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$322+ 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 10/1. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LHR
Jun 17 — Jun 241
Tue 6/17
Tue 6/24
1 adult, Economy
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Cheapflights Tip: The best prices from Ontario to London Heathrow are usually found in March or October, booked 52 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 June 12, 2025.

Round-trip from

$609
(Delta)

One-way from

$322
(Trip.com)

Popular in

June

Cheapest in

March

Average price

$1,317
From Ontario to London Heathrow
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One-way flight from Ontario to London Heathrow
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Highest demand for flights based on searches. 23% potential increase in price ($259 potential increase over avg. RT price).
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Cheapest flight prices on average. 5% potential price decrease ($44 potential savings vs. average RT price).
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Average for round-trip flights in June 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 June 12, 2025.

This Delta deal was found by Cheapflights users on 6/12. 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 7/151:15 pmONT - LHR
1 stop12h 35mDelta
Wed 7/305:25 pmLHR - ONT
1 stop25h 00mDelta
Deal found 6/12$609
This Iberia deal was found by Cheapflights users on 6/11. 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 10/52:30 pmONT - LHR
1 stop15h 55mIberia
Tue 10/146:10 amLHR - ONT
2 stops25h 52mIberia
Deal found 6/11$657
This Priceline deal was found by Cheapflights users on 6/10. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/122:57 pmONT - LHR
1 stop15h 28mBritish Airways
Tue 9/211:30 amLHR - ONT
2 stops19h 18mBritish Airways
Deal found 6/10$659
This Expedia deal was found by Cheapflights users on 6/10. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/125:05 amONT - LHR
2 stops17h 25mAir Canada
Tue 9/25:40 pmLHR - ONT
2 stops26h 52mAir Canada
Deal found 6/10$664
This United Airlines deal was found by Cheapflights users on 6/12. 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.
Fri 8/86:39 pmONT - LHR
2 stops51h 51mUnited Airlines
Fri 8/2212:05 pmLHR - ONT
2 stops32h 08mUnited Airlines
Deal found 6/12$669
This American Airlines deal was found by Cheapflights users on 6/11. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/34:45 pmONT - LHR
1 stop12h 05mAmerican Airlines
Tue 8/1911:15 amLHR - ONT
1 stop14h 37mAmerican Airlines
Deal found 6/11$672
This Virgin Atlantic deal was found by Cheapflights users on 6/12. 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 Virgin Atlantic is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/42:14 pmONT - LHR
2 stops18h 01mVirgin Atlantic
Tue 8/1211:20 amLHR - ONT
2 stops20h 20mVirgin Atlantic
Deal found 6/12$694
This KLM deal was found by Cheapflights users on 6/11. 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.
Sun 11/1612:00 pmONT - LHR
1 stop14h 35mKLM
Fri 11/282:20 pmLHR - ONT
1 stop16h 21mKLM
Deal found 6/11$696
This JetBlue deal was found by Cheapflights users on 6/12. 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 9/810:56 pmONT - LHR
1 stop13h 49mJetBlue
Wed 9/178:15 amLHR - ONT
1 stop21h 14mJetBlue
Deal found 6/12$751
This CheapTicketsDeal deal was found by Cheapflights users on 6/10. 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 CheapTicketsDeal is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/124:45 pmONT - LHR
2 stops30h 00mMultiple Airlines
Sat 8/210:55 amLHR - ONT
1 stop29h 52mMultiple Airlines
Deal found 6/10$830

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 June 12, 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

