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Cheap flights from Portland, Maine to London Heathrow Airport from £255

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 3/4. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — LHR
25 Mar — 1 Apr1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from Portland to Heathrow

Enter your travel dates to find the best prices.

Cheapest flights from Portland to Heathrow
Explore the most affordable flight options available from Portland to Heathrow. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 23 February 2026.

Wed 6/514:51
PWM
-
LHR
1 stop14h 29m
Delta
Wed 13/509:55
LHR
-
PWM
2 stops19h 39m
Delta
Deal found 19/2£481
Wed 6/515:39
PWM
-
LHR
2 stops14h 01m
United Airlines
Wed 13/506:50
LHR
-
PWM
2 stops16h 33m
United Airlines
Deal found 19/2£484
Wed 6/516:45
PWM
-
LHR
1 stop14h 00m
United Airlines
Mon 11/517:50
LHR
-
PWM
2 stops29h 33m
United Airlines
Deal found 19/2£490
Mon 30/306:00
PWM
-
LHR
1 stop9h 45m
JetBlue
Wed 15/408:15
LHR
-
PWM
1 stop19h 44m
JetBlue
Deal found 21/2£494
Wed 6/506:00
PWM
-
LHR
1 stop9h 45m
JetBlue
Mon 11/508:15
LHR
-
PWM
1 stop20h 21m
JetBlue
Deal found 21/2£497
Wed 6/514:51
PWM
-
LHR
1 stop12h 59m
KLM
Wed 13/509:20
LHR
-
PWM
1 stop18h 58m
KLM
Deal found 19/2£502
Tue 5/506:00
PWM
-
LHR
1 stop9h 45m
JetBlue
Wed 13/511:55
LHR
-
PWM
1 stop16h 41m
JetBlue
Deal found 20/2£509
Wed 6/506:00
PWM
-
LHR
1 stop9h 45m
JetBlue
Wed 13/511:55
LHR
-
PWM
1 stop16h 41m
JetBlue
Deal found 22/2£512
Wed 1/418:13
PWM
-
LHR
1 stop12h 32m
United Airlines
Sun 12/406:50
LHR
-
PWM
2 stops17h 11m
United Airlines
Deal found 19/2£518

Find flight deals from Portland to Heathrow

Discover tips and strategies to find the most affordable flight options for your journey from Portland (PWM) to Heathrow (LHR). 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 23 February 2026.

Round-trip from

£481

One-way from

£255

Popular in

June

Cheapest in

October

Average price

£582
Delta
  • Delta
  • 6/5-13/5
  • 3 total stops
  • 34h 08m total
  • Portland to London
Search Deals
JetBlue
  • JetBlue
  • 3/4
  • 1 total stop
  • 9h 45m total
  • Portland to London
Search Deals
Highest demand for flights based on searches. 16% potential increase in price (£108 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease (£27 potential savings vs. average return price).
Search Deals
Average for round-trip flights in February 2026
Search Deals

Cheapflights Fare Finder

 
Customise your flight search to find flights from Portland to Heathrow 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 23 February 2026.
Use the filters below to find and compare flights from Portland to London Heathrow Airport that are best for you.

