$320+ Cheap flights from Ontario (ONT) to Heathrow (LHR)
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 11/29. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LHR
Sep 30 — Oct 71
Round-trip
1 adult, Economy
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Find cheap flights from Ontario 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 Ontario to Heathrow
Cheapest
Best
Last-minute
One-way
Cheapest flights from Ontario to HeathrowExplore the most affordable flight options available from Ontario to Heathrow. Find the lowest fares from popular airlines and budget airlines, with prices last updated on August 31, 2026.
Explore the most affordable flight options available from Ontario to Heathrow. Find the lowest fares from popular airlines and budget airlines, with prices last updated on August 31, 2026.
This Gotogate deal was found by Cheapflights users on 8/30. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/16:00 am -
2 stops19h 20m
Sat 1/92:45 pm -
1 stop27h 53m
Deal found 8/30![Multiple Airlines logo]()
$802
This Priceline deal was found by Cheapflights users on 8/29. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/212:00 pm -
1 stop16h 20m
Wed 1/132:45 pm -
1 stop15h 56m
Deal found 8/29![Alaska Airlines logo]()
$809
This Priceline deal was found by Cheapflights users on 8/28. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/1211:05 pm -
1 stop13h 40m
Mon 10/195:00 pm -
1 stop14h 42m
Deal found 8/28![Multiple Airlines logo]()
$810
This Priceline deal was found by Cheapflights users on 8/27. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/26:00 am -
1 stop22h 20m
Wed 12/162:45 pm -
1 stop15h 54m
Deal found 8/27![Alaska Airlines logo]()
$811
This Orbitz deal was found by Cheapflights users on 8/29. 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 Orbitz is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/2210:39 pm -
1 stop14h 06m
Tue 10/205:00 pm -
1 stop25h 17m
Deal found 8/29![Multiple Airlines logo]()
$815
This Priceline deal was found by Cheapflights users on 8/27. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/1311:05 pm -
1 stop13h 40m
Tue 10/205:00 pm -
1 stop25h 17m
Deal found 8/27![Multiple Airlines logo]()
$816
This Expedia deal was found by Cheapflights users on 8/30. 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.
Wed 10/1411:05 pm -
1 stop13h 40m
Wed 10/218:00 pm -
2 stops35h 52m
Deal found 8/30![Multiple Airlines logo]()
$832
This Priceline deal was found by Cheapflights users on 8/26. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/112:45 pm -
1 stop13h 40m
Fri 12/111:50 pm -
1 stop15h 42m
Deal found 8/26![British Airways logo]()
$842
This Priceline deal was found by Cheapflights users on 8/29. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/276:00 am -
1 stop22h 20m
Fri 12/42:45 pm -
1 stop15h 54m
Deal found 8/29![Alaska Airlines logo]()
$859
Best flights from Ontario to HeathrowDiscover carefully curated flight deals from Ontario to Heathrow that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated August 31, 2026.
Discover carefully curated flight deals from Ontario to Heathrow that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated August 31, 2026.
This JetBlue deal was found by Cheapflights users on 8/28. 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 JetBlue is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/2210:39 pm -
1 stop14h 06m
Tue 10/611:55 am -
1 stop16h 35m
Deal found 8/28![JetBlue logo]()
$898
This United Airlines deal was found by Cheapflights users on 8/30. 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 10/111:24 pm -
1 stop12h 16m
Tue 10/2711:35 am -
1 stop16h 16m
Deal found 8/30![United Airlines logo]()
$923
This Alaska Airlines deal was found by Cheapflights users on 8/29. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/202:13 pm -
1 stop16h 52m
Tue 3/162:45 pm -
1 stop14h 54m
Deal found 8/29![Alaska Airlines logo]()
$955
This British Airways deal was found by Cheapflights users on 8/30. 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 10/171:05 pm -
1 stop13h 25m
Mon 10/2610:05 am -
1 stop15h 39m
Deal found 8/30![British Airways logo]()
$1,046
This Icelandair deal was found by Cheapflights users on 8/31. 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 Icelandair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/116:50 am -
2 stops20h 00m
Wed 11/1812:15 pm -
2 stops17h 25m
Deal found 8/31![Multiple Airlines logo]()
$1,123
This JetBlue deal was found by Cheapflights users on 8/28. 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 JetBlue is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/1810:39 pm -
1 stop14h 06m
Fri 9/2511:55 am -
1 stop17h 02m
Deal found 8/28![JetBlue logo]()
$918
This Alaska Airlines deal was found by Cheapflights users on 8/29. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/202:13 pm -
1 stop16h 52m
Thu 3/182:45 pm -
1 stop14h 54m
Deal found 8/29![Alaska Airlines logo]()
$955
This United Airlines deal was found by Cheapflights users on 8/31. 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.
