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Cheap flights from Ontario to London Heathrow Airport from £305

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 10/7. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LHR
12 Jun — 19 Jun1
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 13 May 2026.

Mon 19/1013:31
ONT
-
LHR
1 stop12h 59m
British Airways
Fri 30/1014:25
LHR
-
ONT
1 stop14h 10m
British Airways
Deal found 12/5£659
Tue 3/1110:47
ONT
-
LHR
1 stop13h 28m
Iberia
Tue 10/1106:00
LHR
-
ONT
2 stops24h 23m
Iberia
Deal found 11/5£661
Mon 17/807:05
ONT
-
LHR
1 stop16h 10m
Virgin Atlantic
Wed 2/911:45
LHR
-
ONT
2 stops19h 59m
Virgin Atlantic
Deal found 11/5£662
Mon 3/809:43
ONT
-
LHR
2 stops19h 22m
Delta
Thu 20/806:30
LHR
-
ONT
2 stops23h 22m
Delta
Deal found 8/5£665
Wed 16/914:22
ONT
-
LHR
1 stop16h 03m
Iberia
Mon 5/1019:25
LHR
-
ONT
2 stops33h 43m
Iberia
Deal found 8/5£669
Tue 3/1116:47
ONT
-
LHR
1 stop12h 28m
British Airways
Thu 12/1115:00
LHR
-
ONT
1 stop15h 23m
British Airways
Deal found 10/5£673
Sat 22/811:00
ONT
-
LHR
2 stops26h 20m
United Airlines
Tue 8/909:30
LHR
-
ONT
2 stops20h 29m
United Airlines
Deal found 12/5£674

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 13 May 2026.

Round-trip from

£659

One-way from

£305

Popular in

June

Cheapest in

November

Average price

£765
British Airways
  • British Airways
  • 19/10-30/10
  • 2 total stops
  • 27h 09m total
  • Ontario to London
Search Deals
JetBlue
  • JetBlue
  • 10/7
  • 1 total stop
  • 25h 40m total
  • Ontario to London
Search Deals
Highest demand for flights based on searches. 30% potential increase in price (£211 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 7% potential price decrease (£35 potential savings vs. average return price).
Search Deals
Average for round-trip flights in May 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 13 May 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 17/8

12:55-15:35

2 stops18h 40m

London Heathrow

Wed 2/9

09:55-23:44

2 stops21h 49m

£666

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 3/8

11:56-13:15

1 stop17h 19m

London Heathrow

Thu 20/8

09:20-18:29

1 stop17h 09m

£684

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 14/9

15:12-15:05

1 stop15h 53m

London Heathrow

Tue 22/9

17:00-23:24

1 stop14h 24m

£757
Fastest return journey

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Thu 9/7

13:18-09:40

1 stop12h 22m

London Heathrow

Thu 16/7

14:50-20:42

1 stop13h 52m

£883

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 4/9

13:18-12:25

1 stop15h 07m

London Heathrow

Sun 13/9

14:50-20:52

1 stop14h 02m

£884

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 3/7

18:39-21:25

2 stops18h 46m

London Heathrow

Thu 9/7

18:00-21:55

2 stops35h 55m

£887

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 2/10

21:10-20:45

1 stop15h 35m

London Heathrow

Sun 11/10

08:15-22:09

1 stop21h 54m

£915

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 17/7

13:18-12:25

1 stop15h 07m

London Heathrow

Sat 25/7

11:25-20:42

1 stop17h 17m

£935

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 24/7

13:18-12:25

1 stop15h 07m

London Heathrow

Mon 3/8

14:50-20:42

1 stop13h 52m

£935

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 24/5

12:04-15:05

1 stop19h 01m

London Heathrow

Sun 31/5

17:00-23:58

1 stop14h 58m

£952

Flights are sorted by cheapest return flights first.

Deals found on 12/5

Showing 1-10 of 23 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 £461). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of £1,175). 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?

    Virgin Atlantic, KLM, and Alaska Airlines can get you from Ontario to London Heathrow Airport in just under 15h 53m. Your travel time can differ by up to 2h 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, November is the cheapest month in which you can book a flight from Ontario to London Heathrow Airport (average of £461). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of £1,175). 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
Hounslow
Croydon
Wembley
Northampton
Luton
Gatwick
Slough
Ilford
Hayes
Brentford
Colchester
Romford
Watford
Kingston upon Thames
Eastbourne
Swindon
Ipswich
Southend-on-Sea
Guildford

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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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