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Heathrow

$336+ 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 2/28. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LHR
Feb 20 — Feb 271
Fri 2/20
Fri 2/27
1 adult, Economy
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Find cheap flights from Ontario to Heathrow with Cheapflights

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Cheap flight deals from Ontario to Heathrow

Cheapest flights from Ontario to Heathrow
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 January 21, 2026.

This Iberia deal was found by Cheapflights users on 1/20. 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 Iberia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/47:00 am
ONT
-
LHR
1 stop17h 35m
Iberia
Wed 3/116:15 am
LHR
-
ONT
2 stops23h 15m
Iberia
Deal found 1/20$580
This Iberia deal was found by Cheapflights users on 1/19. 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 Iberia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/232:31 pm
ONT
-
LHR
1 stop15h 54m
Iberia
Tue 9/88:50 pm
LHR
-
ONT
2 stops33h 00m
Iberia
Deal found 1/19$594
This Iberia deal was found by Cheapflights users on 1/19. 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 Iberia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/246:00 am
ONT
-
LHR
1 stop19h 15m
Iberia
Thu 4/1611:30 am
LHR
-
ONT
2 stops20h 16m
Iberia
Deal found 1/19$596
This Cheapflightsfares deal was found by Cheapflights users on 1/18. 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.
Mon 2/24:45 pm
ONT
-
LHR
1 stop12h 30m
British Airways
Thu 2/264:30 pm
LHR
-
ONT
1 stop15h 29m
British Airways
Deal found 1/18$599
This oojo deal was found by Cheapflights users on 1/19. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 2/155:02 pm
ONT
-
LHR
1 stop12h 13m
British Airways
Fri 2/272:45 pm
LHR
-
ONT
1 stop15h 44m
British Airways
Deal found 1/19$601
This Iberia deal was found by Cheapflights users on 1/20. 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 Iberia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 2/197:00 am
ONT
-
LHR
1 stop17h 15m
Iberia
Thu 2/268:50 pm
LHR
-
ONT
2 stops33h 39m
Iberia
Deal found 1/20$602
This Cheapflightsfares deal was found by Cheapflights users on 1/20. 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.
Wed 2/113:09 pm
ONT
-
LHR
1 stop13h 06m
British Airways
Wed 2/1811:45 am
LHR
-
ONT
1 stop16h 00m
British Airways
Deal found 1/20$604
This oojo deal was found by Cheapflights users on 1/21. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 3/37:00 am
ONT
-
LHR
1 stop15h 50m
British Airways
Tue 3/1010:15 am
LHR
-
ONT
1 stop15h 27m
British Airways
Deal found 1/21$606
This Expedia deal was found by Cheapflights users on 1/20. 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 1/3110:58 am
ONT
-
LHR
1 stop35h 52m
Iberia
Tue 3/318:55 am
LHR
-
ONT
1 stop21h 54m
Iberia
Deal found 1/20$613
This Cheapflightsfares deal was found by Cheapflights users on 1/19. 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.
Thu 2/192:39 pm
ONT
-
LHR
1 stop13h 01m
British Airways
Thu 2/264:30 pm
LHR
-
ONT
1 stop15h 29m
British Airways
Deal found 1/19$614
This Cheapflightsfares deal was found by Cheapflights users on 1/19. 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 3/3110:56 am
ONT
-
LHR
1 stop13h 09m
British Airways
Thu 4/1610:05 am
LHR
-
ONT
1 stop14h 17m
British Airways
Deal found 1/19$615

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 January 21, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

Expedia
3 stars

Round-trip from

$580
(Iberia)

One-way from

$336
(Kiwi.com)

Popular in

June

Cheapest in

November

Average price

$1,052
Provider with most accurate pricing for Ontario-London Heathrow flight deals.
Search Deals
Provider most trusted by Cheapflights users for Ontario-London Heathrow flights.
Search Deals
From Ontario to London Heathrow
Search Deals
One-way flight from Ontario to London Heathrow
Search Deals
Highest demand for flights based on searches. 23% potential increase in price ($252 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 5% potential price decrease ($45 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in January 2026
Search Deals

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 2,558,603 searches. Data last updated January 21, 2026.
Use the filters below to find and compare flights from Ontario to London Heathrow Airport that are best for you.