Sat 10/311:35 pm -
1 stop14h 40m
Sun 11/2210:05 am -
1 stop15h 51m
Deal found 8/31![United Airlines logo]()
$1,037
This Alaska Airlines deal was found by Cheapflights users on 8/30. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/152:13 pm -
1 stop16h 52m
Tue 10/272:45 pm -
1 stop26h 32m
Deal found 8/30![Alaska Airlines logo]()
$992
This JetBlue deal was found by Cheapflights users on 8/26. 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 JetBlue is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/1510:39 pm -
1 stop14h 06m
Thu 10/158:15 am -
1 stop21h 57m
Deal found 8/26![JetBlue logo]()
$1,009
This Icelandair deal was found by Cheapflights users on 8/26. 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 Icelandair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/310:05 am -
2 stops16h 45m
Wed 12/1612:15 pm -
2 stops18h 24m
Deal found 8/26![Multiple Airlines logo]()
$1,139
This JetBlue deal was found by Cheapflights users on 8/31. 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 JetBlue is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/1610:39 pm -
1 stop14h 06m
Wed 9/238:15 am -
1 stop20h 42m
Deal found 8/31![JetBlue logo]()
$1,105
Last-minute flights from Ontario to HeathrowDiscover last-minute flight deals from Ontario to Heathrow. Data last updated August 31, 2026 and is based on user searches.
Discover last-minute flight deals from Ontario to Heathrow. Data last updated August 31, 2026 and is based on user searches.
This The Travel House deal was found by Cheapflights users on 8/29. 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 The Travel House is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/1210:39 pm -
1 stop26h 51m
Sat 9/1911:55 am -
1 stop17h 02m
Deal found 8/29![JetBlue logo]()
$910
This Cheapflightsfares deal was found by Cheapflights users on 8/27. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/1510:39 pm -
1 stop14h 06m
Fri 9/258:15 am -
1 stop20h 42m
Deal found 8/27![JetBlue logo]()
$879
This Expedia deal was found by Cheapflights users on 8/27. 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 9/1910:39 pm -
1 stop26h 51m
Sat 9/268:15 am -
1 stop20h 42m
Deal found 8/27![JetBlue logo]()
$900
This JetBlue deal was found by Cheapflights users on 8/26. 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 JetBlue is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/2010:39 pm -
1 stop14h 06m
Wed 9/3011:55 am -
1 stop17h 02m
Deal found 8/26![JetBlue logo]()
$899
This The Travel House deal was found by Cheapflights users on 8/30. 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 The Travel House is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/2110:39 pm -
1 stop14h 06m
Thu 9/2411:55 am -
1 stop17h 02m
Deal found 8/30![JetBlue logo]()
$875
This JetBlue deal was found by Cheapflights users on 8/28. 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 JetBlue is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/2110:39 pm -
1 stop14h 06m
Sat 10/311:55 am -
1 stop17h 02m
Deal found 8/28![JetBlue logo]()
$898
This Orbitz deal was found by Cheapflights users on 8/29. 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 Orbitz is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/2210:39 pm -
1 stop14h 06m
Tue 10/205:00 pm -
1 stop25h 17m
Deal found 8/29![Multiple Airlines logo]()
$815
This Priceline deal was found by Cheapflights users on 8/27. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/2610:39 pm -
1 stop26h 51m
Fri 10/211:55 am -
1 stop17h 02m
Deal found 8/27![JetBlue logo]()
$904
This Cheapflightsfares deal was found by Cheapflights users on 8/29. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/2910:39 pm -
1 stop14h 06m
Wed 10/711:55 am -
1 stop17h 04m
Deal found 8/29![JetBlue logo]()
$878
This Delta deal was found by Cheapflights users on 8/29. 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 9/297:05 am -
1 stop20h 15m
Wed 10/711:45 am -
2 stops20h 10m
Deal found 8/29![Delta logo]()
$908
One-way flights from Ontario to HeathrowSearch for one-way flight options from Ontario to Heathrow. Find affordable one-way fares based on user searches. Data last updated August 31, 2026.
