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Cheap flights from Portland, Maine to London Heathrow Airport from £254

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 — LHR
26 Jun — 3 Jul1
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 27 May 2026.

Wed 11/1117:06
PWM
-
LHR
1 stop12h 19m
United Airlines
Fri 13/1106:50
LHR
-
PWM
2 stops16h 23m
United Airlines
Deal found 26/5£564
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£583
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£596
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£635
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£642
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£643
Tue 10/1106:00
PWM
-
LHR
1 stop19h 25m
Delta
Tue 24/1108:40
LHR
-
PWM
2 stops18h 43m
Delta
Deal found 22/5£644
Tue 10/1112:50
PWM
-
LHR
2 stops15h 45m
Delta
Tue 17/1106:30
LHR
-
PWM
2 stops22h 19m
Delta
Deal found 26/5£647
Tue 1/916:47
PWM
-
LHR
2 stops15h 28m
Delta
Sat 12/908:40
LHR
-
PWM
2 stops20h 19m
Delta
Deal found 23/5£648

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 27 May 2026.

Round-trip from

£564

One-way from

£254

Popular in

July

Cheapest in

October

Average price

£543
United Airlines
  • United Airlines
  • 11/11-13/11
  • 3 total stops
  • 28h 42m 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 (£132 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 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 27 May 2026.
Use the filters below to find and compare flights from Portland to London Heathrow Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest return flight

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 11/11

14:45-09:10

2 stops13h 25m

London Heathrow

Fri 13/11

06:50-16:09

2 stops14h 19m

£616

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

£644

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

£644

PortlandLondon

PWM - LHR

PWMLHR

Portland

Tue 1/9

14:53-10:20

1 stop14h 27m

London Heathrow

Sat 12/9

08:40-23:59

2 stops20h 19m

£644

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sun 27/9

06:00-20:40

1 stop9h 40m

London Heathrow

Wed 30/9

06:50-20:02

2 stops18h 12m

£659

PortlandLondon

PWM - LHR

PWMLHR

Portland

Fri 11/9

14:35-10:20

1 stop14h 45m

London Heathrow

Thu 17/9

15:50-23:59

1 stop13h 09m

£666
Fastest return journey

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sun 27/9

13:53-06:50

1 stop11h 57m

London Heathrow

Wed 30/9

13:10-23:47

1 stop15h 37m

£667
Cheapest one-way
Fastest single journey

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sun 9/8

14:53-08:50

1 stop12h 57m

£254

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 23/7

06:00-06:25

1 stop19h 25m

£254

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sun 12/7

06:00-09:30

1 stop22h 30m

£274

Flights are sorted by cheapest return flights first.

Deals found on 25/5

Showing 1-10 of 18 resultsSorted by cheapest first
1
2

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’s the top stopover airport for flights from Portland, Maine to London Heathrow Airport?

Share of one-stop return flights from Portland, Maine to London Heathrow Airport 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 Heathrow Airport on Cheapflights.

What’s the cheapest stopover airport for flights from Portland, Maine to London Heathrow Airport?

Average return fare for one-stop flights from Portland, Maine to London Heathrow Airport, 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 £427.

What’s the fastest stopover option from Portland, Maine to London Heathrow Airport?

Shortest average travel time for one-stop one-way flights from Portland, Maine to London Heathrow Airport, 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 Heathrow Airport?

Average stopover duration for one-stop one-way flights from Portland, Maine to London Heathrow Airport, 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 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 £616, United Airlines can have you in London Heathrow Airport from Portland, Maine in 13h 25m. 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.

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
Hounslow
Milton Keynes
Northampton
Wembley
Luton
Gatwick
Croydon
Ilford
Slough
Hayes
Brentford
Colchester
Kingston upon Thames
Eastbourne
Ipswich
Watford
Swindon
Romford
Guildford
Borehamwood

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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