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Heathrow

$316+ 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 9/9. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LHR
Jul 8 — Jul 151
Tue 7/8
Tue 7/15
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 72 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 July 3, 2025.

Round-trip from

$526
(Delta)

One-way from

$316
(Kiwi.com)

Popular in

June

Cheapest in

March

Average price

$1,027
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 ($262 potential increase over avg. RT price).
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Cheapest flight prices on average. 5% potential price decrease ($43 potential savings vs. average RT price).
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Average for round-trip flights in July 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 July 3, 2025.

This Air France deal was found by Cheapflights users on 7/1. 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 France is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/241:15 pmONT - LHR
1 stop12h 35mMultiple Airlines
Thu 10/1610:55 amLHR - ONT
1 stop13h 19mMultiple Airlines
Deal found 7/1$526
This Delta deal was found by Cheapflights users on 7/2. 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.
Wed 8/2011:45 amONT - LHR
1 stop17h 45mDelta
Wed 8/2711:45 amLHR - ONT
2 stops18h 55mDelta
Deal found 7/2$527
This KLM deal was found by Cheapflights users on 7/3. 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.
Mon 9/159:50 amONT - LHR
1 stop16h 00mKLM
Fri 9/269:20 amLHR - ONT
1 stop17h 55mKLM
Deal found 7/3$574
This Iberia deal was found by Cheapflights users on 7/2. 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 9/22:57 pmONT - LHR
1 stop13h 48mIberia
Wed 9/176:30 amLHR - ONT
2 stops24h 03mIberia
Deal found 7/2$639
This Air Canada deal was found by Cheapflights users on 7/2. 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.
Wed 8/205:10 amONT - LHR
2 stops17h 20mAir Canada
Tue 8/262:05 pmLHR - ONT
2 stops35h 24mAir Canada
Deal found 7/2$640
This American Airlines deal was found by Cheapflights users on 7/1. 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 8/1912:00 pmLHR - ONT
1 stop14h 24mAmerican Airlines
Deal found 7/1$656
This United Airlines deal was found by Cheapflights users on 7/2. 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 8/31:34 pmONT - LHR
1 stop12h 06mUnited Airlines
Tue 8/192:50 pmLHR - ONT
1 stop13h 53mUnited Airlines
Deal found 7/2$658
This British Airways deal was found by Cheapflights users on 7/2. 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.
Wed 8/2012:46 pmONT - LHR
1 stop14h 04mBritish Airways
Fri 9/512:00 pmLHR - ONT
1 stop14h 54mBritish Airways
Deal found 7/2$661

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 July 3, 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

Wed 9/24

1:15 pm-9:50 am

1 stop12h 35m

London Heathrow

Thu 10/16

10:55 am-4:14 pm

1 stop13h 19m

$526

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 8/20

11:45 am-1:30 pm

1 stop17h 45m

London Heathrow

Wed 8/27

11:45 am-10:40 pm

2 stops18h 55m

$527

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 11/18

12:00 pm-10:35 am

1 stop14h 35m

London Heathrow

Wed 11/26

2:20 pm-10:41 pm

1 stop16h 21m

$534

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 9/2

2:57 pm-12:45 pm

1 stop13h 48m

London Heathrow

Wed 9/17

6:30 am-10:33 pm

2 stops24h 03m

$639

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 8/20

5:10 am-6:30 am

2 stops17h 20m

London Heathrow

Tue 8/26

2:05 pm-5:29 pm

2 stops35h 24m

$640

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 8/3

4:45 pm-12:50 pm

1 stop12h 05m

London Heathrow

Tue 8/19

12:00 pm-6:24 pm

1 stop14h 24m

$656

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 8/3

1:34 pm-9:40 am

1 stop12h 06m

London Heathrow

Tue 8/19

2:50 pm-8:43 pm

1 stop13h 53m

$658

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 8/20

12:46 pm-10:50 am

1 stop14h 04m

London Heathrow

Fri 9/5

12:00 pm-6:54 pm

1 stop14h 54m

$661

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 9/9

7:10 am-8:20 pm

3 stops29h 10m

$316

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 10/8

11:29 am-11:20 am

1 stop15h 51m

$376

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/1

Showing 1-10 of 15 results
1
2

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 27, 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 72 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 $1,098). 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 July 3, 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.

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 July 3, 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
8.0
Very good
7,982 reviews

Overall

8.0

Comfort

7.9

Food

7.3

Crew

8.5

Boarding

8.2

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
7,982 reviews
Delta
8.0
Very good
7,982 reviews

Overall

8.0

Comfort

7.9

Food

7.3

Crew

8.5

Boarding

8.2

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
1,367 reviews
Delta
8.0
Very good
7,982 reviews

Overall

8.0

Comfort

7.9

Food

7.3

Crew

8.5

Boarding

8.2

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
8,861 reviews
Delta
8.0
Very good
7,982 reviews

Overall

8.0

Comfort

7.9

Food

7.3

Crew

8.5

Boarding

8.2

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
654 reviews
Delta
8.0
Very good
7,982 reviews

Overall

8.0

Comfort

7.9

Food

7.3

Crew

8.5

Boarding

8.2

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
2,916 reviews
Delta
8.0
Very good
7,982 reviews

Overall

8.0

Comfort

7.9

Food

7.3

Crew

8.5

Boarding

8.2

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 ($526), KLM ($535), and Virgin Atlantic ($550) offers the cheapest pricing from Ontario to London Heathrow Airport. Delta is 37% 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 Virgin Atlantic, which is currently one of the cheapest options available, starting at $374. JetBlue flights start at $380 while deals on Air Canada start at $384 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 $1,098). 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
Hounslow
Hayes
Thornton Heath
Canterbury
Harrow
Dover
Stratford-upon-Avon
Gatwick
Orpington
Watford
Northampton
Croydon
Folkestone
Borehamwood
Broadway
Aylesbury
Chelmsford
Brentwood
Chichester
Swindon

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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 July 3, 2025.
AirlineCheapestAverageFlexibilityOn-time
IberiaCheapest$582Average$670FlexibilityNo cancel feeOn-time77%
KLMCheapest$608Average$763FlexibilityNo cancel feeOn-time75%
DeltaCheapest$613Average$796FlexibilityNo cancel feeOn-timeN/A
Virgin AtlanticCheapest$629Average$889FlexibilityNo cancel feeOn-time72%
United AirlinesCheapest$633Average$785FlexibilityNo cancel feeOn-time69%
British AirwaysCheapest$648Average$862FlexibilityNo cancel feeOn-time70%
American AirlinesCheapest$648Average$907FlexibilityNo cancel feeOn-time71%

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