$321+ Cheap flights from Portland, ME (PWM) to Heathrow (LHR)
This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 11/22. Fares are subject to change and may not be available on all flights or dates of travel.
PWM — LHR
Oct 10 — Oct 171
Round-trip
1 adult, Economy
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Find cheap flights from Portland to Heathrow with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheap flight deals from Portland to Heathrow
Cheapest
Best
Last-minute
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Cheapest flights from Portland to HeathrowExplore 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 September 10, 2026.
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 September 10, 2026.
This Delta deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/76:04 am -
1 stop19h 16m
Wed 10/1411:30 am -
2 stops17h 40m
Deal found 9/10![Delta logo]()
$739
This United Airlines deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/168:49 am -
1 stop19h 21m
Wed 11/186:50 am -
2 stops21h 31m
Deal found 9/9![United Airlines logo]()
$759
This United Airlines deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/102:05 pm -
2 stops14h 05m
Thu 11/126:50 am -
2 stops17h 12m
Deal found 9/10![United Airlines logo]()
$764
This United Airlines deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/95:08 pm -
1 stop33h 47m
Thu 11/126:50 am -
2 stops17h 12m
Deal found 9/10![United Airlines logo]()
$765
This Delta deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/244:03 pm -
2 stops16h 47m
Thu 12/310:00 am -
2 stops18h 53m
Deal found 9/9![Delta logo]()
$770
This Air Canada deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/108:49 am -
3 stops18h 41m
Thu 11/126:00 am -
3 stops22h 21m
Deal found 9/10![Air Canada logo]()
$784
This Delta deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/86:28 am -
1 stop18h 52m
Mon 10/1211:45 am -
2 stops40h 33m
Deal found 9/9![Delta logo]()
$789
This Delta deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/254:15 pm -
1 stop10h 05m
Sun 11/110:50 am -
1 stop15h 10m
Deal found 9/10![Delta logo]()
$796
This Delta deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/244:20 pm -
1 stop9h 55m
Sun 9/276:30 am -
2 stops22h 26m
Deal found 9/10![Delta logo]()
$839
Best flights from Portland to HeathrowDiscover carefully curated flight deals from Portland to Heathrow that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 10, 2026.
Discover carefully curated flight deals from Portland to Heathrow that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 10, 2026.
This Delta deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/244:03 pm -
1 stop11h 32m
Thu 12/38:55 am -
2 stops20h 26m
Deal found 9/9![Delta logo]()
$739
This United Airlines deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/168:49 am -
1 stop19h 21m
Wed 11/186:50 am -
2 stops21h 31m
Deal found 9/9![United Airlines logo]()
$759
This United Airlines deal was found by Cheapflights users on 9/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/103:41 pm -
1 stop13h 44m
Tue 11/176:50 am -
2 stops21h 31m
Deal found 9/7![United Airlines logo]()
$866
This United Airlines deal was found by Cheapflights users on 9/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/2011:35 am -
1 stop14h 10m
Tue 10/276:50 am -
2 stops16h 12m
Deal found 9/5![United Airlines logo]()
$866
This United Airlines deal was found by Cheapflights users on 9/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/103:41 pm -
2 stops14h 09m
Tue 11/246:50 am -
2 stops17h 12m
Deal found 9/8![United Airlines logo]()
$871
This United Airlines deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/255:50 am -
1 stop24h 35m
Sun 11/17:30 am -
2 stops16h 32m
Deal found 9/9![United Airlines logo]()
$878
This United Airlines deal was found by Cheapflights users on 9/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/63:41 pm -
2 stops13h 59m
Tue 10/139:30 am -
2 stops15h 52m
Deal found 9/8![United Airlines logo]()
$882
This United Airlines deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/283:40 pm -
2 stops15h 10m
Mon 11/26:50 am -
2 stops17h 12m
Deal found 9/9![United Airlines logo]()
$894
Last-minute flights from Portland to HeathrowDiscover last-minute flight deals from Portland to Heathrow. Data last updated September 10, 2026 and is based on user searches.
Discover last-minute flight deals from Portland to Heathrow. Data last updated September 10, 2026 and is based on user searches.
