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$294+ 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 1/13. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LHR
dic. 6 — dic. 131
sáb. 12/6
sáb. 12/13
1 adult, Economy
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Cheapflights Tip: The best prices from Ontario to London Heathrow are usually found in September or February, booked 62 days in advance, depart on a Wednesday or Sunday and return on a Tuesday

Cheap 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 noviembre 6, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$585
(Netflights)

One-way from

$294
(Kiwi.com)

Popular in

June

Cheapest in

September

Average price

$845
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. 22% potential increase in price ($252 potential increase over avg. RT price).
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Cheapest flight prices on average. 5% potential price decrease ($42 potential savings vs. average RT price).
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Average for round-trip flights in November 2025
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Find 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 noviembre 6, 2025.

This Netflights deal was found by Cheapflights users on 11/6. 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 Netflights is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mar. 12/27:05 amONT - LHR
1 stop15h 20mVirgin Atlantic
mar. 12/162:45 pmLHR - ONT
1 stop16h 02mVirgin Atlantic
Deal found 11/6$585
This Delta deal was found by Cheapflights users on 11/5. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 12/36:00 amONT - LHR
1 stop20h 00mDelta
mié. 12/106:30 amLHR - ONT
2 stops18h 37mDelta
Deal found 11/5$608
This Delta deal was found by Cheapflights users on 11/6. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
dom. 11/912:16 pmONT - LHR
1 stop15h 24mDelta
mar. 11/258:55 amLHR - ONT
1 stop18h 47mDelta
Deal found 11/6$615
This Delta deal was found by Cheapflights users on 11/6. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 12/410:25 pmONT - LHR
1 stop24h 00mDelta
jue. 12/116:30 amLHR - ONT
2 stops18h 37mDelta
Deal found 11/6$618
This Delta deal was found by Cheapflights users on 11/5. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mar. 11/187:05 amONT - LHR
1 stop16h 45mDelta
jue. 11/276:30 amLHR - ONT
2 stops21h 12mDelta
Deal found 11/5$619
This Iberia deal was found by Cheapflights users on 11/6. 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 Iberia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
dom. 11/912:53 pmONT - LHR
1 stop13h 07mIberia
mar. 11/254:30 pmLHR - ONT
1 stop15h 27mIberia
Deal found 11/6$622
This KLM deal was found by Cheapflights users on 11/5. 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 KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mar. 11/187:05 amONT - LHR
1 stop20h 35mKLM
jue. 11/2710:45 amLHR - ONT
1 stop16h 57mKLM
Deal found 11/5$625
This Iberia deal was found by Cheapflights users on 11/4. 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.
mar. 11/1810:47 amONT - LHR
1 stop13h 48mIberia
mar. 11/254:30 pmLHR - ONT
1 stop15h 27mIberia
Deal found 11/4$626

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 noviembre 6, 2025.
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

