What is the cheapest airline that flies from Portland to London?

Delta and United Airlines are the most popular carriers operating from Portland to London

What airlines fly to London?

British Airways, Delta and Virgin Atlantic are the top three most popular airlines that fly to London from Portland, Maine according to our data. British Airways is the first choice among our users, with 47% of people opting to fly with this airline when traveling to London. Keep in mind that there are 16 different airlines that fly to London on a routine basis, so you have a few additional options to choose from.

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

Prices for flights from Portland Airport to London refresh daily.

How many operators does momondo search for flights from Portland Airport to London?

There is 1 operator available for flights from Portland Airport to London as of November 2026.

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

Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Portland Airport to London.

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

The travel and health documents required for your trip to London can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at London. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

$347 Cheap Flights from Portland, Maine to London in 2026/27

Discover deals from 900+ travel sites with momondo.

Find the cheapest flights from Portland, Maine to London

Round-trip

One-way

Last minute

Cheap round-trip flights

Enter your travel dates to find the best prices.

3:14 pm - 10:25 amPWM Portland-LHR London Heathrow

14h 11m1 stop Newark

6:50 am - 11:25 pmLHR London Heathrow-PWM Portland

21h 35m2 stops Brussels Bruxelles-National Newark

$763United Airlines

Tue, Feb 23 - Thu, Feb 25

8:42 am - 10:50 amPWM Portland-LHR London Heathrow

45h 08m2 stops Newark Washington, D.C. Dulles Intl

6:50 am - 1:38 pmLHR London Heathrow-PWM Portland

35h 48m2 stops Brussels Bruxelles-National Newark

$767United Airlines

Tue, Mar 2 - Fri, Mar 5

4:40 pm - 7:55 amPWM Portland-LHR London Heathrow

34h 15m1 stop Chicago O'Hare Intl

6:50 am - 1:38 pmLHR London Heathrow-PWM Portland

35h 48m2 stops Brussels Bruxelles-National Newark

$768United Airlines

Tue, Mar 2 - Fri, Mar 5

3:14 pm - 11:15 amPWM Portland-LHR London Heathrow

15h 01m2 stops Newark Zurich

6:50 am - 6:50 pmLHR London Heathrow-PWM Portland

17h 00m2 stops Brussels Bruxelles-National Newark

$819United Airlines

Tue, Feb 23 - Thu, Feb 25

6:00 am - 9:00 pmPWM Portland-LHR London Heathrow

34h 00m2 stops Newark Halifax Intl

9:00 am - 9:12 pmLHR London Heathrow-PWM Portland

41h 12m2 stops Halifax Intl Newark

$852Air Canada

Tue, Dec 1 - Wed, Dec 9

12:49 pm - 7:45 amPWM Portland-LHR London Heathrow

13h 56m1 stop Detroit Metropolitan Wayne County

11:45 am - 12:21 amLHR London Heathrow-PWM Portland

17h 36m2 stops Amsterdam Schiphol New York John F Kennedy Intl

$862KLM

Tue, Dec 1 - Wed, Dec 9

3:20 pm - 6:20 amPWM Portland-LHR London Heathrow

10h 00m1 stop Newark

6:50 am - 7:25 pmLHR London Heathrow-PWM Portland

17h 35m2 stops Brussels Bruxelles-National Newark

$876United Airlines

Tue, Dec 1 - Sun, Dec 6

4:47 pm - 12:00 pmPWM Portland-LHR London Heathrow

14h 13m1 stop Chicago O'Hare Intl

9:00 am - 9:05 amLHR London Heathrow-PWM Portland

29h 05m2 stops Zurich Newark

$876United Airlines

Fri, Dec 4 - Tue, Dec 8

7:55 pm - 7:10 amPWM Portland-LHR London Heathrow

30h 15m2 stops Newark Montreal Pierre Elliott Trudeau Intl

6:50 am - 7:25 pmLHR London Heathrow-PWM Portland

17h 35m2 stops Brussels Bruxelles-National Newark

$880United Airlines

Tue, Dec 1 - Sun, Dec 6

12:49 pm - 10:30 amPWM Portland-LHR London Heathrow

16h 41m2 stops Detroit Metropolitan Wayne County Paris Charles de Gaulle

10:00 am - 11:33 pmLHR London Heathrow-PWM Portland

18h 33m2 stops Amsterdam Schiphol Atlanta Hartsfield-Jackson

$882Delta

Fri, Dec 4 - Tue, Dec 8

Cheap last minute flights

Enter your travel dates to find the best prices.

