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Cheap flights from Ontario to London Heathrow Airport from £235

ONT — LHR
3 Nov — 10 Nov1
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

Wed 4/1106:30 -
2 stops29h 00m
Mon 9/1112:15 -
2 stops19h 36m
Deal found 30/9£603
Sat 14/1106:25 -
2 stops29h 05m
Sat 21/1112:15 -
2 stops19h 59m
Deal found 30/9£612
Mon 9/1106:25 -
2 stops29h 05m
Fri 13/1112:15 -
2 stops19h 36m
Deal found 30/9£624
Mon 26/1006:15 -
2 stops21h 35m
Mon 2/1120:35 -
2 stops35h 16m
Deal found 29/9£634
Thu 12/1106:30 -
2 stops20h 20m
Mon 16/1120:35 -
2 stops35h 16m
Deal found 1/10£637
Mon 9/1106:30 -
2 stops20h 20m
Wed 18/1112:15 -
2 stops19h 36m
Deal found 30/9£640
Wed 11/1117:07 -
3 stops33h 43m
Mon 16/1120:35 -
2 stops35h 16m
Deal found 30/9£647

Find flight deals from Ontario to Heathrow

Round-trip from

£568

One-way from

£235

Popular in

June

Cheapest in

November

Average price

£707
United Airlines
  • United Airlines
  • 2/3-5/3
  • 3 total stops
  • 48h 44m total
  • Ontario to London
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British Airways
  • British Airways
  • 7/3-31/12
  • 1 total stop
  • 12h 33m total
  • Ontario to London
Search Deals
Highest demand for flights based on searches. 23% potential increase in price (£191 potential increase over avg. return price).
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Cheapest flight prices on average. 4% potential price decrease (£28 potential savings vs. average return price).
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Average for round-trip flights in October 2026
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Cheapflights Fare Finder

 
Use the filters below to find and compare flights from Ontario to London Heathrow Airport that are best for you.

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Route

Depart

Return

Price

Cheapest return flight

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Fri 16/10

23:05-20:45

1 stop13h 40m

London Heathrow

Wed 31/12

00:00-15:00

Nonstop0h 00m

£248

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Wed 11/11

06:00-07:25

1 stop17h 25m

London Heathrow

Wed 31/12

00:00-15:00

Nonstop0h 00m

£350

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Sat 14/11

13:35-07:25

1 stop33h 50m

London Heathrow

Wed 31/12

00:00-15:00

Nonstop0h 00m

£359
Fastest return journey

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Sun 22/11

13:29-09:40

1 stop12h 11m

London Heathrow

Wed 31/12

00:00-15:00

Nonstop0h 00m

£396

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Wed 18/11

06:00-07:40

1 stop17h 40m

London Heathrow

Wed 31/12

00:00-15:00

Nonstop0h 00m

£505

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Sat 28/11

18:37-11:15

1 stop32h 38m

London Heathrow

Wed 31/12

00:00-15:00

Nonstop0h 00m

£523

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Wed 4/11

10:05-10:50

2 stops16h 45m

London Heathrow

Wed 31/12

00:00-15:00

Nonstop0h 00m

£543

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Wed 25/11

08:50-10:50

2 stops18h 00m

London Heathrow

Wed 31/12

00:00-15:00

Nonstop0h 00m

£543

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Thu 10/12

05:45-07:40

1 stop17h 55m

London Heathrow

Wed 31/12

00:00-15:00

Nonstop0h 00m

£551

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Thu 12/11

06:30-10:50

2 stops20h 20m

London Heathrow

Wed 31/12

00:00-15:00

Nonstop0h 00m

£581

Flights are sorted by cheapest return flights first.

Deals found on 2/10

Showing 1-10 of 22 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

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 £547). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of £1,202). 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 £643 and £716 in March.
The cheapest return price found within the last 5 days was £568 on United Airlines (2 Mar–5 Mar).

Related info for your journey

  • 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, KLM, and United Airlines can get you from Ontario to London Heathrow Airport in just under 12h 11m. Your travel time can differ by up to 7h 49m. 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 £547). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of £1,202). 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
Gatwick
Wembley
Slough
Ilford
Hayes
Croydon
Northampton
Colchester
Eastbourne
Enfield
Brentford
Southend-on-Sea
Barnet
Southall
Watford
Stratford-upon-Avon
Kingston upon Thames

Browse thousands of different options on Cheapflights for your next trip

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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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