Tue 7/15

1:15 pm-9:50 am

1 stop12h 35m

London Heathrow

Wed 7/30

5:25 pm-10:25 am

1 stop25h 00m

$609

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 10/5

2:30 pm-2:25 pm

1 stop15h 55m

London Heathrow

Tue 10/14

6:10 am-12:02 am

2 stops25h 52m

$657

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 8/12

2:57 pm-2:25 pm

1 stop15h 28m

London Heathrow

Tue 9/2

11:30 am-10:48 pm

2 stops19h 18m

$659

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 8/12

5:05 am-6:30 am

2 stops17h 25m

London Heathrow

Tue 9/2

5:40 pm-12:32 pm

2 stops26h 52m

$664

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 8/8

6:39 pm-6:30 am

2 stops51h 51m

London Heathrow

Fri 8/22

12:05 pm-12:13 pm

2 stops32h 08m

$669

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 8/3

4:45 pm-12:50 pm

1 stop12h 05m

London Heathrow

Tue 8/19

11:15 am-5:52 pm

1 stop14h 37m

$672

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 8/4

2:14 pm-4:15 pm

2 stops18h 01m

London Heathrow

Tue 8/12

11:20 am-11:40 pm

2 stops20h 20m

$694

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 11/16

12:00 pm-10:35 am

1 stop14h 35m

London Heathrow

Fri 11/28

2:20 pm-10:41 pm

1 stop16h 21m

$696

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 9/8

10:56 pm-8:45 pm

1 stop13h 49m

London Heathrow

Wed 9/17

8:15 am-9:29 pm

1 stop21h 14m

$751

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 7/12

4:45 pm-6:45 am

2 stops30h 00m

London Heathrow

Sat 8/2

10:55 am-8:47 am

1 stop29h 52m

$830

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/11

Showing 1-10 of 21 results
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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 June 9, 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 52 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, November is the cheapest month in which you can book a flight from Ontario to London Heathrow Airport (average of $661). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of $1,108). 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 June 12, 2025.

It’s typically best to fly out from Ontario to London Heathrow Airport in the morning. Doing so could potentially save you 32% 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. Thursday afternoons flights should be avoided if possible as fares are typically the most expensive at this time.

Rainfall in Heathrow by month

Plan your trip to Heathrow by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in London Heathrow Airport ranges from 1.6 - 2.8 inches per month. January is typically the wettest month, when rainfall can reach 2.8 in. July is typically the driest time to visit London Heathrow Airport when rainfall is around 1.6 in.

Temperature in Heathrow by month

Plan your trip to Heathrow by taking into account the average temperature totals by month.

If weather is an important factor for your trip to London Heathrow Airport, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 62.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 39.2 F).

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 June 12, 2025.
See what other customers who have flown with Delta, KLM and United Airlines from Ontario to London have to say. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
8.0
Very good
7,946 reviews

Crew

8.5

Overall

8.0

Boarding

8.2

Comfort

7.9

Food

7.3

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
8.0
Very good
7,946 reviews
Delta
8.0
Very good
7,946 reviews

Crew

8.5

Overall

8.0

Boarding

8.2

Comfort

7.9

Food

7.3

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
7.8
Good
1,358 reviews
Delta
8.0
Very good
7,946 reviews

Crew

8.5

Overall

8.0

Boarding

8.2

Comfort

7.9

Food

7.3

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
8,790 reviews
Delta
8.0
Very good
7,946 reviews

Crew

8.5

Overall

8.0

Boarding

8.2

Comfort

7.9

Food

7.3

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.
Virgin Atlantic
7.4
Good
652 reviews
Delta
8.0
Very good
7,946 reviews

Crew

8.5

Overall

8.0

Boarding

8.2

Comfort

7.9

Food

7.3

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.
JetBlue
7.3
Good
2,925 reviews
Delta
8.0
Very good
7,946 reviews

Crew

8.5

Overall

8.0

Boarding

8.2

Comfort

7.9

Food

7.3

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 7 different airlines.

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

    According to our current data, Delta ($609), Virgin Atlantic ($614), and Iberia ($657) offers the cheapest pricing from Ontario to London Heathrow Airport. Delta is 27% cheaper than the average price of flights available within the next 90 days to this destination.

  • What are the cheapest airlines to fly from Ontario to London Heathrow Airport one-way?

    To fly one-way, consider booking your trip with JetBlue, which is currently one of the cheapest options available, starting at $394. KLM flights start at $399 while deals on Air Canada start at $410 one-way.

  • 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, November is the cheapest month in which you can book a flight from Ontario to London Heathrow Airport (average of $661). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of $1,108). 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 Ontario?

Book flights to Ontario if you plan to visit one of these locations
Hayes
Hounslow
Thornton Heath
Luton
Canterbury
Harrow
Dover
Stratford-upon-Avon
Gatwick
Orpington
Watford
Northampton
Croydon
Folkestone
Borehamwood
Broadway
Sutton
Aylesbury
Chelmsford
Brentwood

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Top 7 airlines flying from Ontario to Heathrow

Discover the top 7 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 June 12, 2025.
AirlineCheapestAverageFlexibilityOn-time
Virgin AtlanticCheapest$454Average$765FlexibilityNo cancel feeOn-time72%
IberiaCheapest$582Average$670FlexibilityNo cancel feeOn-time77%
DeltaCheapest$594Average$791FlexibilityNo cancel feeOn-timeN/A
KLMCheapest$608Average$763FlexibilityNo cancel feeOn-time75%
United AirlinesCheapest$633Average$796FlexibilityNo cancel feeOn-time69%
British AirwaysCheapest$647Average$820FlexibilityNo cancel feeOn-time70%
American AirlinesCheapest$648Average$894FlexibilityNo cancel feeOn-time71%

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