Search for one-way flight options from Ontario to Heathrow. Find affordable one-way fares based on user searches. Data last updated August 31, 2026.
This Booking.com deal was found by Cheapflights users on 8/31. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 11/2910:37 am -
1 stop13h 38m
Deal found 8/31![British Airways logo]()
$320
This Booking.com deal was found by Cheapflights users on 8/31. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 1/52:22 pm -
1 stop13h 38m
Deal found 8/31![British Airways logo]()
$323
This Booking.com deal was found by Cheapflights users on 8/26. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/22:22 pm -
1 stop13h 38m
Deal found 8/26![British Airways logo]()
$324
This Mytrip deal was found by Cheapflights users on 8/31. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 1/202:17 pm -
1 stop13h 43m
Deal found 8/31![British Airways logo]()
$327
This JetBlue deal was found by Cheapflights users on 8/28. 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 JetBlue is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/610:42 pm -
1 stop14h 03m
Deal found 8/28![JetBlue logo]()
$329
This United Airlines deal was found by Cheapflights users on 8/30. 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.
Sat 1/234:03 pm -
1 stop31h 22m
Deal found 8/30![United Airlines logo]()
$335
This FlightHub deal was found by Cheapflights users on 8/27. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/2210:39 pm -
1 stop14h 06m
Deal found 8/27![JetBlue logo]()
$339
This iWofly deal was found by Cheapflights users on 8/29. 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 iWofly is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/1910:39 pm -
1 stop26h 51m
Deal found 8/29![JetBlue logo]()
$347
This JetBlue deal was found by Cheapflights users on 8/28. 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 JetBlue is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/710:42 pm -
1 stop14h 03m
Deal found 8/28![JetBlue logo]()
$349
This United Airlines deal was found by Cheapflights users on 8/29. 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 12/155:45 am -
1 stop20h 30m
Deal found 8/29![United Airlines logo]()
$359
Find flight deals from Ontario to Heathrow
Discover tips and strategies to find the most affordable flight options for your journey from Ontario (ONT) 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 August 31, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $799 (Expedia) |
One-way from | $320 (Booking.com) |
Popular in | June |
Cheapest in | November |
Average price | $1,025 |
Cheapflights Fare Finder
Customize your flight search to find flights from Ontario 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 August 31, 2026.
Use the filters below to find and compare flights from Ontario to London Heathrow Airport that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
OntarioLondon
ONT Ontario - LHR London Heathrow
ONTLHR
Ontario
Tue 9/22
10:39 pm-8:45 pm
1 stop14h 06m
London Heathrow
Tue 10/6
11:55 am-8:30 pm
1 stop16h 35m
$898
OntarioLondon
ONT Ontario - LHR London Heathrow
ONTLHR
Ontario
Fri 9/18
10:39 pm-8:45 pm
1 stop14h 06m
London Heathrow
Fri 9/25
11:55 am-8:57 pm
1 stop17h 02m
$918
Quickest round-trip
OntarioLondon
ONT Ontario - LHR London Heathrow
ONTLHR
Ontario
Sun 10/11
1:24 pm-9:40 am
1 stop12h 16m
London Heathrow
Tue 10/27
11:35 am-8:51 pm
1 stop16h 16m
$923
OntarioLondon
ONT Ontario - LHR London Heathrow
ONTLHR
Ontario
Tue 10/20
2:13 pm-3:05 pm
1 stop16h 52m
London Heathrow
Tue 3/16
2:45 pm-10:39 pm
1 stop14h 54m
$955
OntarioLondon
ONT Ontario - LHR London Heathrow
ONTLHR
Ontario
Tue 10/20
2:13 pm-3:05 pm
1 stop16h 52m
London Heathrow
Thu 3/18
2:45 pm-10:39 pm
1 stop14h 54m
$955
OntarioLondon
ONT Ontario - LHR London Heathrow
ONTLHR
Ontario
Thu 10/15
2:13 pm-3:05 pm
1 stop16h 52m
London Heathrow
Tue 10/27
2:45 pm-10:17 am
1 stop26h 32m
$992
OntarioLondon
ONT Ontario - LHR London Heathrow
ONTLHR
Ontario
Tue 9/15
10:39 pm-8:45 pm
1 stop14h 06m
London Heathrow
Thu 10/15
8:15 am-10:12 pm
1 stop21h 57m
$1,009
OntarioLondon
ONT Ontario - LHR London Heathrow
ONTLHR
Ontario
Sat 10/31
1:35 pm-11:15 am
1 stop14h 40m
London Heathrow
Sun 11/22
10:05 am-5:56 pm
1 stop15h 51m
$1,037
OntarioLondon
ONT Ontario - LHR London Heathrow
ONTLHR
Ontario
Sat 10/17
1:05 pm-10:30 am
1 stop13h 25m
London Heathrow
Mon 10/26
10:05 am-6:44 pm
1 stop15h 39m
$1,046
OntarioLondon
ONT Ontario - LHR London Heathrow
ONTLHR
Ontario
Wed 9/16
10:39 pm-8:45 pm
1 stop14h 06m
London Heathrow
Wed 9/23
8:15 am-8:57 pm
1 stop20h 42m
$1,105
Showing 1-10 of 23 resultsSorted by cheapest first
Compare providers for flights from Ontario 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 Ontario to Heathrow in August.
