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Cheap flights from Portland, Maine to London Heathrow Airport from £228

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 24/8. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — LHR
26 Apr — 3 May1
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 March 2026.

Mon 24/806:00
PWM
-
LHR
1 stop10h 35m
United Airlines
Tue 25/817:50
LHR
-
PWM
2 stops28h 54m
United Airlines
Deal found 23/3£530
Wed 6/514:51
PWM
-
LHR
1 stop16h 14m
Delta
Mon 11/508:55
LHR
-
PWM
2 stops20h 48m
Delta
Deal found 26/3£542
Wed 6/514:51
PWM
-
LHR
1 stop14h 29m
KLM
Mon 11/508:20
LHR
-
PWM
1 stop21h 23m
KLM
Deal found 26/3£547
Mon 9/1116:48
PWM
-
LHR
1 stop34h 07m
United Airlines
Thu 12/1106:50
LHR
-
PWM
2 stops16h 23m
United Airlines
Deal found 26/3£563
Thu 3/914:35
PWM
-
LHR
2 stops18h 15m
Delta
Mon 7/906:30
LHR
-
PWM
2 stops22h 29m
Delta
Deal found 26/3£565
Sun 30/814:35
PWM
-
LHR
1 stop10h 45m
Delta
Tue 8/908:40
LHR
-
PWM
2 stops20h 19m
Delta
Deal found 26/3£566
Mon 7/1214:45
PWM
-
LHR
1 stop15h 05m
United Airlines
Wed 9/1207:30
LHR
-
PWM
2 stops15h 43m
United Airlines
Deal found 23/3£597
Sun 11/1012:50
PWM
-
LHR
1 stop13h 20m
Delta
Thu 22/1009:55
LHR
-
PWM
2 stops18h 54m
Delta
Deal found 23/3£618

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 March 2026.

Round-trip from

£530

One-way from

£228

Popular in

December

Cheapest in

October

Average price

£799
United Airlines
  • United Airlines
  • 24/8-25/8
  • 3 total stops
  • 39h 29m total
  • Portland to London
Search Deals
American Airlines
  • American Airlines
  • 24/8
  • 1 total stop
  • 13h 46m total
  • Portland to London
Search Deals
Highest demand for flights based on searches. 8% potential increase in price (£46 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 6% potential price decrease (£31 potential savings vs. average return price).
Search Deals
Average for round-trip flights in March 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 March 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

Sun 10/5

06:25-06:20

1 stop18h 55m

London Heathrow

Sat 16/5

08:40-00:43

2 stops21h 03m

£542

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sun 30/8

14:35-06:20

1 stop10h 45m

London Heathrow

Tue 8/9

08:40-23:59

2 stops20h 19m

£566

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sun 20/9

14:35-08:50

1 stop13h 15m

London Heathrow

Sat 3/10

08:40-23:59

2 stops20h 19m

£656
Fastest return journey

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 6/5

14:08-06:55

1 stop11h 47m

London Heathrow

Wed 13/5

10:50-23:29

2 stops17h 39m

£657

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 6/5

07:20-22:25

2 stops34h 05m

London Heathrow

Mon 11/5

18:30-23:03

2 stops33h 33m

£658

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 6/5

07:20-16:00

2 stops27h 40m

London Heathrow

Wed 13/5

06:30-23:03

2 stops21h 33m

£658

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 6/5

14:08-10:40

1 stop15h 32m

London Heathrow

Mon 11/5

17:50-18:23

2 stops29h 33m

£667

PortlandLondon

PWM - LHR

PWMLHR

Portland

Tue 25/8

05:15-06:30

2 stops20h 15m

London Heathrow

Mon 7/9

06:55-19:19

2 stops17h 24m

£668

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 6/5

07:20-09:30

1 stop21h 10m

London Heathrow

Mon 11/5

08:15-23:03

1 stop19h 48m

£669

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 3/9

14:25-20:45

1 stop25h 20m

London Heathrow

Mon 7/9

08:15-23:57

1 stop20h 42m

£673

Flights are sorted by cheapest return flights first.

Deals found on 23/3

Showing 1-10 of 22 resultsSorted by cheapest first
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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 £326). Flying from Portland, Maine to London Heathrow Airport in June is currently the most expensive (average of £444). 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 £657, Delta can have you in London Heathrow Airport from Portland, Maine in 11h 47m. 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 £326). Flying from Portland, Maine to London Heathrow Airport in June is currently the most expensive (average of £444). 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
Wembley
Croydon
Northampton
Hounslow
Luton
Gatwick
Slough
Ilford
Hayes
Brentford
Colchester
Eastbourne
Guildford
Watford
Kingston upon Thames
Romford
Ipswich
Swindon
Bedford

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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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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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