3:40 pm - 9:10 amPWM Portland-LHR London Heathrow

12h 30m1 stop Newark

12:05 pm - 11:21 pmLHR London Heathrow-PWM Portland

16h 16m2 stops Zurich Newark

$875United Airlines

Sun, Nov 15 - Thu, Nov 19

3:40 pm - 9:10 amPWM Portland-LHR London Heathrow

12h 30m1 stop Newark

12:05 pm - 11:21 pmLHR London Heathrow-PWM Portland

16h 16m2 stops Zurich Newark

$876United Airlines

Sun, Nov 15 - Thu, Nov 19

10:50 am - 8:25 amPWM Portland-LHR London Heathrow

16h 35m1 stop Newark

12:05 pm - 11:21 pmLHR London Heathrow-PWM Portland

16h 16m2 stops Zurich Newark

$876United Airlines

Tue, Nov 17 - Mon, Nov 23

8:49 am - 9:10 amPWM Portland-LHR London Heathrow

19h 21m1 stop Newark

6:50 am - 11:59 pmLHR London Heathrow-PWM Portland

22h 09m2 stops Brussels Bruxelles-National Washington, D.C. Dulles Intl

$876United Airlines

Tue, Nov 17 - Tue, Nov 24

8:47 am - 5:55 amPWM Portland-LHR London Heathrow

16h 08m1 stop Chicago O'Hare Intl

6:50 am - 11:21 pmLHR London Heathrow-PWM Portland

21h 31m2 stops Brussels Bruxelles-National Newark

$876United Airlines

Sun, Nov 15 - Tue, Nov 24

5:35 am - 9:20 pmPWM Portland-LHR London Heathrow

10h 45m1 stop Newark

6:50 am - 11:21 pmLHR London Heathrow-PWM Portland

21h 31m2 stops Brussels Bruxelles-National Newark

$876United Airlines

Mon, Nov 16 - Tue, Nov 24

5:30 am - 6:40 amPWM Portland-LHR London Heathrow

20h 10m1 stop Washington, D.C. Dulles Intl

6:50 am - 11:21 pmLHR London Heathrow-PWM Portland

21h 31m2 stops Brussels Bruxelles-National Newark

$876United Airlines

Wed, Nov 18 - Tue, Nov 24

2:05 pm - 10:25 amPWM Portland-LHR London Heathrow

15h 20m2 stops Washington, D.C. Dulles Intl Newark

12:05 pm - 11:21 pmLHR London Heathrow-PWM Portland

16h 16m2 stops Zurich Newark

$880United Airlines

Sun, Nov 15 - Thu, Nov 19

4:03 pm - 1:45 pmPWM Portland-LHR London Heathrow

16h 42m2 stops New York John F Kennedy Intl Paris Charles de Gaulle

10:00 am - 12:19 amLHR London Heathrow-PWM Portland

19h 19m2 stops Amsterdam Schiphol New York John F Kennedy Intl

$881Delta

Mon, Nov 16 - Tue, Nov 24

11:59 am - 7:55 amPWM Portland-LHR London Heathrow

14h 56m2 stops New York LaGuardia Paris Charles de Gaulle

6:30 am - 11:21 pmLHR London Heathrow-PWM Portland

21h 51m2 stops Amsterdam Schiphol New York John F Kennedy Intl

$881Delta

Sun, Nov 15 - Tue, Nov 24

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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