This Delta deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/244:20 pm -
1 stop9h 55m
Sun 9/276:30 am -
2 stops22h 26m
Deal found 9/10![Delta logo]()
$839
This Delta deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/76:04 am -
1 stop19h 16m
Wed 10/1411:30 am -
2 stops17h 40m
Deal found 9/10![Delta logo]()
$739
This Delta deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/86:28 am -
1 stop18h 52m
Mon 10/1211:45 am -
2 stops40h 33m
Deal found 9/9![Delta logo]()
$789
This Air Canada deal was found by Cheapflights users on 9/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/106:00 am -
2 stops34h 00m
Wed 10/289:00 am -
2 stops42h 21m
Deal found 9/6![Air Canada logo]()
$872
This United Airlines deal was found by Cheapflights users on 9/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/146:00 am -
2 stops21h 35m
Wed 10/286:50 am -
2 stops16h 12m
Deal found 9/8![United Airlines logo]()
$867
This United Airlines deal was found by Cheapflights users on 9/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/206:00 am -
1 stop10h 25m
Tue 10/276:50 am -
2 stops16h 12m
Deal found 9/6![United Airlines logo]()
$858
This Delta deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/254:15 pm -
1 stop10h 05m
Sun 11/110:50 am -
1 stop15h 10m
Deal found 9/10![Delta logo]()
$796
One-way flights from Portland to HeathrowSearch for one-way flight options from Portland to Heathrow. Find affordable one-way fares based on user searches. Data last updated September 10, 2026.
Search for one-way flight options from Portland to Heathrow. Find affordable one-way fares based on user searches. Data last updated September 10, 2026.
This Expedia deal was found by Cheapflights users on 9/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/225:50 am -
2 stops34h 10m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/8![Air Canada logo]()
$321
This deal was found by Cheapflights users on 9/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/186:00 am -
1 stop9h 45m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/7![JetBlue logo]()
$329
This United Airlines deal was found by Cheapflights users on 9/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/255:30 am -
1 stop21h 10m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/7![United Airlines logo]()
$333
This United Airlines deal was found by Cheapflights users on 9/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/2211:35 am -
1 stop14h 10m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/7![United Airlines logo]()
$336
This Air Canada deal was found by Cheapflights users on 9/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/228:03 am -
3 stops17h 27m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/7![Air Canada logo]()
$344
This Air Canada deal was found by Cheapflights users on 9/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/278:49 am -
3 stops17h 21m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/8![Air Canada logo]()
$345
This Expedia deal was found by Cheapflights users on 9/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/216:00 am -
2 stops34h 00m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/8![Air Canada logo]()
$347
This British Airways deal was found by Cheapflights users on 9/8. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure British Airways is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/213:22 pm -
1 stop13h 38m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/8![Multiple Airlines logo]()
$359
This Kiwi.com deal was found by Cheapflights users on 9/7. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/255:28 pm -
3 stops44h 02m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/7![Multiple Airlines logo]()
$953
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 September 10, 2026.
Most accurate provider | Ovago 3 stars |
|---|---|
Most trusted provider | Ovago 3 stars |
Round-trip from | $739 (Delta) |
One-way from | $321 (Expedia) |
Popular in | June |
Cheapest in | February |
Average price | $1,171 |
Cheapflights Fare Finder
Customize 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 7,457,451 searches. Data last updated September 10, 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
Cheapest round-trip
PortlandLondon
PWM Portland - LHR London Heathrow
PWMLHR
Portland
Fri 11/27
5:08 pm-12:00 pm
1 stop13h 52m
London Heathrow
Wed 12/31
12:00 am-6:00 pm
Nonstop0h 00m
$333
PortlandLondon
PWM Portland - LHR London Heathrow
PWMLHR
Portland
Sun 10/25
