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Cheap flights from Ontario to London Heathrow Airport from £210

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 17/10. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LHR
4 Sep — 11 Sep1
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 August 2026.

Mon 9/1118:37 -
1 stop28h 48m
Thu 12/1106:50 -
2 stops19h 57m
Deal found 2/8£548
Sun 1/1113:29 -
2 stops34h 11m
Wed 4/1106:50 -
2 stops19h 57m
Deal found 3/8£559
Sun 11/1023:05 -
1 stop13h 40m
Sun 25/1014:45 -
1 stop15h 57m
Deal found 31/7£595
Sun 1/1105:00 -
2 stops20h 20m
Wed 25/1114:45 -
1 stop16h 19m
Deal found 2/8£597
Sun 15/1106:00 -
1 stop22h 20m
Sun 22/1114:45 -
1 stop16h 19m
Deal found 5/8£598
Sun 20/922:39 -
1 stop14h 06m
Sun 27/917:00 -
1 stop29h 16m
Deal found 31/7£599
Mon 9/1106:00 -
1 stop22h 20m
Sun 15/1114:45 -
1 stop16h 09m
Deal found 4/8£600
Tue 1/1214:22 -
1 stop13h 38m
Sun 13/1214:45 -
1 stop32h 02m
Deal found 4/8£604
Sat 7/1119:10 -
1 stop33h 10m
Thu 12/1114:45 -
1 stop16h 09m
Deal found 2/8£606
Sat 7/1116:09 -
1 stop36h 11m
Sun 15/1114:45 -
1 stop16h 09m
Deal found 4/8£608

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 August 2026.

Round-trip from

£548

One-way from

£210

Popular in

June

Cheapest in

November

Average price

£687
United Airlines
  • United Airlines
  • 9/11-12/11
  • 3 total stops
  • 48h 45m total
  • Ontario to London
Search Deals
17/10
  • 17/10
  • 3 total stops
  • 31h 00m total
  • Ontario to London
Search Deals
Highest demand for flights based on searches. 32% potential increase in price (£253 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 August 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 5 August 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

Wed 9/9

13:04-10:30

1 stop13h 26m

London Heathrow

Fri 11/12

14:45-22:19

1 stop15h 34m

£721

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 15/9

07:05-06:25

1 stop15h 20m

London Heathrow

Wed 23/9

10:55-16:35

1 stop13h 40m

£721
Fastest return journey

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 9/9

13:56-11:10

1 stop13h 14m

London Heathrow

Sun 13/9

14:50-20:53

1 stop14h 03m

£757

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 29/8

15:07-15:05

1 stop15h 58m

London Heathrow

Wed 30/9

17:00-11:16

1 stop26h 16m

£779

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 18/8

09:43-13:05

2 stops19h 22m

London Heathrow

Mon 24/8

20:55-16:24

2 stops27h 29m

£791

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 25/8

07:00-07:15

2 stops16h 15m

London Heathrow

Mon 7/9

11:05-22:59

2 stops43h 54m

£796

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 7/12

10:05-10:50

2 stops16h 45m

London Heathrow

Mon 14/12

12:15-22:39

2 stops18h 24m

£844

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 15/8

21:20-15:05

1 stop33h 45m

London Heathrow

Sun 23/8

17:00-23:24

1 stop14h 24m

£853

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 1/12

10:05-10:50

2 stops16h 45m

London Heathrow

Tue 8/12

12:15-22:39

2 stops18h 24m

£879

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 13/12

08:05-10:50

2 stops18h 45m

London Heathrow

Tue 12/1

12:15-21:45

2 stops17h 30m

£914

Flights are sorted by cheapest return flights first.

Deals found on 3/8

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 £464). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of £1,184). 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?

Airfare is below average for this route at the moment.

Ontario to London Heathrow Airport flights typically cost between £658 and £782 in November.
The cheapest return price found within the last 5 days was £548 on United Airlines (9 Nov–12 Nov).

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, JetBlue, and United Airlines can get you from Ontario to London Heathrow Airport in just under 14h 06m. Your travel time can differ by up to 8h 14m. 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 £464). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of £1,184). 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
Gatwick
Luton
Wembley
Slough
Ilford
Hayes
Croydon
Colchester
Eastbourne
Brentford
Northampton
Watford
Swindon
Southend-on-Sea
Enfield
Kingston upon Thames
Southall
Poole

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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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