Fly from

Portland

Fly to

Heathrow

Route

Depart

Return

Price

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 6/5

14:51-10:20

1 stop14h 29m

London Heathrow

Wed 13/5

09:55-00:34

2 stops19h 39m

£481

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 6/5

15:39-10:40

2 stops14h 01m

London Heathrow

Wed 13/5

06:50-18:23

2 stops16h 33m

£484

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 6/5

16:45-11:45

1 stop14h 00m

London Heathrow

Mon 11/5

17:50-18:23

2 stops29h 33m

£490

PortlandLondon

PWM - LHR

PWMLHR

Portland

Mon 30/3

06:00-20:45

1 stop9h 45m

London Heathrow

Wed 15/4

08:15-22:59

1 stop19h 44m

£494

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 6/5

14:51-08:50

1 stop12h 59m

London Heathrow

Wed 13/5

09:20-23:18

1 stop18h 58m

£502

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 6/5

06:00-20:45

1 stop9h 45m

London Heathrow

Mon 11/5

08:15-23:36

1 stop20h 21m

£508

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 6/5

12:46-12:05

2 stops18h 19m

London Heathrow

Mon 11/5

11:45-00:34

2 stops17h 49m

£521

PortlandLondon

PWM - LHR

PWMLHR

Portland

Tue 7/4

06:04-06:45

1 stop19h 41m

London Heathrow

Tue 14/4

06:50-18:58

2 stops17h 08m

£526

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 8/4

15:22-10:40

2 stops14h 18m

London Heathrow

Wed 15/4

06:50-18:58

2 stops17h 08m

£530

PortlandLondon

PWM - LHR

PWMLHR

Portland

Tue 24/3

12:51-10:15

2 stops17h 24m

London Heathrow

Tue 31/3

17:35-13:50

2 stops25h 15m

£532

Flights are sorted by cheapest return flights first.

Deals found on 22/2

Showing 1-10 of 21 results
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Best time to book a flight from Portland to Heathrow

Have a flexible travel schedule? Discover the best time to fly to Heathrow 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 Heathrow Airport

What is the cheapest month to book a flight from Portland, Maine to London Heathrow Airport?

Currently, October is the cheapest month in which you can book a flight from Portland, Maine to London Heathrow Airport (average of £323). Flying from Portland, Maine to London Heathrow Airport in June is currently the most expensive (average of £441). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

How much does it cost for a return flight from Portland, Maine to London Heathrow Airport?

Related info for your journey

Find useful and relevant information for your journey from Portland to Heathrow. 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 Heathrow?

    For a flight from Portland to London Heathrow, you will be flying from Portland. Portland (PWM) is just 2.9 mi from the center of the city. Portland is the only Portland airport and it handles 0 outbound flights to London Heathrow per day. 0 airlines have flights to London Heathrow from Portland on a regular basis.

  • How long is the flight from Portland, Maine to London Heathrow Airport?

    For as low as £494, Delta can have you in London Heathrow Airport from Portland, Maine in 9h 45m. The distance from Portland, Maine to London Heathrow Airport is about 3173 mi. This flight may include one or multiple stops.

  • Can I find deals for flights from Portland to Heathrow that include hotel bookings?

    Yes. In addition to deals on Portland to Heathrow flights, Cheapflights offers holiday packages that include both flights and hotel.

  • How can I find direct flights from Portland to Heathrow?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Portland to Heathrow.

  • Can I find deals for business class flights from Portland to Heathrow?

    Yes. Cheapflights offers flight deals from Portland to Heathrow by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Portland, Maine to London Heathrow Airport?

    Currently, October is the cheapest month in which you can book a flight from Portland, Maine to London Heathrow Airport (average of £323). Flying from Portland, Maine to London Heathrow Airport in June is currently the most expensive (average of £441). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Travelling to a place near London Heathrow Airport?

Book flights to London Heathrow Airport if you plan to visit one of these locations
Milton Keynes
Croydon
Wembley
Luton
Northampton
Gatwick
Slough
Hounslow
Ilford
Hayes
Brentford
Colchester
Watford
Guildford
Kingston upon Thames
Eastbourne
Ipswich
Chelmsford
Swindon
Bedford

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for Portland to Heathrow

See prices for flight routes from nearby airports that may be better suited for you.
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Boston to Southend flights
Bangor to Heathrow flights

Fly with Cheapflights

Find the best flight deals on Cheapflights, where travellers can enjoy low prices and a wide availability of flights to their desired destinations.

How does Cheapflights help users find flights from Portland to Heathrow?

Deals for Portland to Heathrow flights are sourced from 900+ travel sites when you use Cheapflights. When all flight results come back, Cheapflights lets you sort and filter flights using different criteria to choose better, like price, airport, cabin class, and plenty of other options.

Why should you use Cheapflights to find cheap flight tickets from Portland to Heathrow?

It’s simple! Cheapflights, which is free to use for everyone, saves millions of users time and money every year by helping them find the cheapest and most suitable flights from Portland to Heathrow.

Can Cheapflights find flights from Portland to Heathrow with no change fees?

Yes! Cheapflights helps users easily find flights from Portland to Heathrow with no change fees.

Can Cheapflights notify me if prices for flights from Portland to Heathrow become cheaper?

Yes, and it’s super simple to set up. Click the bell icon next to the flight deals above and provide a valid email address to enable Price Alerts. That’s it!

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