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Cheap flights from Portland, Maine to London from £385

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 21/12. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — LON
22 Nov — 29 Nov1
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 23 October 2025.

Round-trip from

£445

One-way from

£385

Popular in

June

Cheapest in

October

Average price

£478
Delta
  • Delta
  • 18/11-25/11
  • 3 total stops
  • 32h 14m total
  • Portland to London
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Air Canada
  • Air Canada
  • 21/12
  • 2 total stops
  • 48h 40m total
  • Portland to London
Search Deals
Highest demand for flights based on searches. 16% potential increase in price (£98 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease (£18 potential savings vs. average return price).
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Average for round-trip flights in October 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 23 October 2025.

Tue 18/1114:30PWM - LHR
1 stop11h 25mDelta
Tue 25/1106:30LHR - PWM
2 stops20h 49mDelta
Deal found 22/10£445
Tue 18/1116:53PWM - LHR
1 stop10h 52mKLM
Tue 25/1110:45LHR - PWM
1 stop16h 34mKLM
Deal found 22/10£449
Thu 27/1109:00PWM - LHR
2 stops28h 30mScandinavian Airlines
Wed 3/1206:40LHR - PWM
2 stops22h 19mScandinavian Airlines
Deal found 23/10£477
Sun 7/1212:53PWM - LHR
1 stop14h 52mAir France
Sun 14/1208:55LHR - PWM
1 stop18h 28mAir France
Deal found 23/10£480
Thu 27/1106:00PWM - LHR
1 stop19h 25mDelta
Thu 4/1206:20LHR - PWM
2 stops22h 39mDelta
Deal found 21/10£482
Thu 27/1106:00PWM - LHR
1 stop19h 25mDelta
Fri 5/1211:45LHR - PWM
2 stops17h 14mDelta
Deal found 21/10£482
Thu 27/1109:00PWM - LHR
2 stops31h 40mScandinavian Airlines
Tue 2/1219:30LHR - PWM
2 stops33h 29mScandinavian Airlines
Deal found 21/10£483
Thu 27/1106:00PWM - LHR
1 stop19h 25mDelta
Wed 3/1211:45LHR - PWM
2 stops17h 14mDelta
Deal found 23/10£485
Sun 7/1216:53PWM - LHR
1 stop10h 52mDelta
Sun 14/1208:40LHR - PWM
2 stops36h 27mDelta
Deal found 23/10£486
Thu 27/1115:15PWM - LGW
2 stops37h 45mMultiple Airlines
Fri 5/1214:00LGW - PWM
1 stop25h 36mMultiple Airlines
Deal found 23/10£509
Thu 27/1115:15PWM - LGW
2 stops37h 45mMultiple Airlines
Thu 4/1214:00LGW - PWM
1 stop24h 06mMultiple Airlines
Deal found 23/10£547
Thu 27/1109:54PWM - LCY
2 stops22h 01mMultiple Airlines
Tue 2/1218:15LCY - PWM
2 stops29h 28mMultiple Airlines
Deal found 21/10£550

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 23 October 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

Tue 18/11

14:30-06:55

1 stop11h 25m

London Heathrow

Tue 25/11

06:30-22:19

2 stops20h 49m

£445

PortlandLondon

PWM - LHR

PWMLHR

Portland

Tue 18/11

16:53-08:45

1 stop10h 52m

London Heathrow

Tue 25/11

10:45-22:19

1 stop16h 34m

£449

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 27/11

09:00-18:30

2 stops28h 30m

London Heathrow

Wed 3/12

06:40-23:59

2 stops22h 19m

£477

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sun 7/12

16:53-08:45

1 stop10h 52m

London Heathrow

Sun 14/12

08:55-22:23

1 stop18h 28m

£481

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 11/12

14:34-10:15

1 stop14h 41m

London Heathrow

Tue 16/12

09:00-23:59

2 stops19h 59m

£482

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 27/11

09:00-21:40

2 stops31h 40m

London Heathrow

Thu 4/12

17:00-23:59

2 stops35h 59m

£482

PortlandLondon

PWM - LHR

PWMLHR

Portland

Sun 7/12

12:53-08:45

1 stop14h 52m

London Heathrow

Sun 14/12

11:45-23:59

2 stops17h 14m

£482

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 27/11

09:00-21:40

2 stops31h 40m

London Heathrow

Tue 2/12

10:20-23:59

2 stops42h 39m

£482

PortlandLondon

PWM - LGW

PWMLGW

Portland

Thu 27/11

15:15-10:00

2 stops37h 45m

London Gatwick

Fri 5/12

14:00-10:36

1 stop25h 36m

£509

PortlandLondon

PWM - LCY

PWMLCY

Portland

Thu 19/2

14:35-08:50

2 stops13h 15m

London City

Thu 26/2

10:00-21:59

2 stops16h 59m

£530

Flights are sorted by cheapest return flights first.

Deals found on 21/10

Showing 1-10 of 25 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 £233). Flying from Portland, Maine to London in June is currently the most expensive (average of £413). 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?

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 £481.

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 10h 52m. Fly via Delta, KLM, or Scandinavian Airlines 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 City and Portland - London Gatwick.

  • 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 £233). Flying from Portland, Maine to London in June is currently the most expensive (average of £413). 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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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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