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Cheap flights from Portland, Maine to London from £255

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 3/4. 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
0 bags
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Find the cheapest flights from Portland, Maine to London

Cheap return flights

Enter your travel dates to find the best prices.
Delta Logo
14:51 - 07:15
PWM
-
LHR
11h 24m
1 stop
Delta Logo
11:45 - 00:34
LHR
-
PWM
17h 49m
2 stops
£476Delta
Wed, 6 May - Wed, 13 May
Delta Logo
16:43 - 12:05
PWM
-
LHR
14h 22m
2 stops
Delta Logo
11:45 - 00:34
LHR
-
PWM
17h 49m
2 stops
£480Delta
Wed, 6 May - Wed, 13 May
United Airlines Logo
06:00 - 21:35
PWM
-
LHR
10h 35m
1 stop
United Airlines Logo
17:50 - 18:23
LHR
-
PWM
29h 33m
2 stops
£485United Airlines
Wed, 6 May - Mon, 11 May
United Airlines Logo
11:08 - 10:40
PWM
-
LHR
18h 32m
2 stops
United Airlines Logo
17:50 - 18:23
LHR
-
PWM
29h 33m
2 stops
£488United Airlines
Wed, 6 May - Mon, 11 May
KLM Logo
14:51 - 10:20
PWM
-
LHR
14h 29m
1 stop
KLM Logo
11:45 - 00:34
LHR
-
PWM
17h 49m
1 stop
£497KLM
Wed, 6 May - Wed, 13 May
JetBlue Logo
06:00 - 20:45
PWM
-
LHR
9h 45m
1 stop
JetBlue Logo
11:55 - 23:36
LHR
-
PWM
16h 41m
1 stop
£505JetBlue
Tue, 5 May - Tue, 12 May
JetBlue Logo
06:00 - 20:45
PWM
-
LHR
9h 45m
1 stop
JetBlue Logo
11:55 - 23:36
LHR
-
PWM
16h 41m
1 stop
£507JetBlue
Tue, 5 May - Tue, 12 May
Multiple Airlines Logo
09:47 - 10:00
PWM
-
LGW
19h 13m
1 stop
Multiple Airlines Logo
14:00 - 16:16
LGW
-
PWM
55h 16m
2 stops
£628Multiple Airlines
Mon, 4 May - Mon, 11 May
Multiple Airlines Logo
11:29 - 10:00
PWM
-
LGW
18h 31m
2 stops
Multiple Airlines Logo
14:00 - 09:07
LGW
-
PWM
23h 07m
1 stop
£628Multiple Airlines
Mon, 9 Mar - Thu, 12 Mar
KLM Logo
14:38 - 09:30
PWM
-
LCY
13h 52m
2 stops
KLM Logo
12:10 - 23:59
LCY
-
PWM
16h 49m
2 stops
£815KLM
Wed, 27 May - Sat, 13 Jun

United Airlines flights from Portland, Maine to London

Our best United Airlines deals on Portland, Maine to London flight tickets
United Airlines
6 May
PWM06:00Portland
10h 35m
1 stop
LHR21:35London Heathrow
11 May
LHR17:50London Heathrow
29h 33m
2 stops
PWM18:23Portland
£485
United Airlines
6 May
PWM11:08Portland
18h 32m
2 stops
LHR10:40London Heathrow
11 May
LHR17:50London Heathrow
29h 33m
2 stops
PWM18:23Portland
£488
United Airlines
20 Apr
PWM19:33Portland
29h 57m
2 stops
LHR06:30London Heathrow
27 Apr
LHR06:55London Heathrow
19h 45m
2 stops
PWM21:40Portland
£515

Air Canada flights from Portland, Maine to London

Our best Air Canada deals on Portland, Maine to London flight tickets
Air Canada
21 Apr
PWM19:12Portland
32h 23m
2 stops
LHR08:35London Heathrow
30 Apr
LHR14:05London Heathrow
38h 18m
2 stops
PWM23:23Portland
£482
Air Canada
20 Apr
PWM19:12Portland
33h 48m
2 stops
LHR10:00London Heathrow
30 Apr
LHR14:05London Heathrow
38h 18m
2 stops
PWM23:23Portland
£485
Air Canada
22 Apr
PWM06:00Portland
34h 00m
2 stops
LHR21:00London Heathrow
30 Apr
LHR14:05London Heathrow
38h 18m
2 stops
PWM23:23Portland
£519

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 17 February 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

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 6/5

14:51-07:15

1 stop11h 24m

London Heathrow

Wed 13/5

11:45-00:34

2 stops17h 49m

£476

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 6/5

16:43-12:05

2 stops14h 22m

London Heathrow

Wed 13/5

11:45-00:34

2 stops17h 49m

£480

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 6/5

06:00-21:35

1 stop10h 35m

London Heathrow

Mon 11/5

17:50-18:23

2 stops29h 33m

£485

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 6/5

11:08-10:40

2 stops18h 32m

London Heathrow

Mon 11/5

17:50-18:23

2 stops29h 33m

£488

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 6/5

14:51-10:20

1 stop14h 29m

London Heathrow

Wed 13/5

11:45-00:34

1 stop17h 49m

£497

PortlandLondon

PWM - LHR

PWMLHR

Portland

Tue 5/5

06:00-20:45

1 stop9h 45m

London Heathrow

Tue 12/5

11:55-23:36

1 stop16h 41m

£505

PortlandLondon

PWM - LHR

PWMLHR

Portland

Tue 5/5

06:00-20:45

1 stop9h 45m

London Heathrow

Tue 12/5

11:55-23:36

1 stop16h 41m

£507

PortlandLondon

PWM - LGW

PWMLGW

Portland

Mon 4/5

09:47-10:00

1 stop19h 13m

London Gatwick

Mon 11/5

14:00-16:16

2 stops55h 16m

£628

PortlandLondon

PWM - LGW

PWMLGW

Portland

Mon 9/3

11:29-10:00

2 stops18h 31m

London Gatwick

Thu 12/3

14:00-09:07

1 stop23h 07m

£628

PortlandLondon

PWM - LCY

PWMLCY

Portland

Wed 27/5

14:38-09:30

2 stops13h 52m

London City

Sat 13/6

12:10-23:59

2 stops16h 49m

£815

Flights are sorted by cheapest return flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
1
2

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 cheapest day to depart on your flight to London?

Our data shows that Monday is the least expensive day to fly to London. Tickets to fly out on this day can be as low as £438. When flying out on a Saturday, the most expensive travel day of the week, you can expect to see flight prices from Portland, Maine to London for around £531.

What is the cheapest time of day to depart on your flight to London?

The cheapest time of day to fly to London is in the afternoon when flights can be purchased for as low as £465. Flights in the morning are often more expensive, with an average ticket price of £533.

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

10h 10m

Direct flights

None
The fastest flight from Portland, Maine to London takes 10h 10m
There are no direct flights from Portland, Maine to London. There are no popular flight routes from Portland, Maine to London.
Search flight deals

  • How far is Portland to London by plane?

    A flight from Portland to London will travel around 3183.1 mi. Typically, this will take 10h 10m 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
Milton Keynes
Luton
Gatwick
Slough
Maidstone
Southend-on-Sea
Canterbury
Ipswich
Ilford
Guildford
Chelmsford
Hayes
Wembley
Dover
Folkestone
Colchester
Bedford
Worthing
Ramsgate

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