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$503+ Cheap flights from Heathrow (LHR) to Ontario (ONT)

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 9/1. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — ONT
Jun 17 — Jun 241
Tue 6/17
Tue 6/24
1 adult, Economy
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Cheapflights Tip: The best prices from London Heathrow to Ontario are usually found in February or July, booked 27 days in advance, depart on a Tuesday or Wednesday and return on a Wednesday

Cheap flight deals from Heathrow to Ontario

Discover tips and strategies to find the most affordable flight options for your journey from Heathrow (LHR) to Ontario (ONT). 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

$503
(Netflights)

Popular in

August

Cheapest in

February

Average price

$711
From London Heathrow to Ontario
Search Deals
Highest demand for flights based on searches. 4% potential increase in price ($30 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease ($23 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 Heathrow to Ontario

Cheapest flights from Heathrow to Ontario
Explore the most affordable flight options available from Heathrow to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on June 12, 2025.

This Netflights 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 Netflights is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/14:25 pmLHR - ONT
1 stop15h 42mBritish Airways
Tue 9/304:45 pmONT - LHR
1 stop13h 55mBritish Airways
Deal found 6/11$503
This Netflights 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 Netflights is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/1711:45 amLHR - ONT
2 stops20h 01mVirgin Atlantic
Wed 9/2412:00 pmONT - LHR
1 stop17h 30mVirgin Atlantic
Deal found 6/10$505
This TravelUp 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 TravelUp is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/86:30 amLHR - ONT
2 stops18h 41mKLM
Mon 9/159:55 amONT - LHR
1 stop15h 55mKLM
Deal found 6/10$507
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.
Tue 9/212:00 pmLHR - ONT
1 stop14h 24mAmerican Airlines
Wed 9/101:10 pmONT - LHR
1 stop15h 40mAmerican Airlines
Deal found 6/11$526
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.
Mon 8/186:30 amLHR - ONT
2 stops34h 25mDelta
Thu 9/1111:29 amONT - LHR
1 stop18h 46mDelta
Deal found 6/12$531
This World Air Fares 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 World Air Fares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/810:30 amLHR - ONT
1 stop20h 04mFinnair
Tue 7/154:45 pmONT - LHR
1 stop13h 55mFinnair
Deal found 6/11$598
This Vliegwinkel 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 Vliegwinkel is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/2311:15 amLHR - ONT
1 stop14h 57mRoyal Air Maroc
Mon 7/78:15 amONT - LHR
1 stop16h 45mRoyal Air Maroc
Deal found 6/10$647
This United 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/2212:05 pmLHR - ONT
2 stops18h 25mUnited Airlines
Mon 9/291:15 pmONT - LHR
1 stop12h 25mUnited Airlines
Deal found 6/11$661
This Iberia 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 Iberia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 6/2612:00 pmLHR - ONT
1 stop15h 01mIberia
Wed 7/212:49 pmONT - LHR
1 stop14h 01mIberia
Deal found 6/10$664
This Air Canada 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 Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/2811:10 amLHR - ONT
2 stops18h 21mMultiple Airlines
Tue 11/47:00 amONT - LHR
2 stops15h 30mMultiple Airlines
Deal found 6/10$681

Cheapflights Fare Finder

Customize your flight search to find flights from Heathrow to Ontario 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 London Heathrow Airport to Ontario that are best for you.

Fly from

Heathrow

Fly to

Ontario

Route

Depart

Return

Price

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Mon 9/1

8:20 am-6:24 pm

1 stop18h 04m

Ontario

Tue 9/30

8:15 am-6:25 am

1 stop14h 10m

$503

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Wed 9/17

11:45 am-11:46 pm

2 stops20h 01m

Ontario

Wed 9/24

12:00 pm-1:30 pm

1 stop17h 30m

$505

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Mon 9/8

6:30 am-5:11 pm

2 stops18h 41m

Ontario

Mon 9/15

9:55 am-9:50 am

1 stop15h 55m

$507

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Tue 9/2

12:00 pm-6:24 pm

1 stop14h 24m

Ontario

Tue 9/9

4:45 pm-12:50 pm

1 stop12h 05m

$526

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Mon 8/18

6:30 am-8:55 am

2 stops34h 25m

Ontario

Thu 9/11

11:29 am-2:15 pm

1 stop18h 46m

$531

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Tue 7/8

10:30 am-10:34 pm

1 stop20h 04m

Ontario

Tue 7/15

4:45 pm-2:40 pm

1 stop13h 55m

$598

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Mon 6/23

11:15 am-6:12 pm

1 stop14h 57m

Ontario

Mon 7/7

8:15 am-9:00 am

1 stop16h 45m

$647

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Mon 9/22

12:05 pm-10:30 pm

2 stops18h 25m

Ontario

Mon 9/29

1:15 pm-9:40 am

1 stop12h 25m

$661

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Thu 6/26

12:00 pm-7:01 pm

1 stop15h 01m

Ontario

Wed 7/2

12:49 pm-10:50 am

1 stop14h 01m

$664

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Tue 10/28

11:10 am-10:31 pm

2 stops18h 21m

Ontario

Tue 11/4

7:00 am-6:30 am

2 stops15h 30m

$681

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/12

Showing 1-10 of 18 results
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Best time to book a flight from Heathrow to Ontario

Have a flexible travel schedule? Discover the best time to fly to Ontario from Heathrow 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 London Heathrow Airport to Ontario

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

Use this chart to determine the optimal time to book a round-trip flight from Heathrow to Ontario. Price data was last updated on June 9, 2025.

