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Cheap flights from Ontario to London Heathrow Airport from £276

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 8/10. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LHR
31 Aug — 7 Sep1
1 adult

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 26 August 2025.

Round-trip from

£388

One-way from

£276

Popular in

June

Cheapest in

October

Average price

£639
Delta
  • Delta
  • 1/10-30/10
  • 3 total stops
  • 47h 36m total
  • Ontario to London
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8/10
  • 8/10
  • 3 total stops
  • 53h 35m total
  • Ontario to London
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Highest demand for flights based on searches. 22% potential increase in price (£135 potential increase over avg. return price).
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Cheapest flight prices on average. 5% potential price decrease (£24 potential savings vs. average return price).
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Average for round-trip flights in August 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 26 August 2025.

Wed 1/1006:00ONT - LHR
1 stop24h 15mDelta
Thu 30/1006:20LHR - ONT
2 stops23h 21mDelta
Deal found 25/8£388
Mon 1/911:45ONT - LHR
1 stop15h 25mDelta
Tue 16/909:20LHR - ONT
1 stop17h 55mDelta
Deal found 25/8£390
Mon 22/913:15ONT - LHR
1 stop12h 35mDelta
Tue 30/910:55LHR - ONT
1 stop20h 47mDelta
Deal found 24/8£393
Tue 23/907:05ONT - LHR
2 stops16h 10mDelta
Wed 1/1011:20LHR - ONT
1 stop19h 03mDelta
Deal found 24/8£397
Wed 24/911:55ONT - LHR
1 stop17h 35mKLM
Tue 30/917:25LHR - ONT
1 stop31h 35mKLM
Deal found 24/8£397
Mon 15/907:05ONT - LHR
1 stop16h 10mDelta
Fri 26/906:15LHR - ONT
2 stops18h 45mDelta
Deal found 26/8£417
Tue 9/1213:00ONT - LHR
1 stop13h 00mDelta
Thu 8/106:30LHR - ONT
2 stops24h 08mDelta
Deal found 24/8£417
Mon 22/911:55ONT - LHR
1 stop15h 15mVirgin Atlantic
Sat 11/1006:15LHR - ONT
2 stops23h 05mVirgin Atlantic
Deal found 25/8£425
Fri 3/1011:55ONT - LHR
1 stop17h 35mDelta
Fri 17/1009:20LHR - ONT
1 stop21h 02mDelta
Deal found 24/8£427

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 26 August 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 8/10

11:48-11:20

1 stop15h 32m

London Heathrow

Wed 15/10

06:15-17:10

2 stops18h 55m

£388

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 1/10

06:00-14:15

1 stop24h 15m

London Heathrow

Thu 30/10

06:20-17:10

2 stops17h 50m

£388

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 23/11

11:45-09:00

1 stop13h 15m

London Heathrow

Tue 9/12

10:45-16:14

1 stop13h 29m

£393

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 24/9

11:55-13:30

1 stop17h 35m

London Heathrow

Wed 1/10

09:20-22:23

1 stop21h 03m

£393

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 10/11

11:45-09:00

1 stop13h 15m

London Heathrow

Tue 13/1

10:45-16:19

1 stop13h 34m

£393

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 22/10

13:15-09:50

1 stop12h 35m

London Heathrow

Fri 31/10

10:45-19:19

1 stop15h 34m

£393

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 23/9

11:55-13:30

1 stop17h 35m

London Heathrow

Wed 1/10

09:20-19:15

1 stop17h 55m

£393

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 22/9

13:15-09:50

1 stop12h 35m

London Heathrow

Tue 30/9

10:55-23:42

1 stop20h 47m

£393

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 8/10

08:00-21:35

3 stops53h 35m

£276

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 1/10

22:56-20:45

1 stop13h 49m

£278

Flights are sorted by cheapest return flights first.

Deals found on 24/8

Showing 1-10 of 19 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 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

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 return flight from Ontario to Heathrow. Price data was last updated on 22 August 2025.

To ensure you get the cheapest price possible for a flight from Ontario to London Heathrow Airport, you should look to book at least 72 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

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

Currently, January is the cheapest month in which you can book a flight from Ontario to London Heathrow Airport (average of £112). Flying from Ontario to London Heathrow Airport in August is currently the most expensive (average of £164). 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 26 August 2025.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Ontario to London Heathrow Airport as you normally would.

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 can get you from Ontario to London Heathrow Airport in just under 15h 32m. 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 to fly from Ontario to London Heathrow Airport one-way?

    For one-way options, check prices for JetBlue. According to our data, you can fly for as low as £278. Users have also found prices from £287 and £288 on Virgin Atlantic and British Airways, respectively.

  • 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, January is the cheapest month in which you can book a flight from Ontario to London Heathrow Airport (average of £112). Flying from Ontario to London Heathrow Airport in August is currently the most expensive (average of £164). 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
Hounslow
Gatwick
Slough
Northampton
Luton
Deal
Wembley
Ilford
Crawley
Hayes
Watford
Folkestone
Ipswich
Chichester
Winchester
Eastbourne
Swindon
Dartford

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Fly with Cheapflights

Find the best flight deals on Cheapflights, where travellers can enjoy low prices and a wide availability of flights to their desired destinations.

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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