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Heathrow

$236+ 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 1/22. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LHR
Jan 7 — Jan 141
Wed 1/7
Wed 1/14
1 adult, Economy
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Find cheap flights from Ontario to Heathrow with Cheapflights

1. Tell us where you want to go

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Cheapflights Tip: The best prices from Ontario to London Heathrow are usually found in November or December, booked 62 days in advance, depart on a Wednesday or Sunday and return on a Tuesday

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 December 8, 2025.

This Delta deal was found by Cheapflights users on 12/6. 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.
Wed 12/311:15 pmONT - LHR
1 stop12h 45mDelta
Sat 1/1010:45 amLHR - ONT
1 stop19h 03mDelta
Deal found 12/6$727
This oojo deal was found by Cheapflights users on 12/6. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/304:47 pmONT - LHR
1 stop12h 28mBritish Airways
Wed 5/612:55 pmLHR - ONT
1 stop17h 01mBritish Airways
Deal found 12/6$730
This Delta deal was found by Cheapflights users on 12/6. 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.
Wed 12/311:15 pmONT - LHR
1 stop12h 45mDelta
Fri 1/910:10 amLHR - ONT
2 stops18h 55mDelta
Deal found 12/6$732
This United Airlines deal was found by Cheapflights users on 12/7. 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.
Sat 12/276:39 pmONT - LHR
1 stop28h 46mUnited Airlines
Fri 1/98:00 amLHR - ONT
2 stops22h 53mUnited Airlines
Deal found 12/7$742
This United Airlines deal was found by Cheapflights users on 12/7. 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.
Sat 12/276:39 pmONT - LHR
1 stop28h 46mUnited Airlines
Sun 1/1112:05 pmLHR - ONT
1 stop17h 53mUnited Airlines
Deal found 12/7$788
This United Airlines deal was found by Cheapflights users on 12/7. 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.
Sat 12/276:39 pmONT - LHR
1 stop28h 46mUnited Airlines
Sat 1/108:00 amLHR - ONT
2 stops20h 58mUnited Airlines
Deal found 12/7$792
This United Airlines deal was found by Cheapflights users on 12/7. 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.
Sat 12/276:39 pmONT - LHR
1 stop28h 46mUnited Airlines
Thu 1/810:00 amLHR - ONT
1 stop19h 58mUnited Airlines
Deal found 12/7$793
This United Airlines deal was found by Cheapflights users on 12/7. 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 12/266:00 amONT - LHR
1 stop22h 00mUnited Airlines
Fri 1/93:10 pmLHR - ONT
3 stops29h 07mUnited Airlines
Deal found 12/7$797

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 December 8, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$628
(United Airlines)

One-way from

$236
(Kiwi.com)

Popular in

June

Cheapest in

November

Average price

$687
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. 24% potential increase in price ($267 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 December 2025
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 December 8, 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

Fri 1/23

1:24 pm-9:40 am

1 stop12h 16m

London Heathrow

Thu 1/29

6:35 am-5:43 pm

2 stops19h 08m

$628

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 1/5

6:39 pm-7:25 am

1 stop28h 46m

London Heathrow

Tue 1/20

8:30 am-9:59 pm

2 stops21h 29m

$630

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 1/30

6:39 pm-8:35 pm

2 stops17h 56m

London Heathrow

Tue 2/3

8:30 am-9:59 pm

2 stops21h 29m

$638

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 1/9

6:00 am-7:05 am

2 stops17h 05m

London Heathrow

Sun 1/18

6:20 am-9:48 pm

2 stops23h 28m

$639

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 1/9

5:05 am-6:40 am

2 stops17h 35m

London Heathrow

Sun 1/18

10:00 am-9:58 pm

1 stop19h 58m

$647

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 1/25

7:30 am-10:30 am

1 stop19h 00m

London Heathrow

Mon 2/2

2:30 pm-10:44 pm

1 stop16h 14m

$656

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 2/2

7:30 am-10:30 am

1 stop19h 00m

London Heathrow

Tue 2/10

10:45 am-4:15 pm

1 stop13h 30m

$656

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Thu 1/22

3:22 pm-12:50 pm

2 stops37h 28m

$323

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 1/30

6:39 pm-9:20 pm

2 stops18h 41m

$399

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 1/10

6:00 am-7:25 am

1 stop17h 25m

$399

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/7

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 December.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy2 starsTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*1 star
eDreamsPrice Accuracy3 starsTrust Score*3 stars
Thrive TravelPrice Accuracy3 starsTrust Score*1 star
AranGrantPrice Accuracy2 starsTrust Score*3 stars
CheapflightsfaresPrice Accuracy3 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 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 December 5, 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, 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 $698). 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 December 8, 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 December 8, 2025.
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
8,010 reviews

Entertainment

7.9

Boarding

8.1

Overall

7.9

Comfort

7.9

Crew

8.5

Food

7.3

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
8,010 reviews
Delta
7.9
Good
8,010 reviews

Entertainment

7.9

Boarding

8.1

Overall

7.9

Comfort

7.9

Crew

8.5

Food

7.3

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
9,078 reviews
Delta
7.9
Good
8,010 reviews

Entertainment

7.9

Boarding

8.1

Overall

7.9

Comfort

7.9

Crew

8.5

Food

7.3

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
11,044 reviews
Delta
7.9
Good
8,010 reviews

Entertainment

7.9

Boarding

8.1

Overall

7.9

Comfort

7.9

Crew

8.5

Food

7.3

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
3,042 reviews
Delta
7.9
Good
8,010 reviews

Entertainment

7.9

Boarding

8.1

Overall

7.9

Comfort

7.9

Crew

8.5

Food

7.3

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
7,564 reviews
Delta
7.9
Good
8,010 reviews

Entertainment

7.9

Boarding

8.1

Overall

7.9

Comfort

7.9

Crew

8.5

Food

7.3

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.

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

    United Airlines can get you from Ontario to London Heathrow Airport in just under 12h 16m. 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, Virgin Atlantic ($469), Delta ($570), and KLM ($580) offers the cheapest pricing from Ontario to London Heathrow Airport. Virgin Atlantic is 43% 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 $698). 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
Eastleigh
Dartford
Dover
Winchester
Croydon
Orpington
Northampton
Watford
Hayes
Borehamwood
Broadway
Aylesbury
Chipping Norton
Horley
Kingston upon Thames
Wembley

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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 December 8, 2025.
AirlineCheapestAverageFlexibilityOn-time
Virgin AtlanticCheapest$469Average$765FlexibilityNo cancel feeOn-time72%
DeltaCheapest$570Average$672FlexibilityNo cancel feeOn-timeN/A
KLMCheapest$580Average$672FlexibilityNo cancel feeOn-time75%
IberiaCheapest$615Average$728FlexibilityNo cancel feeOn-time77%
American AirlinesCheapest$624Average$795FlexibilityNo cancel feeOn-time71%
British AirwaysCheapest$653Average$862FlexibilityNo cancel feeOn-time70%
United AirlinesCheapest$665Average$817FlexibilityNo cancel feeOn-time69%

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