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Cheap flights from Ontario to London Heathrow Airport from £241

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 6/10. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LHR
1 Aug — 8 Aug1
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 2 July 2026.

Sun 15/1112:46
ONT
-
LHR
1 stop13h 14m
British Airways
Wed 16/1214:45
LHR
-
ONT
1 stop15h 34m
British Airways
Deal found 1/7£614
Tue 6/1011:13
ONT
-
LHR
1 stop19h 52m
Multiple Airlines
Mon 12/1016:10
LHR
-
ONT
1 stop13h 44m
Multiple Airlines
Deal found 28/6£618
Sun 18/1010:25
ONT
-
LHR
1 stop14h 35m
Multiple Airlines
Thu 29/1008:20
LHR
-
ONT
1 stop19h 51m
Multiple Airlines
Deal found 1/7£619
Wed 2/1205:00
ONT
-
LHR
2 stops18h 10m
Multiple Airlines
Wed 9/1209:55
LHR
-
ONT
1 stop19h 12m
Multiple Airlines
Deal found 30/6£621
Tue 8/1206:00
ONT
-
LHR
1 stop18h 15m
British Airways
Wed 9/1215:00
LHR
-
ONT
2 stops26h 54m
British Airways
Deal found 28/6£624
Tue 13/1008:03
ONT
-
LHR
2 stops21h 17m
Multiple Airlines
Thu 22/1009:15
LHR
-
ONT
2 stops22h 37m
Multiple Airlines
Deal found 29/6£624
Wed 29/723:51
ONT
-
LHR
1 stop25h 39m
Multiple Airlines
Wed 2/909:15
LHR
-
ONT
2 stops21h 44m
Multiple Airlines
Deal found 2/7£626
Tue 8/1206:00
ONT
-
LHR
2 stops17h 10m
Multiple Airlines
Thu 24/1214:45
LHR
-
ONT
1 stop15h 54m
Multiple Airlines
Deal found 30/6£630
Wed 18/1112:00
ONT
-
LHR
1 stop16h 20m
Multiple Airlines
Mon 30/1114:45
LHR
-
ONT
1 stop15h 38m
Multiple Airlines
Deal found 28/6£631

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 2 July 2026.

Round-trip from

£614

One-way from

£241

Popular in

June

Cheapest in

November

Average price

£1,023
British Airways
  • British Airways
  • 15/11-16/12
  • 2 total stops
  • 28h 48m total
  • Ontario to London
Search Deals
British Airways
  • British Airways
  • 6/10
  • 1 total stop
  • 13h 25m total
  • Ontario to London
Search Deals
Highest demand for flights based on searches. 31% potential increase in price (£252 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 6% potential price decrease (£33 potential savings vs. average return price).
Search Deals
Average for round-trip flights in July 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 2 July 2026.
Use the filters below to find and compare flights from Ontario to London Heathrow Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest return flight

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 26/10

14:13-12:20

1 stop15h 07m

London Heathrow

Mon 9/11

14:45-22:54

1 stop16h 09m

£697

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 23/8

08:50-07:25

1 stop14h 35m

London Heathrow

Tue 8/9

17:40-22:59

3 stops37h 19m

£716

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 22/8

13:18-21:20

2 stops24h 02m

London Heathrow

Tue 8/9

17:40-22:59

3 stops37h 19m

£720
Fastest return journey

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 3/8

13:06-10:00

1 stop12h 54m

London Heathrow

Wed 19/8

10:55-16:24

1 stop13h 29m

£723

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 3/8

18:01-15:35

1 stop13h 34m

London Heathrow

Thu 20/8

09:20-21:52

1 stop20h 32m

£729

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 15/9

15:14-15:05

1 stop15h 51m

London Heathrow

Fri 2/10

17:00-23:24

1 stop14h 24m

£729

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 16/8

13:18-09:40

1 stop12h 22m

London Heathrow

Sun 30/8

14:50-20:53

1 stop14h 03m

£760

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 12/9

21:10-20:45

1 stop15h 35m

London Heathrow

Wed 23/9

08:15-20:13

1 stop19h 58m

£785

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 2/8

13:50-11:10

1 stop13h 20m

London Heathrow

Tue 11/8

10:35-18:11

1 stop15h 36m

£802

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 19/9

09:25-11:55

2 stops18h 30m

London Heathrow

Thu 24/9

13:05-22:10

2 stops17h 05m

£846

Flights are sorted by cheapest return flights first.

Deals found on 28/6

Showing 1-10 of 24 resultsSorted by cheapest first
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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, November is the cheapest month in which you can book a flight from Ontario to London Heathrow Airport (average of £471). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of £1,201). 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?

    Alaska Airlines, United Airlines, and KLM can get you from Ontario to London Heathrow Airport in just under 12h 54m. Your travel time can differ by up to 2h 13m. 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, November is the cheapest month in which you can book a flight from Ontario to London Heathrow Airport (average of £471). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of £1,201). 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
Hounslow
Milton Keynes
Luton
Wembley
Gatwick
Croydon
Slough
Ilford
Hayes
Brentford
Colchester
Northampton
Watford
Kingston upon Thames
Swindon
Eastbourne
Poole
Southall
Aylesbury
Romford

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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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