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Cheap flights from Ontario to London Heathrow Airport from £228

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 17/1. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LHR
4 Jan — 11 Jan1
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 5 December 2025.

Wed 10/1213:29ONT - LHR
1 stop12h 31mDelta
Wed 24/1210:45LHR - ONT
1 stop19h 48mDelta
Deal found 3/12£448
Wed 10/1213:34ONT - LHR
1 stop12h 06mUnited Airlines
Fri 9/110:00LHR - ONT
1 stop19h 58mUnited Airlines
Deal found 3/12£485
Thu 11/1210:47ONT - LHR
1 stop15h 13mBritish Airways
Mon 15/1219:05LHR - ONT
2 stops26h 50mBritish Airways
Deal found 3/12£492
Thu 11/1213:34ONT - LHR
1 stop12h 06mUnited Airlines
Thu 18/1210:05LHR - ONT
1 stop15h 38mUnited Airlines
Deal found 3/12£505
Thu 11/1206:40ONT - LHR
1 stop22h 10mDelta
Mon 15/1214:45LHR - ONT
1 stop16h 02mDelta
Deal found 4/12£523
Thu 11/1213:50ONT - LHR
1 stop14h 10mUnited Airlines
Mon 15/1210:05LHR - ONT
1 stop15h 32mUnited Airlines
Deal found 2/12£524
Tue 16/1206:00ONT - LHR
1 stop17h 30mUnited Airlines
Wed 24/1212:05LHR - ONT
1 stop17h 47mUnited Airlines
Deal found 3/12£527
Tue 16/1206:00ONT - LHR
1 stop17h 30mUnited Airlines
Fri 9/115:10LHR - ONT
2 stops29h 07mUnited Airlines
Deal found 3/12£529
Wed 10/1213:50ONT - LHR
1 stop14h 10mUnited Airlines
Sun 14/1210:05LHR - ONT
1 stop15h 32mUnited Airlines
Deal found 3/12£579
Sat 13/1213:34ONT - LHR
1 stop12h 06mUnited Airlines
Mon 22/1213:45LHR - ONT
1 stop16h 56mUnited Airlines
Deal found 3/12£591
Thu 11/1213:50ONT - LHR
1 stop14h 10mUnited Airlines
Sun 14/1210:05LHR - ONT
1 stop15h 32mUnited Airlines
Deal found 3/12£599

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 5 December 2025.

Round-trip from

£432

One-way from

£228

Popular in

June

Cheapest in

November

Average price

£557
Iberia
  • Iberia
  • 21/1-29/1
  • 3 total stops
  • 38h 20m total
  • Ontario to London
Search Deals
17/1
  • 17/1
  • 2 total stops
  • 55h 40m total
  • Ontario to London
Search Deals
Highest demand for flights based on searches. 23% potential increase in price (£145 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 5% potential price decrease (£25 potential savings vs. average return price).
Search Deals
Average for round-trip flights in December 2025
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 5 December 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 15/4

11:55-14:15

1 stop18h 20m

London Heathrow

Tue 5/5

06:15-17:16

2 stops19h 01m

£460

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 20/4

12:00-13:30

1 stop17h 30m

London Heathrow

Thu 7/5

06:15-17:16

2 stops19h 01m

£460

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 15/4

17:02-15:05

1 stop14h 03m

London Heathrow

Tue 5/5

16:25-23:40

1 stop15h 15m

£465

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 20/4

06:00-09:50

1 stop19h 50m

London Heathrow

Thu 7/5

11:20-22:40

1 stop19h 20m

£465

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 30/1

18:39-21:20

2 stops18h 41m

London Heathrow

Tue 3/2

06:30-21:59

2 stops23h 29m

£477

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 20/1

13:24-09:40

1 stop12h 16m

London Heathrow

Wed 4/2

11:30-22:53

2 stops19h 23m

£477

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 9/1

06:00-07:05

2 stops17h 05m

London Heathrow

Sun 18/1

06:20-21:48

2 stops23h 28m

£477

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 9/1

13:24-09:40

1 stop12h 16m

London Heathrow

Sun 18/1

11:35-20:58

1 stop17h 23m

£483

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 13/2

06:00-07:25

1 stop17h 25m

London Heathrow

Sat 21/2

12:05-21:59

1 stop17h 54m

£490

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 20/1

13:24-09:40

1 stop12h 16m

London Heathrow

Tue 3/2

10:05-17:55

1 stop15h 50m

£490

Flights are sorted by cheapest return flights first.

Deals found on 3/12

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

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 28 November 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 62 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, December is the cheapest month in which you can book a flight from Ontario to London Heathrow Airport (average of £352). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of £524). 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.

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, British Airways, and KLM can get you from Ontario to London Heathrow Airport in just under 14h 03m. Your travel time can differ by up to 5h 47m. 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 £352). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of £524). 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
Northampton
Hounslow
Slough
Gatwick
Luton
Ilford
Wembley
Colchester
Brentford
Watford
Hayes
Crawley
Deal
Winchester
Swindon
Romford
Bedford
Chichester

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for Ontario to Heathrow

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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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