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Cheap flights from Portland, Maine to London from £189

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 7/5. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — LON
17 May — 24 May1
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 17 April 2026.

Wed 6/514:51
PWM
-
LHR
1 stop10h 29m
Delta
Mon 11/509:55
LHR
-
PWM
2 stops18h 14m
Delta
Deal found 16/4£538
Tue 10/1110:00
PWM
-
LHR
1 stop17h 05m
Delta
Tue 17/1108:40
LHR
-
PWM
2 stops20h 09m
Delta
Deal found 17/4£539
Wed 6/514:51
PWM
-
LHR
1 stop14h 29m
KLM
Mon 11/509:20
LHR
-
PWM
1 stop18h 49m
KLM
Deal found 16/4£543
Tue 10/1114:35
PWM
-
LHR
1 stop14h 40m
KLM
Tue 24/1108:55
LHR
-
PWM
1 stop18h 28m
KLM
Deal found 17/4£544
Tue 10/1113:35
PWM
-
LHR
1 stop13h 15m
Delta
Tue 24/1108:40
LHR
-
PWM
2 stops18h 43m
Delta
Deal found 16/4£550
Thu 7/514:38
PWM
-
LHR
1 stop10h 42m
Delta
Sun 10/511:30
LHR
-
PWM
2 stops18h 13m
Delta
Deal found 16/4£551
Sun 10/514:38
PWM
-
LHR
1 stop14h 42m
Delta
Sat 16/506:30
LHR
-
PWM
2 stops23h 13m
Delta
Deal found 15/4£551
Fri 8/514:38
PWM
-
LHR
1 stop10h 42m
Delta
Sun 10/509:20
LHR
-
PWM
1 stop18h 49m
Delta
Deal found 15/4£554
Fri 8/514:38
PWM
-
LGW
2 stops13h 47m
Delta
Sun 10/510:25
LGW
-
PWM
2 stops19h 18m
Delta
Deal found 15/4£564
Thu 7/516:48
PWM
-
LGW
2 stops18h 12m
Delta
Sun 10/510:25
LGW
-
PWM
2 stops19h 18m
Delta
Deal found 16/4£565
Tue 22/914:35
PWM
-
LGW
2 stops13h 50m
Delta
Sun 4/1010:25
LGW
-
PWM
2 stops18h 34m
Delta
Deal found 13/4£569
Thu 14/514:38
PWM
-
LGW
2 stops13h 47m
Delta
Thu 21/510:25
LGW
-
PWM
2 stops19h 18m
Delta
Deal found 14/4£586

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 17 April 2026.

Round-trip from

£538

One-way from

£189

Popular in

July

Cheapest in

October

Average price

£632
Delta
  • Delta
  • 6/5-11/5
  • 3 total stops
  • 28h 43m total
  • Portland to London
Search Deals
KLM
  • KLM
  • 7/5
  • 1 total stop
  • 13h 12m total
  • Portland to London
Search Deals
Highest demand for flights based on searches. 23% potential increase in price (£139 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 10% potential price decrease (£45 potential savings vs. average return price).
Search Deals
Average for round-trip flights in April 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 17 April 2026.
Use the filters below to find and compare flights from Portland to London that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest return flight

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 6/5

14:51-06:20

1 stop10h 29m

London Heathrow

Mon 11/5

09:55-23:09

2 stops18h 14m

£538
Fastest return journey

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 7/5

14:38-08:50

1 stop13h 12m

London Heathrow

Thu 14/5

15:50-00:43

1 stop13h 53m

£543

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sun 16/8

06:30-06:20

1 stop18h 50m

London Heathrow

Sat 22/8

11:15-22:33

1 stop16h 18m

£543

PortlandLondon

PWM - LHR

PWMLHR

Portland

Mon 10/8

06:00-07:15

1 stop20h 15m

London Heathrow

Wed 19/8

11:15-22:33

1 stop16h 18m

£544

PortlandLondon

PWM - LHR

PWMLHR

Portland

Fri 8/5

14:38-12:05

1 stop16h 27m

London Heathrow

Wed 13/5

06:30-23:12

2 stops21h 42m

£549

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 6/5

14:51-10:20

1 stop14h 29m

London Heathrow

Mon 11/5

11:45-00:43

1 stop17h 58m

£554

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sun 10/5

14:38-08:50

1 stop13h 12m

London Heathrow

Sat 16/5

12:50-00:43

1 stop16h 53m

£556

PortlandLondon

PWM - LGW

PWMLGW

Portland

Fri 8/5

14:38-09:25

2 stops13h 47m

London Gatwick

Sun 10/5

10:25-00:43

2 stops19h 18m

£564

PortlandLondon

PWM - LGW

PWMLGW

Portland

Thu 7/5

16:48-16:00

2 stops18h 12m

London Gatwick

Sun 10/5

10:25-00:43

2 stops19h 18m

£565

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 6/5

05:21-06:25

1 stop20h 04m

London Heathrow

Mon 1/6

06:15-23:09

2 stops21h 54m

£568

Flights are sorted by cheapest return flights first.

Deals found on 15/4

Showing 1-10 of 52 resultsSorted by cheapest first
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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

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.

New York (JFK) – chosen by Cheapflights users on 50% 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 £474.

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 24m.

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 29m. Fly via Delta, KLM, or Virgin Atlantic 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.

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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Croydon
Hounslow
Luton
Gatwick
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Ilford
Hayes
Brentford
Colchester
Watford
Kingston upon Thames
Romford
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Ipswich
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How does Cheapflights help users find flights from Portland to London?

Cheapflights helps you search for flights from Portland to London via 900+ travel sites so you don’t have to. After performing a flight search, users can also filter their flight selection by filtering for price, number of stops, airlines, and so on.

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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