Feb 23

PWM3:14 pmPortland

14h 11m

1 stop

LHR10:25 amLondon Heathrow

Feb 25

LHR6:50 amLondon Heathrow

21h 35m

2 stops

PWM11:25 pmPortland

$763

United Airlines

Mar 2

PWM8:42 amPortland

45h 08m

2 stops

LHR10:50 amLondon Heathrow

Mar 5

LHR6:50 amLondon Heathrow

35h 48m

2 stops

PWM1:38 pmPortland

$767

United Airlines

Mar 2

PWM4:40 pmPortland

34h 15m

1 stop

LHR7:55 amLondon Heathrow

Mar 5

LHR6:50 amLondon Heathrow

35h 48m

2 stops

PWM1:38 pmPortland

$768

Delta flights from Portland, Maine to London

Our best Delta deals on Portland, Maine to London flight tickets

Delta

Nov 15

PWM11:59 amPortland

14h 56m

2 stops

LHR7:55 amLondon Heathrow

Nov 24

LHR6:30 amLondon Heathrow

21h 51m

2 stops

PWM11:21 pmPortland

$881

Delta

Dec 4

PWM12:49 pmPortland

16h 41m

2 stops

LHR10:30 amLondon Heathrow

Dec 8

LHR10:00 amLondon Heathrow

18h 33m

2 stops

PWM11:33 pmPortland

$882

Delta

Apr 6

PWM2:35 pmPortland

11h 50m

1 stop

LHR7:25 amLondon Heathrow

Apr 14

LHR11:45 amLondon Heathrow

17h 04m

2 stops

PWM11:49 pmPortland

$894

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 2/23

3:14 pm-10:25 am

1 stop14h 11m

London Heathrow

Thu 2/25

6:50 am-11:25 pm

2 stops21h 35m

$763

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 3/2

8:42 am-10:50 am

2 stops45h 08m

London Heathrow

Fri 3/5

6:50 am-1:38 pm

2 stops35h 48m

$767

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 3/2

4:40 pm-7:55 am

1 stop34h 15m

London Heathrow

Fri 3/5

6:50 am-1:38 pm

2 stops35h 48m

$768

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 2/23

3:14 pm-11:15 am

2 stops15h 01m

London Heathrow

Thu 2/25

6:50 am-6:50 pm

2 stops17h 00m

$819

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 12/1

6:00 am-9:00 pm

2 stops34h 00m

London Heathrow

Wed 12/9

9:00 am-9:12 pm

2 stops41h 12m

$852

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 12/1

12:49 pm-7:45 am

1 stop13h 56m

London Heathrow

Wed 12/9

11:45 am-12:21 am

2 stops17h 36m

$862

Quickest round-trip

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 12/1

3:20 pm-6:20 am

1 stop10h 00m

London Heathrow

Sun 12/6

6:50 am-7:25 pm

2 stops17h 35m

$876

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Fri 12/4

4:47 pm-12:00 pm

1 stop14h 13m

London Heathrow

Tue 12/8

9:00 am-9:05 am

2 stops29h 05m

$876

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 12/1

7:55 pm-7:10 am

2 stops30h 15m

London Heathrow

Sun 12/6

6:50 am-7:25 pm

2 stops17h 35m

$880

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Fri 12/4

12:49 pm-10:30 am

2 stops16h 41m

London Heathrow

Tue 12/8

10:00 am-11:33 pm

2 stops18h 33m

$882

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first

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

Prices

Airlines

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 February is another great option to travel to London, with average flight prices from Portland, Maine averaging around $752.

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

You could potentially save up to 17% 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 round-trip 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

Best Price Found	$347
Fastest flight time	10h 00m
Direct flights	None

The best one-way flight to London from Portland, Maine in the past 72 hours is $347. The best round-trip flight deal from Portland, Maine to London found on momondo in the last 72 hours is $763.

The fastest flight from Portland, Maine to London takes 10h 00m

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?
London is 3183.1 mi away from Portland. Typically, this will take 10h 00m 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 many operators does momondo search for flights from Portland Airport to London?
There is 1 operator available for flights from Portland Airport to London as of November 2026.
How old do you have to be to fly from Portland Airport to London?
Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Portland Airport to London.
What documentation or ID do you need to fly to London?
The travel and health documents required for your trip to London can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at London. We always recommend checking with your airline or a trusted third party such as IATA to get advice.
What is the most popular airline from Portland, Maine to London?
Based on momondo bookings for this flight route, the most popular airline on flight routes from Portland, Maine to London is United Airlines (100% of total bookings).

Best airlines flying from Portland, Maine to London

Compare and see reviews for airlines that fly from Portland, Maine to London with momondo

Airline	Rating	Free Cancellation	Price
United Airlines	PriceFrom $752	Free Cancellation	Rating 7.3 10,486 reviews		Search United Airlines flights

Hounslow

Gatwick

Croydon

Hayes

Haverhill

Milton Keynes

Luton

Stansted

Kingston upon Thames

Dover

Watford

Richmond

Wembley

Crawley

Worthing

Brentford

Harrow

Canterbury

Hook

Southall

Why use momondo?

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

We help find the flight that best suits your needs, momondo compares prices from hundreds of airlines and travel agents and helps you filter them to find the best flight from Portland to London for you.

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

Yes. All flights to London from Portland on momondo can be compared and filtered by various policies on offer, including flexible booking.

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

Once all potential Portland to London flight options are in front of you, momondo lets you sort and filter flights based on preferences such as airline, price and flight times amongst many other options.

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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Cheap flights from Portland, Maine to London from $347

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 11/23. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.

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United Airlines flights from Portland, Maine to London

Our best United Airlines deals on Portland, Maine to London flight tickets

Delta flights from Portland, Maine to London

Our best Delta deals on Portland, Maine to London flight tickets

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

What is the cheapest month to fly to London?

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

What is the cheapest airline that flies from Portland to London?

What airlines fly to London?

When to book flights from Portland, Maine to London

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

Best Price Found

Fastest flight time

Direct flights

Frequently asked questions about flying from Portland, Maine to London

Best airlines flying from Portland, Maine to London

Compare and see reviews for airlines that fly from Portland, Maine to London with momondo

Traveling to a place near London?

Why use momondo?

An easier way to manage your London trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.

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

Fly your favorite airline to London

Airlines are sorted and displayed according to clicks in the past 7 days on momondo

Cabin classes currently available on flights to London

List of cabin classes available on flights landing in London. Availability may vary depending on flight origin and airline.

Popular cities in the United Kingdom

Popular flights according to clicks in the last 7 days on momondo

Fly to other destinations from Portland, Maine

According to popular flight searches on momondo this year

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