5:30 am-6:40 am
1 stop21h 10m
London Heathrow
Wed 12/31
12:00 am-6:00 pm
Nonstop0h 00m
$333
PortlandLondon
PWM Portland - LHR London Heathrow
PWMLHR
Portland
Thu 10/22
11:35 am-6:45 am
1 stop14h 10m
London Heathrow
Wed 12/31
12:00 am-6:00 pm
Nonstop0h 00m
$336
PortlandLondon
PWM Portland - LHR London Heathrow
PWMLHR
Portland
Sun 11/22
10:50 am-9:20 pm
1 stop29h 30m
London Heathrow
Wed 12/31
12:00 am-6:00 pm
Nonstop0h 00m
$344
PortlandLondon
PWM Portland - LHR London Heathrow
PWMLHR
Portland
Fri 11/27
8:49 am-7:10 am
3 stops17h 21m
London Heathrow
Wed 12/31
12:00 am-6:00 pm
Nonstop0h 00m
$345
Quickest round-trip
PortlandLondon
PWM Portland - LHR London Heathrow
PWMLHR
Portland
Sat 11/21
3:22 pm-10:00 am
1 stop13h 38m
London Heathrow
Wed 12/31
12:00 am-6:00 pm
Nonstop0h 00m
$359
PortlandLondon
PWM Portland - LHR London Heathrow
PWMLHR
Portland
Tue 11/24
4:03 pm-8:35 am
1 stop11h 32m
London Heathrow
Thu 12/3
8:55 am-12:21 am
2 stops20h 26m
$739
PortlandLondon
PWM Portland - LHR London Heathrow
PWMLHR
Portland
Mon 11/16
8:49 am-9:10 am
1 stop19h 21m
London Heathrow
Wed 11/18
6:50 am-11:21 pm
2 stops21h 31m
$759
PortlandLondon
PWM Portland - LHR London Heathrow
PWMLHR
Portland
Tue 11/10
3:41 pm-10:25 am
1 stop13h 44m
London Heathrow
Tue 11/17
6:50 am-11:21 pm
2 stops21h 31m
$866
PortlandLondon
PWM Portland - LHR London Heathrow
PWMLHR
Portland
Tue 10/20
11:35 am-6:45 am
1 stop14h 10m
London Heathrow
Tue 10/27
6:50 am-7:02 pm
2 stops16h 12m
$866
Showing 1-10 of 16 resultsSorted by cheapest first
Compare providers for flights from Portland to Heathrow
Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Portland to Heathrow in September.
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars |
- Most accurate provider: When it comes to deals on Portland, Maine-London Heathrow Airport flights, users find the pricing of Ovago to be most consistent on Cheapflights vs. Ovago Users can find the same prices on Portland, Maine-London Heathrow Airport flight deals on Cheapflights vs. Ovago >95% of the time. Price accuracy is based on data collected from Portland, Maine-London Heathrow Airport flight searches over the past month and is updated monthly.
- Most trusted provider: When it comes to deals on Portland, Maine-London Heathrow Airport flights, Cheapflights users trust Ovago the most. Ovago has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Portland, Maine-London Heathrow Airport flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.
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.
PWM-LHR
Estimated round-trip 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.
Reviews of airlines servicing Heathrow
Get insights into the airlines that provide service to Heathrow. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Heathrow. Reviews last updated September 10, 2026.
Read through reviews of airlines operating flights from Portland to London Heathrow Airport, such as United Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Entertainment
7.1
Comfort
7.3
Crew
8.1
Boarding
7.7
Overall
7.4
Food
6.7
Reviews
1 / 20
4.0
OkayChris,Aug 2026
MIA - ORD
Entertainment
7.1
Comfort
7.3
Crew
8.1
Boarding
7.7
Overall
7.4
Food
6.7
Reviews
1 / 20
4.0
OkayChris,Aug 2026
MIA - ORD
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.
Traveling to a place near London Heathrow Airport?
Book flights to London Heathrow Airport if you plan to visit one of these locationsIlford
Dorking
Gatwick
Hounslow
Harrow
Wembley
Southend-on-Sea
Basingstoke
Watford
Northampton
Dartford
Winchester
Croydon
Chipping Norton
Kingston upon Thames
Eastbourne
Slough
Stansted
Sutton
Luton
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Other flights to Heathrow
Explore flights to Heathrow departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on September 10, 2026.
Portland and Heathrow flights
Browse other Portland and Heathrow flight options. Last updated on September 10, 2026.
Other flights from Portland
Browse through other flights departing from Portland. Flights are based on user searches made on Cheapflights and were last updated on September 10, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Top airline flying from Portland to Heathrow
Discover the top airline that operate flights from Portland to Heathrow. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 7,457,451 searches. Data last updated September 10, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$752 | Average$1,192 | FlexibilityNo cancel fee | On-time69% |