Cheap flights from Portland, Maine to London from £255

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 3/4. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — LON
27 Mar — 3 Apr1
1 adult
1 adult, Economy, 0 bags

Cheap 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 25 February 2026.

Wed 2/906:00
PWM
-
LHR
2 stops23h 00m
Air Canada
Fri 4/912:40
LHR
-
PWM
2 stops34h 47m
Air Canada
Deal found 23/2£488
Wed 2/906:00
PWM
-
LHR
2 stops19h 30m
Air Canada
Tue 8/914:05
LHR
-
PWM
2 stops33h 22m
Air Canada
Deal found 23/2£490
Mon 30/306:00
PWM
-
LHR
1 stop9h 45m
JetBlue
Wed 15/408:15
LHR
-
PWM
1 stop19h 44m
JetBlue
Deal found 21/2£493
Wed 6/506:00
PWM
-
LHR
1 stop9h 45m
JetBlue
Mon 11/508:15
LHR
-
PWM
1 stop20h 21m
JetBlue
Deal found 21/2£496
Mon 27/407:30
PWM
-
LHR
1 stop21h 00m
JetBlue
Mon 4/508:15
LHR
-
PWM
1 stop20h 21m
JetBlue
Deal found 23/2£500
Wed 2/906:00
PWM
-
LHR
1 stop10h 35m
United Airlines
Fri 4/908:00
LHR
-
PWM
1 stop18h 27m
United Airlines
Deal found 23/2£502
Wed 2/906:00
PWM
-
LHR
1 stop10h 35m
United Airlines
Tue 8/909:30
LHR
-
PWM
2 stops13h 57m
United Airlines
Deal found 23/2£505
Wed 6/506:30
PWM
-
LHR
2 stops22h 05m
Scandinavian Airlines
Wed 13/507:05
LHR
-
PWM
2 stops22h 38m
Scandinavian Airlines
Deal found 25/2£510
Wed 6/506:00
PWM
-
LHR
1 stop9h 45m
JetBlue
Wed 13/511:55
LHR
-
PWM
1 stop16h 41m
JetBlue
Deal found 22/2£511
Wed 2/906:00
PWM
-
LHR
1 stop10h 35m
United Airlines
Sun 6/906:50
LHR
-
PWM
2 stops15h 22m
United Airlines
Deal found 23/2£518
Wed 1/412:51
PWM
-
LCY
2 stops15h 39m
Delta
Wed 8/409:20
LCY
-
PWM
2 stops19h 02m
Delta
Deal found 24/2£551
Wed 6/514:51
PWM
-
LGW
2 stops13h 34m
Delta
Mon 11/510:25
LGW
-
PWM
2 stops19h 18m
Delta
Deal found 24/2£571

Find 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 25 February 2026.

Round-trip from

£493

One-way from

£255

Popular in

July

Cheapest in

October

Average price

£499
JetBlue
  • JetBlue
  • 30/3-15/4
  • 2 total stops
  • 29h 29m total
  • Portland to London
JetBlue
  • JetBlue
  • 3/4
  • 1 total stop
  • 9h 45m total
  • Portland to London
Highest demand for flights based on searches. 19% potential increase in price (£111 potential increase over avg. return price).
Cheapest flight prices on average. 4% potential price decrease (£21 potential savings vs. average return price).
Average for round-trip flights in February 2026

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 25 February 2026.
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

Mon 30/3

06:00-20:45

1 stop9h 45m

London Heathrow

Wed 15/4

08:15-22:59

1 stop19h 44m

£493

PortlandLondon

PWM - LHR

PWMLHR

Portland

Tue 7/4

06:04-06:45

1 stop19h 41m

London Heathrow

Tue 14/4

06:50-18:58

2 stops17h 08m

£525

PortlandLondon

PWM - LHR

PWMLHR

Portland

Wed 1/4

12:51-07:10

1 stop13h 19m

London Heathrow

Wed 8/4

11:45-23:59

2 stops17h 14m

£526

PortlandLondon

PWM - LHR

PWMLHR

Portland

Mon 30/3

12:51-10:30

2 stops16h 39m

London Heathrow

Wed 15/4

08:40-00:46

2 stops21h 06m

£530

PortlandLondon

PWM - LHR

PWMLHR

Portland

Tue 24/3

12:51-10:15

2 stops17h 24m

London Heathrow

Tue 31/3

17:35-13:50

2 stops25h 15m

£532

PortlandLondon

PWM - LHR

PWMLHR

Portland

Tue 24/3

17:07-10:00

1 stop12h 53m

London Heathrow

Tue 31/3

15:15-23:37

1 stop13h 22m

£535

PortlandLondon

PWM - LHR

PWMLHR

Portland

Mon 30/3

15:22-10:40

2 stops14h 18m

London Heathrow

Wed 15/4

12:15-18:58

1 stop11h 43m

£540

PortlandLondon

PWM - LHR

PWMLHR

Portland

Mon 6/4

18:18-11:45

1 stop12h 27m

London Heathrow

Wed 15/4

09:30-21:40

2 stops17h 10m

£544

PortlandLondon

PWM - LCY

PWMLCY

Portland

Wed 1/4

12:51-09:30

2 stops15h 39m

London City

Wed 8/4

09:20-23:22

2 stops19h 02m

£551

PortlandLondon

PWM - LHR

PWMLHR

Portland

Thu 9/4

06:00-20:45

1 stop9h 45m

London Heathrow

Wed 15/4

11:55-22:59

1 stop16h 04m

£557

Flights are sorted by cheapest return flights first.

Deals found on 22/2

Showing 1-10 of 56 results
1
2
3
...
6

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 £230). Flying from Portland, Maine to London in June is currently the most expensive (average of £403). 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.

New York (JFK) – chosen by Cheapflights users on 50% 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 £476.

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 24m.

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 JetBlue, United Airlines, or KLM 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?

  • 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 £230). Flying from Portland, Maine to London in June is currently the most expensive (average of £403). 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?

Book flights to London if you plan to visit one of these locations
Milton Keynes
Croydon
Wembley
Luton
Gatwick
Slough
Hounslow
Ilford
Hayes
Brentford
Colchester
Watford
Guildford
Kingston upon Thames
Eastbourne
Ipswich
Chelmsford
Bedford
Romford
Folkestone

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.

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 London?

Cheapflights helps you search for flights from Portland to London via 900+ travel sites so you don’t have to. After performing a flight search, users can also filter their flight selection by filtering for price, number of stops, airlines, and so on.

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.

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.