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Cheap flights from Portland, Maine to London from £244

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Portland, Maine to London departing on 1/9. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
1 adult, Economy, 0 bags

Find the cheapest flights from Portland, Maine to London

Cheap return flights

Enter your travel dates to find the best prices.
United Airlines Logo
08:45 - 08:25PWM  Portland-LHR London Heathrow
18h 40m1 stop Newark
United Airlines Logo
06:50 - 23:21LHR  London Heathrow-PWM Portland
21h 31m2 stops Brussels Bruxelles-National Newark
£548United Airlines
Mon, 9 Nov - Wed, 11 Nov
Multiple Airlines Logo
17:09 - 10:00PWM  Portland-LGW London Gatwick
35h 51m2 stops Raleigh-Durham Orlando
Multiple Airlines Logo
10:10 - 09:08LGW  London Gatwick-PWM Portland
26h 58m1 stop Orlando
£565Multiple Airlines
Wed, 21 Oct - Tue, 27 Oct
United Airlines Logo
15:41 - 10:05PWM  Portland-LHR London Heathrow
13h 24m2 stops Newark Brussels Bruxelles-National
United Airlines Logo
09:10 - 21:51LHR  London Heathrow-PWM Portland
17h 41m2 stops Newark Chicago O'Hare Intl
£568United Airlines
Mon, 9 Nov - Wed, 11 Nov
Multiple Airlines Logo
09:48 - 10:00PWM  Portland-LGW London Gatwick
19h 12m1 stop Orlando
Multiple Airlines Logo
10:10 - 09:08LGW  London Gatwick-PWM Portland
26h 58m1 stop Orlando
£611Multiple Airlines
Wed, 21 Oct - Tue, 27 Oct
Multiple Airlines Logo
07:00 - 10:00PWM  Portland-LGW London Gatwick
22h 00m2 stops Cincinnati Cinci./N. Kentucky Orlando
Multiple Airlines Logo
14:00 - 09:08LGW  London Gatwick-PWM Portland
24h 08m1 stop Orlando
£637Multiple Airlines
Mon, 19 Oct - Fri, 23 Oct
Multiple Airlines Logo
09:48 - 10:00PWM  Portland-LGW London Gatwick
19h 12m1 stop Orlando
Multiple Airlines Logo
14:00 - 09:08LGW  London Gatwick-PWM Portland
24h 08m1 stop Orlando
£639Multiple Airlines
Mon, 19 Oct - Fri, 23 Oct
United Airlines Logo
14:05 - 06:40PWM  Portland-LHR London Heathrow
11h 35m1 stop Washington, D.C. Dulles Intl
United Airlines Logo
06:50 - 19:02LHR  London Heathrow-PWM Portland
17h 12m2 stops Brussels Bruxelles-National Washington, D.C. Dulles Intl
£641United Airlines
Tue, 10 Nov - Tue, 24 Nov
Delta Logo
16:03 - 10:30PWM  Portland-LHR London Heathrow
13h 27m1 stop New York John F Kennedy Intl
Delta Logo
10:00 - 23:55LHR  London Heathrow-PWM Portland
18h 55m2 stops Amsterdam Schiphol New York John F Kennedy Intl
£642Delta
Tue, 10 Nov - Tue, 17 Nov
United Airlines Logo
06:00 - 07:10PWM  Portland-LHR London Heathrow
44h 10m2 stops Newark Montreal Pierre Elliott Trudeau Intl
United Airlines Logo
06:50 - 23:21LHR  London Heathrow-PWM Portland
21h 31m2 stops Brussels Bruxelles-National Newark
£644United Airlines
Sat, 7 Nov - Fri, 20 Nov
Delta Logo
12:50 - 11:40PWM  Portland-LHR London Heathrow
17h 50m2 stops Detroit Metropolitan Wayne County Atlanta Hartsfield-Jackson
Delta Logo
08:40 - 23:33LHR  London Heathrow-PWM Portland
19h 53m2 stops Amsterdam Schiphol Atlanta Hartsfield-Jackson
£645Delta
Tue, 10 Nov - Tue, 17 Nov

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United Airlines flights from Portland, Maine to London

Our best United Airlines deals on Portland, Maine to London flight tickets
United Airlines
9 Nov
PWM08:45Portland
18h 40m
1 stop
LHR08:25London Heathrow
11 Nov
LHR06:50London Heathrow
21h 31m
2 stops
PWM23:21Portland
£548
United Airlines
9 Nov
PWM15:41Portland
13h 24m
2 stops
LHR10:05London Heathrow
11 Nov
LHR09:10London Heathrow
17h 41m
2 stops
PWM21:51Portland
£568
United Airlines
10 Nov
PWM15:10Portland
14h 55m
1 stop
LHR11:05London Heathrow
17 Nov
LHR06:50London Heathrow
17h 02m
2 stops
PWM18:52Portland
£641

Delta flights from Portland, Maine to London

Our best Delta deals on Portland, Maine to London flight tickets
Delta
10 Nov
PWM16:03Portland
13h 27m
1 stop
LHR10:30London Heathrow
17 Nov
LHR10:00London Heathrow
18h 55m
2 stops
PWM23:55Portland
£642
Delta
10 Nov
PWM12:50Portland
17h 50m
2 stops
LHR11:40London Heathrow
17 Nov
LHR08:40London Heathrow
19h 53m
2 stops
PWM23:33Portland
£645
Delta
10 Nov
PWM16:40Portland
18h 05m
2 stops
LGW15:45London Gatwick
25 Nov
LGW10:00London Gatwick
18h 55m
2 stops
PWM23:55Portland
£650

momondo Fare Finder

 
Customise your flight search to find flights from Portland, Maine 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, momondo users made 279,928 searches. Data last updated 10 August 2026.
Use the filters below to find and compare flights from Portland, Maine to London that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest return flight