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy1 star | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy2 stars | Trust Score*1 star | |
| Price Accuracy3 stars | Trust Score*2 stars | |
| Price Accuracy3 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*3 stars |
- Most accurate provider: When it comes to deals on Ontario-London Heathrow Airport flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Ontario-London Heathrow Airport flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Ontario-London Heathrow Airport flight searches over the past month and is updated monthly.
- Most trusted provider: When it comes to deals on Ontario-London Heathrow Airport flights, Cheapflights users trust FlightHub the most. FlightHub 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 Ontario-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 Ontario to Heathrow
Have a flexible travel schedule? Discover the best time to fly to Heathrow from Ontario with our price prediction graph.
ONT-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.
Cheapflights Insights
Everything you need to know about your flight from Ontario to London Heathrow Airport
What is the cheapest month to book a flight from Ontario to London Heathrow Airport?
Currently, November is the cheapest month in which you can book a flight from Ontario to London Heathrow Airport (average of $665). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of $1,592). 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 to fly round-trip from Ontario to London Heathrow Airport?
Airfare is below average for this route at the moment.
Ontario to London Heathrow Airport flights typically cost between $911 and $1,146 in February.The cheapest round-trip price found within the last 5 days was $799 on Alaska Airlines (Feb 9-Feb 23).
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 August 31, 2026.
Read through reviews of airlines operating flights from Ontario to London Heathrow Airport, such as Alaska Airlines,Delta, andUnited Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Boarding
8.1
Entertainment
7.0
Overall
7.9
Crew
8.5
Comfort
7.8
Food
7.0
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
Boarding
8.1
Entertainment
7.0
Overall
7.9
Crew
8.5
Comfort
7.8
Food
7.0
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
Boarding
8.1
Entertainment
7.0
Overall
7.9
Crew
8.5
Comfort
7.8
Food
7.0
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
Boarding
8.1
Entertainment
7.0
Overall
7.9
Crew
8.5
Comfort
7.8
Food
7.0
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
Boarding
8.1
Entertainment
7.0
Overall
7.9
Crew
8.5
Comfort
7.8
Food
7.0
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
Boarding
8.1
Entertainment
7.0
Overall
7.9
Crew
8.5
Comfort
7.8
Food
7.0
Reviews
1 / 20
6.0
GoodAnonymous,Jul 2026
SEA - LHR
Related info for your journey
Find useful and relevant information for your journey from Ontario 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
Winchester
Gatwick
Hounslow
Harrow
Eastleigh
Wembley
Southend-on-Sea
Basingstoke
Watford
Northampton
Dartford
Croydon
Chipping Norton
Kingston upon Thames
Eastbourne
Slough
Stansted
Sutton
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Top 5 airlines flying from Ontario to Heathrow
Discover the top 5 airlines that operate flights from Ontario 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 August 31, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$469 | Average$924 | FlexibilityNo cancel fee | On-time72% | |
| Cheapest$572 | Average$895 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$615 | Average$872 | FlexibilityNo cancel fee | On-time70% | |
| Cheapest$665 | Average$1,177 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$806 | Average$1,592 | FlexibilityNo cancel fee | On-time75% |