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Cheap flights from Portland, Maine to London from £253

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 23/7. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — LON
25 Jun — 2 Jul1
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 26 May 2026.

Wed 11/1115:15
PWM
-
LHR
1 stop14h 10m
United Airlines
Fri 13/1106:50
LHR
-
PWM
2 stops16h 23m
United Airlines
Deal found 25/5£562
Wed 11/1111:17
PWM
-
LHR
3 stops19h 03m
Air Canada
Fri 13/1109:00
LHR
-
PWM
3 stops18h 57m
Air Canada
Deal found 25/5£582
Fri 11/906:30
PWM
-
LHR
2 stops22h 05m
Scandinavian Airlines
Thu 17/919:50
LHR
-
PWM
2 stops33h 09m
Scandinavian Airlines
Deal found 25/5£595
Wed 11/1111:17
PWM
-
LHR
1 stop14h 03m
Multiple Airlines
Fri 13/1107:25
LHR
-
PWM
1 stop21h 18m
Multiple Airlines
Deal found 25/5£634
Thu 1/1014:35
PWM
-
LHR
2 stops22h 55m
Scandinavian Airlines
Thu 8/1007:05
LHR
-
PWM
2 stops21h 44m
Scandinavian Airlines
Deal found 25/5£640
Fri 11/918:53
PWM
-
LHR
2 stops45h 07m
Multiple Airlines
Thu 17/908:15
LHR
-
PWM
1 stop20h 37m
Multiple Airlines
Deal found 25/5£642
Tue 10/1106:30
PWM
-
LHR
1 stop18h 50m
Delta
Tue 17/1106:30
LHR
-
PWM
2 stops20h 53m
Delta
Deal found 21/5£642
Tue 1/916:47
PWM
-
LHR
2 stops15h 28m
Delta
Sat 12/908:40
LHR
-
PWM
2 stops20h 19m
Delta
Deal found 23/5£647
Tue 17/1110:00
PWM
-
LGW
2 stops18h 00m
Delta
Sat 21/1110:00
LGW
-
PWM
2 stops18h 49m
Delta
Deal found 21/5£651
Thu 15/1014:35
PWM
-
LGW
2 stops13h 50m
Delta
Tue 20/1010:35
LGW
-
PWM
2 stops18h 14m
Delta
Deal found 23/5£651
Tue 10/1111:17
PWM
-
LHR
1 stop18h 08m
Austrian Airlines
Tue 17/1109:10
LHR
-
PWM
1 stop14h 03m
Austrian Airlines
Deal found 25/5£655
Tue 1/911:50
PWM
-
LGW
2 stops16h 35m
Delta
Sat 12/910:25
LGW
-
PWM
2 stops17h 08m
Delta
Deal found 23/5£731

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 26 May 2026.

Round-trip from

£562

One-way from

£253

Popular in

July

Cheapest in

October

Average price

£542
United Airlines
  • United Airlines
  • 11/11-13/11
  • 3 total stops
  • 30h 33m total
  • Portland to London
Search Deals
Delta
  • Delta
  • 23/7
  • 2 total stops
  • 15h 10m total
  • Portland to London
Search Deals
Highest demand for flights based on searches. 22% potential increase in price (£131 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 6% potential price decrease (£30 potential savings vs. average return price).
Search Deals
Average for round-trip flights in May 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 26 May 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 11/11

15:15-10:25

1 stop14h 10m

London Heathrow

Fri 13/11

06:50-18:13

2 stops16h 23m

£562

PortlandLondon

PWM - LHR

PWMLHR

Portland

Tue 10/11

06:00-06:25

1 stop19h 25m

London Heathrow

Tue 24/11

08:40-22:23

2 stops18h 43m

£642

PortlandLondon

PWM - LHR

PWMLHR

Portland

Tue 17/11

06:00-06:25

1 stop19h 25m

London Heathrow

Sat 21/11

06:30-22:23

2 stops20h 53m

£642

PortlandLondon

PWM - LHR

PWMLHR

Portland

Tue 10/11

14:35-08:05

1 stop12h 30m

London Heathrow

Tue 17/11

06:30-22:23

2 stops20h 53m

£642

PortlandLondon

PWM - LGW

PWMLGW

Portland

Tue 17/11

10:00-09:00

2 stops18h 00m

London Gatwick

Sat 21/11

10:00-23:49

2 stops18h 49m

£651

PortlandLondon

PWM - LGW

PWMLGW

Portland

Thu 15/10

14:35-09:25

2 stops13h 50m

London Gatwick

Tue 20/10

10:35-23:49

2 stops18h 14m

£651

PortlandLondon

PWM - LGW

PWMLGW

Portland

Thu 15/10

06:00-16:35

2 stops29h 35m

London Gatwick

Tue 20/10

07:00-23:52

2 stops21h 52m

£768

PortlandLondon

PWM - LGW

PWMLGW

Portland

Sun 8/11

06:30-15:45

2 stops28h 15m

London Gatwick

Mon 16/11

10:40-23:43

2 stops18h 03m

£786

PortlandLondon

PWM - LGW

PWMLGW

Portland

Fri 11/9

15:40-14:40

2 stops18h 00m

London Gatwick

Thu 17/9

15:40-22:25

2 stops35h 45m

£846

PortlandLondon

PWM - LGW

PWMLGW

Portland

Thu 18/6

07:58-06:50

2 stops17h 52m

London Gatwick

Thu 25/6

14:30-14:24

2 stops28h 54m

£853

Flights are sorted by cheapest return flights first.

Deals found on 22/5

Showing 1-10 of 49 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.

Newark (EWR) – chosen by Cheapflights users on 33% 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 £426.

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 14h 10m. Fly via United Airlines, Delta, 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.

See more FAQs

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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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