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Mon 9/11

08:45-08:25

1 stop18h 40m

London Heathrow

Wed 11/11

06:50-23:21

2 stops21h 31m

£548

PortlandLondon

PWM Portland - LGW London Gatwick

PWMLGW

Portland

Wed 21/10

17:09-10:00

2 stops35h 51m

London Gatwick

Tue 27/10

10:10-09:08

1 stop26h 58m

£565

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Mon 9/11

15:41-10:05

2 stops13h 24m

London Heathrow

Wed 11/11

09:10-21:51

2 stops17h 41m

£568

PortlandLondon

PWM Portland - LGW London Gatwick

PWMLGW

Portland

Wed 21/10

09:48-10:00

1 stop19h 12m

London Gatwick

Tue 27/10

10:10-09:08

1 stop26h 58m

£611

PortlandLondon

PWM Portland - LGW London Gatwick

PWMLGW

Portland

Mon 19/10

07:00-10:00

2 stops22h 00m

London Gatwick

Fri 23/10

14:00-09:08

1 stop24h 08m

£637

PortlandLondon

PWM Portland - LGW London Gatwick

PWMLGW

Portland

Mon 19/10

09:48-10:00

1 stop19h 12m

London Gatwick

Fri 23/10

14:00-09:08

1 stop24h 08m

£639
Fastest return journey

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 10/11

14:05-06:40

1 stop11h 35m

London Heathrow

Tue 24/11

06:50-19:02

2 stops17h 12m

£641

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 10/11

16:03-10:30

1 stop13h 27m

London Heathrow

Tue 17/11

10:00-23:55

2 stops18h 55m

£642

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Sat 7/11

06:00-07:10

2 stops44h 10m

London Heathrow

Fri 20/11

06:50-23:21

2 stops21h 31m

£644

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 10/11

12:50-11:40

2 stops17h 50m

London Heathrow

Tue 17/11

08:40-23:33

2 stops19h 53m

£645

Flights are sorted by cheapest return flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to London from

How to get the cheapest flight ticket from Portland, Maine to London

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the typical price of a round-trip flight between Portland, Maine and London?

Prices are currently typical for flights on this route.

Typical prices usually range from £530 to £642.
The lowest price recently found on this route was £548.

What is the cheapest month to fly to London?

The cheapest month to fly to London from Portland, Maine is in January. Flight prices, which tend to average around £0, are often lower during this time because this is during the off-season. The month of December is another great option to travel to London, with average flight prices from Portland, Maine averaging around £518.

Can stopping save me money on Portland, Maine to London flights?

You could potentially save up to 26% on your flight if you consider stops on a Portland, Maine to London flight.

When to book flights from Portland, Maine to London

Are you open to changing your travel dates? Check out the ideal times to fly from Portland, Maine to London according to our flight data. Find out which month and days have the cheapest flights.
Estimated return price

Cheap Portland, Maine to London (PWM to LON) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Portland, Maine to London

Fastest flight time

9h 45m

Direct flights

None
The fastest flight from Portland, Maine to London takes 9h 45m
There are no direct flights from Portland, Maine to London. There are no popular flight routes from Portland, Maine to London.
Search flight deals

Frequently asked questions about flying from Portland, Maine to London

  • How far is Portland to London by plane?

    A flight from Portland to London will travel around 3183.1 mi. Typically, this will take 9h 45m by plane in normal conditions.

  • When did momondo last update prices for flights from Portland Airport to London?

    Prices for flights from Portland Airport to London refresh daily.

  • How old do you have to be to fly from Portland Airport to London?

    The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Portland Airport to London.

  • What documentation or ID do you need to fly to London?

    The necessary travel and health documents for your London trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

Travelling to a place near London?

Book flights to London if you plan to visit one of these locations
Eastbourne
Wembley
Gatwick
Milton Keynes
Luton
Southend-on-Sea
Slough
Ipswich
Maidstone
Folkestone
Ilford
Hastings
Canterbury
Chichester
Hayes
Guildford
Bedford
Harlow
Colchester
Chelmsford

Why use momondo?

Why should I use momondo to find a flight deal from Portland to London?

It is quick and easy to find Portland to London flights on momondo. We search and return numerous flight options from various airlines and agents. You can then use our filters to narrow your search until you have found the most convenient flight to London that suits you.

Can I find flights from Portland to London with flexible booking policies on momondo?

Yes. momondo allows you to filter the results for Portland to London flights to just show those with flexible booking policies.

How can momondo help me find flights from Portland to London?

momondo helps you find the best flight between Portland and London by providing filters to narrow your choice of flights to those matching your criteria. You can select flights based on numerous factors such as price, departure and landing times, airport and airline.

I’m not ready to book a flight from Portland to London right now. Can momondo alert me if prices change?

Yes. momondo can track prices for Portland to London flights and alert you when they change. Perform a search to set up the price alert. All that is required is a valid email address.

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Find better results for your trip to the United Kingdom

Fly into one of these airports located in London

Airports listed have a maximum distance of 35.6 mi from London
London City Airport
London Gatwick Airport
London Heathrow Airport
London Luton Airport
London Southend Airport
London Stansted Airport