Find flights
When to book
FAQs

Cheap flights from Portland, Maine to London Heathrow Airport from £243

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 25/9. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — LHR
14 Sep — 21 Sep1
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 15 August 2026.

Mon 9/1108:45 -
1 stop18h 40m
Wed 11/1106:50 -
2 stops21h 31m
Deal found 10/8£546
Tue 10/1114:15 -
1 stop13h 45m
Tue 24/1106:30 -
2 stops22h 03m
Deal found 14/8£640
Sat 7/1106:00 -
2 stops44h 10m
Fri 20/1106:50 -
2 stops21h 31m
Deal found 10/8£643
Tue 10/1112:50 -
2 stops17h 50m
Tue 17/1106:30 -
2 stops22h 25m
Deal found 10/8£643
Sat 5/1217:06 -
2 stops33h 04m
Wed 9/1211:10 -
2 stops16h 47m
Deal found 11/8£646
Sat 12/906:00 -
1 stop9h 45m
Mon 28/911:55 -
1 stop16h 59m
Deal found 13/8£646
Mon 28/915:41 -
1 stop10h 34m
Mon 5/1017:55 -
2 stops29h 17m
Deal found 14/8£650
Sat 7/1108:45 -
2 stops40h 45m
Fri 20/1109:00 -
2 stops43h 21m
Deal found 13/8£651
Tue 10/1108:45 -
3 stops18h 45m
Tue 17/1106:00 -
3 stops22h 21m
Deal found 11/8£655

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 15 August 2026.

Round-trip from

£546

One-way from

£243

Popular in

June

Cheapest in

February

Average price

£895
United Airlines
  • United Airlines
  • 9/11-11/11
  • 3 total stops
  • 40h 11m total
  • Portland to London
Search Deals
JetBlue
  • JetBlue
  • 25/9
  • 1 total stop
  • 9h 45m total
  • Portland to London
Search Deals
Highest demand for flights based on searches. 20% potential increase in price (£160 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 10% potential price decrease (£61 potential savings vs. average return price).
Search Deals
Average for round-trip flights in August 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 15 August 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 Portland - LHR London Heathrow

PWMLHR

Portland

Mon 8/2

11:17-09:10

1 stop16h 53m

London Heathrow

Wed 10/2

06:50-22:57

2 stops21h 07m

£558
Fastest return journey

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Mon 9/11

15:41-10:05

2 stops13h 24m

London Heathrow

Wed 11/11

09:10-21:51

2 stops17h 41m

£566

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 10/11

16:03-10:30

1 stop13h 27m

London Heathrow

Tue 24/11

10:00-23:55

2 stops18h 55m

£640

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 10/11

15:41-10:25

1 stop13h 44m

London Heathrow

Tue 17/11

06:50-23:21

2 stops21h 31m

£640

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Sat 7/11

10:50-20:35

1 stop28h 45m

London Heathrow

Fri 20/11

06:50-09:00

2 stops31h 10m

£640

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Tue 10/11

12:50-09:00

2 stops15h 10m

London Heathrow

Tue 17/11

08:40-23:55

2 stops20h 15m

£644
Cheapest one-way
Fastest single journey

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Fri 25/9

06:00-20:45

1 stop9h 45m

£243

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Thu 29/10

06:30-21:35

2 stops35h 05m

£322

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Sun 11/10

16:15-13:45

2 stops16h 30m

£346

PortlandLondon

PWM Portland - LHR London Heathrow

PWMLHR

Portland

Fri 25/9

06:00-06:30

2 stops19h 30m

£379

Flights are sorted by cheapest return flights first.

Deals found on 11/8

Showing 1-10 of 16 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 50% 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 £426.

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 £558, United Airlines can have you in London Heathrow Airport from Portland, Maine in 16h 53m. The distance from Portland, Maine to London Heathrow Airport is about 3173 mi.

  • 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
Luton
Gatwick
Wembley
Ilford
Slough
Hayes
Croydon
Colchester
Brentford
Eastbourne
Northampton
Watford
Southend-on-Sea
Swindon
Enfield
Kingston upon Thames
Southall
Poole

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Portland to Heathrow

See prices for flight routes from nearby airports that may be better suited for you.
Boston to Heathrow flights
Boston to Gatwick flights
Boston to London City flights
Boston to Stansted flights
Boston to Luton flights
Bangor to Heathrow flights
Boston to Southend 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!

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.