lun. 1/5

3:30 pm-12:50 pm

1 stop13h 20m

London Heathrow

mar. 1/20

8:40 am-9:07 pm

2 stops20h 27m

$616

OntarioLondon

ONT - LHR

ONTLHR

Ontario

vie. 1/9

7:30 am-10:30 am

1 stop19h 00m

London Heathrow

dom. 1/18

6:30 am-10:29 pm

2 stops23h 59m

$626

OntarioLondon

ONT - LHR

ONTLHR

Ontario

mar. 12/2

6:00 am-10:00 am

1 stop20h 00m

London Heathrow

mar. 12/16

11:05 am-11:04 pm

2 stops19h 59m

$630

OntarioLondon

ONT - LHR

ONTLHR

Ontario

vie. 2/27

6:00 am-10:00 am

1 stop20h 00m

London Heathrow

mar. 3/3

6:30 am-10:40 pm

2 stops24h 10m

$638

OntarioLondon

ONT - LHR

ONTLHR

Ontario

jue. 1/22

10:58 am-8:35 am

1 stop13h 37m

London Heathrow

mar. 1/27

3:00 pm-10:48 pm

1 stop15h 48m

$644

OntarioLondon

ONT - LHR

ONTLHR

Ontario

mié. 1/14

3:09 pm-12:15 pm

1 stop13h 06m

London Heathrow

dom. 1/18

2:20 pm-10:13 pm

1 stop15h 53m

$644

OntarioLondon

ONT - LHR

ONTLHR

Ontario

lun. 1/19

1:10 pm-10:00 am

1 stop12h 50m

London Heathrow

dom. 1/25

10:45 am-4:13 pm

1 stop13h 28m

$644

OntarioLondon

ONT - LHR

ONTLHR

Ontario

jue. 12/4

1:34 pm-9:40 am

1 stop12h 06m

London Heathrow

vie. 12/12

10:05 am-5:37 pm

1 stop15h 32m

$646

OntarioLondon

ONT - LHR

ONTLHR

Ontario

jue. 1/8

6:00 am-12:00 pm

1 stop22h 00m

$399

OntarioLondon

ONT - LHR

ONTLHR

Ontario

dom. 1/11

6:39 pm-8:35 pm

2 stops17h 56m

$399

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/5

Showing 1-10 of 17 results
1
2

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 November.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy2 starsTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*1 star
eDreamsPrice Accuracy3 starsTrust Score*3 stars
AranGrantPrice Accuracy2 starsTrust Score*3 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 eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on Ontario-London Heathrow Airport flight deals on Cheapflights vs. eDreams >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 eDreams the most. eDreams 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 October 31, 2025.

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, January is the cheapest month in which you can book a flight from Ontario to London Heathrow Airport (average of $437). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of $700). 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 is the cheapest time of day to fly from ONT to LHR?

Find hourly flight availability from Ontario to Heathrow. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated noviembre 6, 2025.

It’s typically best to fly out from Ontario to London Heathrow Airport in the morning. Doing so could potentially save you 31% on the flight price compared to flying in the evening, which is usually more expensive.

What is the cheapest day to fly from Ontario to London Heathrow Airport?

Use this chart to determine the cheapest time to fly round-trip from Ontario to Heathrow. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Ontario to London Heathrow Airport flight should consider departing on Tuesday mornings when fares are most often at their lowest. Sunday evenings flights should be avoided if possible as fares are typically the most expensive at this time.

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 noviembre 6, 2025.
Read through reviews of airlines operating flights from Ontario to London Heathrow Airport, such as Delta, KLM, and United Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Delta
7.9
Good
8,004 reviews

Overall

7.9

Food

7.3

Crew

8.5

Boarding

8.2

Comfort

7.9

Entertainment

7.9

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
8,004 reviews
Delta
7.9
Good
8,004 reviews

Overall

7.9

Food

7.3

Crew

8.5

Boarding

8.2

Comfort

7.9

Entertainment

7.9

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.
KLM
7.7
Good
1,405 reviews
Delta
7.9
Good
8,004 reviews

Overall

7.9

Food

7.3

Crew

8.5

Boarding

8.2

Comfort

7.9

Entertainment

7.9

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
9,003 reviews
Delta
7.9
Good
8,004 reviews

Overall

7.9

Food

7.3

Crew

8.5

Boarding

8.2

Comfort

7.9

Entertainment

7.9

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
11,041 reviews
Delta
7.9
Good
8,004 reviews

Overall

7.9

Food

7.3

Crew

8.5

Boarding

8.2

Comfort

7.9

Entertainment

7.9

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
7,496 reviews
Delta
7.9
Good
8,004 reviews

Overall

7.9

Food

7.3

Crew

8.5

Boarding

8.2

Comfort

7.9

Entertainment

7.9

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?

    Delta can get you from Ontario to London Heathrow Airport in just under 13h 20m. 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 ($572), KLM ($580), and Iberia ($615) offers the cheapest pricing from Ontario to London Heathrow Airport. Delta is 33% 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, January is the cheapest month in which you can book a flight from Ontario to London Heathrow Airport (average of $437). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of $700). 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
Hounslow
Ilford
Hayes
Southend-on-Sea
Harrow
Croydon
Eastleigh
Dartford
Dover
Winchester
Orpington
Northampton
Gatwick
Borehamwood
Broadway
Aylesbury
Bedford
Chipping Norton
Wembley
Folkestone

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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 noviembre 6, 2025.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$572Average$673FlexibilityNo cancel feeOn-timeN/A
KLMCheapest$580Average$672FlexibilityNo cancel feeOn-time75%
IberiaCheapest$615Average$713FlexibilityNo cancel feeOn-time77%
American AirlinesCheapest$650Average$957FlexibilityNo cancel feeOn-time71%
British AirwaysCheapest$662Average$867FlexibilityNo cancel feeOn-time70%
United AirlinesCheapest$677Average$819FlexibilityNo cancel feeOn-time69%

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