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Cheap flights from Ontario to London Heathrow Airport from £269

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 14/4. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LHR
20 Mar — 27 Mar1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from Ontario to Heathrow

Enter your travel dates to find the best prices.

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 18 February 2026.

Tue 17/223:58
ONT
-
LHR
1 stop22h 52m
British Airways
Tue 24/216:30
LHR
-
ONT
1 stop25h 36m
British Airways
Deal found 16/2£450
Wed 18/214:39
ONT
-
LHR
1 stop13h 01m
British Airways
Fri 27/216:30
LHR
-
ONT
1 stop15h 29m
British Airways
Deal found 17/2£452
Wed 18/207:00
ONT
-
LHR
1 stop15h 50m
Iberia
Wed 25/216:30
LHR
-
ONT
1 stop29h 19m
Iberia
Deal found 17/2£465
Tue 14/414:08
ONT
-
LHR
1 stop16h 17m
Iberia
Tue 28/406:10
LHR
-
ONT
2 stops22h 44m
Iberia
Deal found 16/2£477
Wed 15/412:49
ONT
-
LHR
1 stop16h 26m
Delta
Tue 5/509:55
LHR
-
ONT
2 stops19h 05m
Delta
Deal found 16/2£478
Thu 19/214:39
ONT
-
LHR
1 stop13h 01m
British Airways
Thu 26/216:30
LHR
-
ONT
1 stop15h 29m
British Airways
Deal found 14/2£479
Wed 18/214:39
ONT
-
LHR
1 stop13h 01m
British Airways
Sun 22/216:30
LHR
-
ONT
1 stop15h 29m
British Airways
Deal found 16/2£480
Sat 14/213:15
ONT
-
LHR
1 stop14h 25m
Delta
Fri 27/212:30
LHR
-
ONT
1 stop16h 35m
Delta
Deal found 13/2£480
Sat 18/418:49
ONT
-
LHR
1 stop28h 36m
United Airlines
Thu 30/414:05
LHR
-
ONT
2 stops38h 31m
United Airlines
Deal found 16/2£485
Thu 19/210:56
ONT
-
LHR
1 stop13h 19m
Iberia
Thu 26/216:30
LHR
-
ONT
1 stop15h 29m
Iberia
Deal found 14/2£486

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 18 February 2026.

Round-trip from

£477

One-way from

£269

Popular in

June

Cheapest in

November

Average price

£538
Iberia
  • Iberia
  • 14/4-28/4
  • 3 total stops
  • 39h 01m total
  • Ontario to London
Search Deals
14/4
  • 14/4
  • 3 total stops
  • 31h 20m total
  • Ontario to London
Search Deals
Highest demand for flights based on searches. 23% potential increase in price (£141 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 5% potential price decrease (£26 potential savings vs. average return price).
Search Deals
Average for round-trip flights in February 2026
Search Deals

Cheapflights Fare Finder

 
Customise 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 858,174 searches. Data last updated 18 February 2026.
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 15/4

11:53-15:35

1 stop19h 42m

London Heathrow

Tue 5/5

06:30-17:15

2 stops18h 45m

£478

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 18/3

13:40-12:00

1 stop15h 20m

London Heathrow

Mon 23/3

10:05-17:41

1 stop14h 36m

£488

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 4/3

13:10-10:00

1 stop12h 50m

London Heathrow

Wed 11/3

06:30-17:12

2 stops17h 42m

£488

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 23/3

06:00-10:30

1 stop21h 30m

London Heathrow

Thu 2/4

06:30-23:51

2 stops25h 21m

£489

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 18/3

06:00-08:45

2 stops19h 45m

London Heathrow

Wed 25/3

10:45-23:51

1 stop20h 06m

£491

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 16/3

13:50-09:40

1 stop12h 50m

London Heathrow

Tue 31/3

14:50-20:36

1 stop13h 46m

£492

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 18/3

13:40-12:00

1 stop15h 20m

London Heathrow

Thu 9/4

09:30-09:56

2 stops32h 26m

£502

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 2/3

13:50-12:00

1 stop14h 10m

London Heathrow

Wed 18/3

13:35-22:18

1 stop15h 43m

£508

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 23/3

13:40-12:00

1 stop15h 20m

London Heathrow

Thu 2/4

13:00-22:45

1 stop17h 45m

£510

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 23/3

13:20-10:00

1 stop13h 40m

London Heathrow

Thu 9/4

13:25-21:00

1 stop15h 35m

£510

Flights are sorted by cheapest return flights first.

Deals found on 15/2

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 return 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

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 £345). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of £516). 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.

How much does it cost for a return flight from Ontario to London Heathrow Airport?

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?

    Most people fly from Ontario (ONT) if they book a flight from Ontario to London Heathrow. On average, Ontario has 0 outbound flights to London Heathrow per day from 0 airlines. Ontario is conveniently located just 3.1 mi from Ontario’s city center.

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

    Delta and United Airlines can get you from Ontario to London Heathrow Airport in just under 15h 20m. Your travel time can differ by up to 4h 22m. The distance between Ontario and London Heathrow Airport is about 5407 mi. This flight may include one or multiple stops.

  • 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 holiday 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 £345). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of £516). 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

Travelling to a place near London Heathrow Airport?

Book flights to London Heathrow Airport if you plan to visit one of these locations
Milton Keynes
Croydon
Luton
Wembley
Northampton
Gatwick
Slough
Hounslow
Ilford
Hayes
Brentford
Colchester
Watford
Guildford
Chelmsford
Eastbourne
Crawley
Kingston upon Thames
Ipswich
Swindon

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How does Cheapflights help users find flights from Ontario to Heathrow?

When you search for this flight from Ontario to Heathrow, Cheapflights searches on 900+ travel sites to save you time finding great flight deals online. Additionally, we offer filter features so you can choose a preferred cabin class or airline, see different price ranges, and much more so you can book the flight for you.

Why should you use Cheapflights to find cheap flight tickets from Ontario to Heathrow?

It’s simple! Cheapflights, which is free to use for everyone, saves millions of users time and money every year by helping them find the cheapest and most suitable flights from Ontario to Heathrow.

Can Cheapflights find flights from Ontario to Heathrow with no change fees?

Certainly. Search results for flights to Heathrow from Ontario shown to you on Cheapflights can be narrowed down with different useful search filters, which includes flexible booking options.

Can Cheapflights notify me if prices for flights from Ontario to Heathrow become cheaper?

Yes, and it’s super simple to set up. Click the bell icon next to the flight deals above and provide a valid email address to enable Price Alerts. That’s it!

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