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Cheap flights from Portland, Maine to London from £248

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 10/12. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — LON
19 Dec — 26 Dec1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from Portland to London

Discover tips and strategies to find the most affordable flight options for your journey from Portland (PWM) to London (LON). 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 19 November 2025.

Round-trip from

£496

One-way from

£248

Popular in

June

Cheapest in

October

Average price

£646
KLM
  • KLM
  • 7/2-14/2
  • 2 total stops
  • 31h 39m total
  • Portland to London
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10/12
  • 10/12
  • 3 total stops
  • 35h 37m total
  • Portland to London
Search Deals
Highest demand for flights based on searches. 17% potential increase in price (£106 potential increase over avg. return price).
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Cheapest flight prices on average. 4% potential price decrease (£20 potential savings vs. average return price).
Search Deals
Average for round-trip flights in November 2025
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Find flight deals from Portland to London

Enter your travel dates to find the best prices.

Cheapest flights from Portland to London
Explore the most affordable flight options available from Portland to London. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 19 November 2025.

Wed 10/1216:53PWM - LHR
1 stop10h 52mDelta
Fri 19/1212:40LHR - PWM
1 stop15h 41mDelta
Deal found 18/11£644
Thu 11/1206:08PWM - LHR
2 stops19h 57mDelta
Thu 18/1208:55LHR - PWM
1 stop20h 04mDelta
Deal found 18/11£648
Wed 10/1214:34PWM - LHR
1 stop10h 46mDelta
Wed 17/1214:45LHR - PWM
2 stops28h 09mDelta
Deal found 18/11£669
Wed 10/1216:53PWM - LHR
1 stop10h 52mKLM
Wed 17/1210:10LHR - PWM
1 stop18h 54mKLM
Deal found 18/11£682
Thu 11/1212:53PWM - LHR
1 stop14h 52mAir France
Wed 17/1210:10LHR - PWM
1 stop18h 54mAir France
Deal found 18/11£728
Thu 11/1206:00PWM - LHR
3 stops20h 10mUnited Airlines
Thu 18/1216:20LHR - PWM
1 stop12h 39mUnited Airlines
Deal found 18/11£757
Tue 16/1219:46PWM - LHR
1 stop10h 19mUnited Airlines
Tue 23/1216:00LHR - PWM
1 stop12h 22mUnited Airlines
Deal found 18/11£772
Fri 12/1210:35PWM - LHR
1 stop29h 45mAustrian Airlines
Wed 17/1209:10LHR - PWM
1 stop14h 33mAustrian Airlines
Deal found 18/11£778
Fri 12/1206:15PWM - LHR
1 stop19h 40mDelta
Fri 19/1212:40LHR - PWM
2 stops28h 36mDelta
Deal found 18/11£785
Tue 16/1210:35PWM - LHR
1 stop18h 50mMultiple Airlines
Tue 23/1213:25LHR - PWM
2 stops34h 01mMultiple Airlines
Deal found 18/11£789
Wed 10/1206:00PWM - LHR
2 stops20h 10mAir Canada
Fri 19/1213:25LHR - PWM
2 stops38h 57mAir Canada
Deal found 18/11£845
Tue 16/1218:40PWM - LCY
2 stops13h 00mMultiple Airlines
Tue 23/1206:50LCY - PWM
2 stops16h 26mMultiple Airlines
Deal found 18/11£1,281

Cheapflights Fare Finder

 
Customise your flight search to find flights from Portland to London 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 19 November 2025.
Use the filters below to find and compare flights from Portland to London that are best for you.

Fly from

Portland

Fly to

London

Route

Depart

Return

Price

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sat 7/2

14:35-08:05

1 stop12h 30m

London Heathrow

Sat 14/2

08:55-23:04

1 stop19h 09m

£496

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sat 7/2

12:48-09:00

2 stops15h 12m

London Heathrow

Sat 14/2

08:55-23:04

1 stop19h 09m

£500

PortlandLondon

PWM - LCY

PWMLCY

Portland

Fri 23/1

14:35-09:30

2 stops13h 55m

London City

Tue 27/1

10:00-00:20

2 stops19h 20m

£503

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sun 10/5

06:00-20:45

1 stop9h 45m

London Heathrow

Sat 16/5

11:55-23:36

1 stop16h 41m

£563

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 1/1

13:03-06:20

1 stop12h 17m

London Heathrow

Sun 11/1

08:55-00:20

1 stop20h 25m

£573

PortlandLondon

PWM - LHR

PWMLHR

Portland

Fri 27/3

14:35-09:20

2 stops14h 45m

London Heathrow

Tue 31/3

10:35-23:49

2 stops42h 14m

£642

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 1/1

13:03-06:20

1 stop12h 17m

London Heathrow

Thu 8/1

08:55-22:27

1 stop18h 32m

£642

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 11/12

12:53-08:45

1 stop14h 52m

London Heathrow

Thu 18/12

10:10-23:59

1 stop18h 49m

£644

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 10/12

14:34-10:15

1 stop14h 41m

London Heathrow

Thu 18/12

10:45-22:23

1 stop16h 38m

£644

PortlandLondon

PWM - LHR

PWMLHR

Portland

Fri 12/12

14:34-06:55

1 stop11h 21m

London Heathrow

Thu 18/12

16:35-23:59

1 stop12h 24m

£644

Flights are sorted by cheapest return flights first.

Deals found on 16/11

Showing 1-10 of 26 results
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Best time to book a flight from Portland to London

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

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

Currently, August is the cheapest month in which you can book a flight from Portland, Maine to London (average of £236). Flying from Portland, Maine to London in June is currently the most expensive (average of £427). 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.

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

Share of one-stop return flights from Portland, Maine to London chosen by Cheapflights users in the past 12 months, using the same stopover each way.

Newark (EWR) – chosen by Cheapflights users on 40% of one-stop itineraries from Portland, Maine to London on Cheapflights.

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

Average return fare for one-stop flights from Portland, Maine to London, 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 £489.

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

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

Average stopover duration for one-stop one-way flights from Portland, Maine to London, 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 35m.

Related info for your journey

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

    Portland (PWM) is the airport you will fly out of if you book a flight from Portland to London. You should not have trouble finding flights to London from Portland; the airport handles an average of 0 outbound flights to London per day. You should also have plenty of airline options to choose from since 0 airlines have flights from the Portland airport to London. It is only a 2.9 mi journey to Portland (PWM) from Portland’s city center.

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

    There are many flights that can get you from Portland, Maine to London in 9h 45m. Fly via KLM, Delta, or JetBlue to get the fastest option. The distance between Portland, Maine and London is about 3173 mi. When browsing for deals, the options you’ll see will be for both direct flights and flights with stops.

  • What are the most popular routes from Portland, Maine to London?

    The most popular flight routes from Portland, Maine to London are Portland - London Heathrow, Portland - London Gatwick and Portland - London City.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Portland to London 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?

    Currently, August is the cheapest month in which you can book a flight from Portland, Maine to London (average of £236). Flying from Portland, Maine to London in June is currently the most expensive (average of £427). 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

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

Cheapflights helps you find that perfect flight to London from Portland by searching from hundreds of airlines and agencies you know and love. We are also free to use, in case you were wondering!

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

Certainly. Search results for flights to London from Portland shown to you on Cheapflights can be narrowed down with different useful search filters, which includes flexible booking options.

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

Yes, Cheapflights offers price alerts on Portland to London flights so you can book your travel at the perfect time. Price Alerts can be enabled by clicking the bell icon next to the flight deals above and providing your email address where you want to receive the alerts.

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