Fly from

Ontario

Fly to

Heathrow

Route

Depart

Return

Price

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 2/8

4:45 pm-1:15 pm

1 stop12h 30m

London Heathrow

Fri 2/27

2:25 pm-10:07 pm

1 stop15h 42m

$608

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 3/24

10:56 am-8:15 am

1 stop14h 19m

London Heathrow

Tue 3/31

8:55 am-4:22 pm

1 stop15h 27m

$608

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 2/4

3:09 pm-12:15 pm

1 stop13h 06m

London Heathrow

Fri 2/27

4:30 pm-11:59 pm

1 stop15h 29m

$608

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 3/25

10:56 am-6:50 am

1 stop12h 54m

London Heathrow

Thu 4/2

2:25 pm-10:30 pm

1 stop16h 05m

$624

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 3/21

11:58 pm-6:50 am

1 stop23h 52m

London Heathrow

Thu 4/16

8:55 am-6:37 pm

1 stop17h 42m

$624

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 3/23

11:58 pm-8:15 am

1 stop25h 17m

London Heathrow

Tue 4/14

10:05 am-4:22 pm

1 stop14h 17m

$629

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Thu 3/5

7:30 am-11:55 am

1 stop20h 25m

London Heathrow

Thu 3/12

6:30 am-9:00 pm

2 stops21h 30m

$630

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 3/24

1:40 pm-12:00 pm

1 stop15h 20m

London Heathrow

Wed 4/15

8:40 am-10:45 pm

2 stops22h 05m

$646

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Thu 3/5

7:30 am-10:30 am

1 stop19h 00m

London Heathrow

Thu 3/12

10:45 am-9:04 pm

1 stop17h 19m

$649

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 4/15

6:00 am-7:10 am

2 stops17h 10m

London Heathrow

Tue 5/5

11:45 am-10:37 pm

2 stops18h 52m

$650

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/19

Showing 1-10 of 23 results
1
2
3

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 January.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy2 starsTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*1 star
CheapflightsfaresPrice Accuracy3 starsTrust Score*2 stars
Thrive TravelPrice Accuracy3 starsTrust Score*1 star
AranGrantPrice Accuracy2 starsTrust Score*3 stars
OvagoPrice Accuracy2 starsTrust Score*2 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • 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 Expedia the most. Expedia 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.
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

How far ahead should I book a flight from Ontario to London Heathrow Airport?

Use this chart to determine the optimal time to book a round-trip flight from Ontario to Heathrow. Price data was last updated on January 16, 2026.

The price you pay for your flight from Ontario to London Heathrow Airport may vary depending on when you book. For the best chance of a lower fare, look to book 62 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

What is the cheapest month to book a flight from Ontario to London Heathrow Airport?

Currently, December is the cheapest month in which you can book a flight from Ontario to London Heathrow Airport (average of $469). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of $699). 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.

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 January 21, 2026.
Read through reviews of airlines operating flights from Ontario to London Heathrow Airport, such as Delta, United Airlines, and American Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Delta
7.9
Good
8,087 reviews

Food

7.2

Crew

8.5

Overall

7.9

Comfort

7.9

Boarding

8.1

Entertainment

7.8

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
Delta
7.9
Good
8,087 reviews
Delta
7.9
Good
8,087 reviews

Food

7.2

Crew

8.5

Overall

7.9

Comfort

7.9

Boarding

8.1

Entertainment

7.8

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
United Airlines
7.4
Good
9,190 reviews
Delta
7.9
Good
8,087 reviews

Food

7.2

Crew

8.5

Overall

7.9

Comfort

7.9

Boarding

8.1

Entertainment

7.8

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
American Airlines
7.2
Good
11,173 reviews
Delta
7.9
Good
8,087 reviews

Food

7.2

Crew

8.5

Overall

7.9

Comfort

7.9

Boarding

8.1

Entertainment

7.8

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
Iberia
7.0
Good
3,094 reviews
Delta
7.9
Good
8,087 reviews

Food

7.2

Crew

8.5

Overall

7.9

Comfort

7.9

Boarding

8.1

Entertainment

7.8

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
British Airways
6.7
Okay
7,689 reviews
Delta
7.9
Good
8,087 reviews

Food

7.2

Crew

8.5

Overall

7.9

Comfort

7.9

Boarding

8.1

Entertainment

7.8

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

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.

  • What airport do you fly from for flights from Ontario to London Heathrow?

    If you book a flight to London Heathrow from Ontario, you will be flying from Ontario, which is the city’s only airport. Ontario (ONT) is located 3.1 mi from the center of Ontario. There are 0 flights from Ontario to London Heathrow per day from 6 different airlines.

  • How long is the flight from Ontario to London Heathrow Airport?

    British Airways can get you from Ontario to London Heathrow Airport in just under 12h 30m. Your travel time can differ by up to . The distance between Ontario and London Heathrow Airport is about 5407 mi.

  • What are the cheapest airlines flying from Ontario to London Heathrow Airport round-trip?

    According to our current data, Delta ($570), KLM ($580), and Iberia ($615) offers the cheapest pricing from Ontario to London Heathrow Airport. Delta is 32% cheaper than the average price of flights available within the next 90 days to this destination.

  • Can I find deals for flights from Ontario to Heathrow that include hotel bookings?

    Yes. In addition to deals on Ontario to Heathrow flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Ontario to Heathrow?

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

  • Can I find deals for business class flights from Ontario to Heathrow?

    Yes. Cheapflights offers flight deals from Ontario to Heathrow 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 Ontario to London Heathrow Airport?

    Currently, December is the cheapest month in which you can book a flight from Ontario to London Heathrow Airport (average of $469). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of $699). 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

Traveling to a place near London Heathrow Airport?

Book flights to London Heathrow Airport if you plan to visit one of these locations
Ilford
Hounslow
Southend-on-Sea
Harrow
Croydon
Eastleigh
Gatwick
Dartford
Dover
Winchester
Orpington
Watford
Northampton
Hayes
Borehamwood
Broadway
Aylesbury
Chipping Norton
Horley
Kingston upon Thames

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Top 6 airlines flying from Ontario to Heathrow

Discover the top 6 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 2,558,603 searches. Data last updated January 21, 2026.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$570Average$672FlexibilityNo cancel feeOn-timeN/A
KLMCheapest$580Average$653FlexibilityNo cancel feeOn-time75%
IberiaCheapest$615Average$713FlexibilityNo cancel feeOn-time77%
British AirwaysCheapest$624Average$756FlexibilityNo cancel feeOn-time70%
American AirlinesCheapest$624Average$744FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$662Average$842FlexibilityNo cancel feeOn-time69%

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