Booking 27 days in advance of your planned departure date is, on average, the best time to get cheap flights from London Heathrow Airport to Ontario. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

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

Currently, August is the cheapest month in which you can book a flight from London Heathrow Airport to Ontario (average of $246). Flying from London Heathrow Airport to Ontario in March is currently the most expensive (average of $328). 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 LHR to ONT?

Find hourly flight availability from Heathrow to Ontario. 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.

Unlike at noon, when flights are generally more expensive, you can save up to 23% on flights from London Heathrow Airport to Ontario by exploring options for tickets in the afternoon.

Rainfall in Ontario by month

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

In terms of precipitation, rainfall in Ontario ranges from 0.1 - 3.4 inches per month. February is typically the wettest month, when rainfall can reach 3.4 in. June is typically the driest time to visit Ontario when rainfall is around 0.1 in.

Temperature in Ontario by month

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

If weather is an important factor for your trip to Ontario, use this chart to help with planning. For those seeking warmer temperatures, August is the ideal time of year to visit, when temperatures reach an average of 78.8 F. Travelers looking to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 53.6 F).

Reviews of airlines servicing Ontario

Get insights into the airlines that provide service to Ontario. 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 Ontario. Reviews last updated June 12, 2025.
Read through reviews of airlines operating flights from London to Ontario, such as Delta, KLM and Finnair. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
8.0
Very good
7,950 reviews

Entertainment

7.9

Boarding

8.2

Comfort

7.9

Food

7.3

Overall

8.0

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception
Delta
8.0
Very good
7,950 reviews
Delta
8.0
Very good
7,950 reviews

Entertainment

7.9

Boarding

8.2

Comfort

7.9

Food

7.3

Overall

8.0

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception
KLM
7.8
Good
1,358 reviews
Delta
8.0
Very good
7,950 reviews

Entertainment

7.9

Boarding

8.2

Comfort

7.9

Food

7.3

Overall

8.0

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception
Finnair
7.6
Good
1,290 reviews
Delta
8.0
Very good
7,950 reviews

Entertainment

7.9

Boarding

8.2

Comfort

7.9

Food

7.3

Overall

8.0

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception
Air France
7.5
Good
1,463 reviews
Delta
8.0
Very good
7,950 reviews

Entertainment

7.9

Boarding

8.2

Comfort

7.9

Food

7.3

Overall

8.0

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception
United Airlines
7.4
Good
8,790 reviews
Delta
8.0
Very good
7,950 reviews

Entertainment

7.9

Boarding

8.2

Comfort

7.9

Food

7.3

Overall

8.0

Crew

8.5

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

Related info for your journey

Find useful and relevant information for your journey from Heathrow to Ontario. 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 into for flights to Ontario from London Heathrow?

    Ontario (ONT) is the airport you will fly into if you book a flight from London Heathrow to Ontario. You should not have trouble finding flights to Ontario from London Heathrow; the airport handles an average of 0 inbound flights from London Heathrow per day. You should also have plenty of airline options to choose from since 1 airline has flights to the Ontario airport from London Heathrow. It is only a 3.1 mi journey from Ontario (ONT) to Ontario’s city center.

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

    Flying on British Airways is currently your cheapest option to Ontario, with prices starting at $503. Additional round-trip tickets that might be worth considering are offered by Virgin Atlantic and KLM, with the lowest prices starting at $505 and $507, respectively. These flights start at 29% lower than the current average price 3 months from now.

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

    To fly one-way, consider booking your trip with British Airways, which is currently one of the cheapest options available, starting at $593. Iberia flights start at $629 while deals on JetBlue start at $792 one-way.

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

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

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

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

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

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

    Currently, August is the cheapest month in which you can book a flight from London Heathrow Airport to Ontario (average of $246). Flying from London Heathrow Airport to Ontario in March is currently the most expensive (average of $328). 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

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Alternative routes for Heathrow to Ontario

See prices for flight routes from nearby airports that may be better suited for you.
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Top airline flying from Heathrow to Ontario

Discover the top airline that operate flights from Heathrow to Ontario. 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
United AirlinesCheapest$560Average$694FlexibilityNo cancel feeOn-time69%

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