortest average one-way travel time for one-stop routes: 9h 40m.

Which airport typically offers the quickest stopover for flights from Portland, Maine to London?

Average stopover duration for one-stop one-way flights from Portland, Maine to London, chosen by Cheapflights users in the last 12 months, grouped by stopover airport.

Flights via Newark (EWR) offer the fastest connection on this route, with an average stopover time of 1h 35m.

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 0 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 36m. Fly via Delta, United Airlines, or Turkish Airlines to get the fastest option. The distance between Portland, Maine and London is about 3173 mi. When browsing for deals, the options you’ll see will be for both direct flights and flights with stops.

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

    The most popular flight routes from Portland, Maine to London are Portland - London Heathrow, Portland - London Gatwick and Portland - London City.

  • 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 holiday 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 £227). Flying from Portland, Maine to London in June is currently the most expensive (average of £410). 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

Travelling to a place near London?

Book flights to London if you plan to visit one of these locations
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Gatwick
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Why should you use Cheapflights to find cheap flight tickets from Portland to London?

Cheapflights helps you find that perfect flight to London from Portland by searching from hundreds of airlines and agencies you know and love. We are also free to use, in case you were wondering!

Can Cheapflights find flights from Portland to London with no change fees?

Certainly. Search results for flights to London from Portland shown to you on Cheapflights can be narrowed down with different useful search filters, which includes flexible booking options.

Can Cheapflights notify me if prices for flights from Portland to London become cheaper?

Yes, Cheapflights offers price alerts on Portland to London flights so you can book your travel at the perfect time. Price Alerts can be enabled by clicking the bell icon next to the flight deals above and providing your email address where you want to receive the alerts.

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