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Cheap flights from Ontario to London Heathrow Airport from £237

ONT — LHR
30 Nov — 7 Dec1
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 2/1206:00 -
2 stops29h 30m
Wed 9/1212:15 -
2 stops18h 02m
Deal found 28/10£596
Thu 26/1106:45 -
2 stops28h 45m
Thu 3/1212:15 -
2 stops20h 02m
Deal found 28/10£602
Mon 7/1206:00 -
2 stops29h 30m
Tue 15/1212:15 -
2 stops18h 02m
Deal found 28/10£603
Tue 1/1219:06 -
3 stops31h 44m
Tue 8/1212:15 -
2 stops18h 02m
Deal found 30/10£628
Thu 3/1206:00 -
2 stops20h 50m
Mon 7/1220:35 -
2 stops33h 42m
Deal found 29/10£628
Tue 8/1206:00 -
2 stops20h 50m
Sun 13/1220:35 -
2 stops35h 45m
Deal found 30/10£629
Thu 3/1206:00 -
2 stops20h 50m
Sat 12/1206:00 -
2 stops25h 23m
Deal found 30/10£631
Fri 27/1110:55 -
3 stops26h 40m
Sun 6/1219:55 -
2 stops35h 28m
Deal found 27/10£633
Mon 16/1112:01 -
2 stops25h 39m
Sat 21/1106:40 -
2 stops25h 44m
Deal found 26/10£634
Wed 25/1106:45 -
2 stops28h 45m
Wed 2/1220:35 -
2 stops35h 42m
Deal found 28/10£635
Thu 3/1206:00 -
2 stops20h 50m
Thu 10/1212:15 -
3 stops27h 29m
Deal found 30/10£636

Find flight deals from Ontario to Heathrow

Round-trip from

£569

One-way from

£237

Popular in

June

Cheapest in

November

Average price

£699
United Airlines
  • United Airlines
  • 2/3-5/3
  • 3 total stops
  • 54h 35m total
  • Ontario to London
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Air Canada
  • Air Canada
  • 3/2-31/12
  • 2 total stops
  • 18h 05m total
  • Ontario to London
Search Deals
Highest demand for flights based on searches. 20% potential increase in price (£156 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease (£27 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

Sun 25/4

08:00-07:25

1 stop15h 25m

London Heathrow

Wed 31/12

00:00-15:00

Nonstop0h 00m

£249

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Fri 23/4

05:00-09:40

1 stop20h 40m

London Heathrow

Wed 31/12

00:00-15:00

Nonstop0h 00m

£287

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Fri 12/3

06:00-12:20

1 stop22h 20m

London Heathrow

Wed 31/12

00:00-15:00

Nonstop0h 00m

£332

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Fri 20/11

20:59-12:20

1 stop31h 21m

London Heathrow

Wed 31/12

00:00-15:00

Nonstop0h 00m

£454

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Mon 14/12

05:00-11:20

3 stops22h 20m

London Heathrow

Wed 31/12

00:00-15:00

Nonstop0h 00m

£475

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Wed 13/1

07:25-11:15

1 stop19h 50m

London Heathrow

Wed 31/12

00:00-15:00

Nonstop0h 00m

£511

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Wed 25/11

05:00-09:40

1 stop20h 40m

London Heathrow

Wed 31/12

00:00-15:00

Nonstop0h 00m

£528

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Tue 24/11

07:00-12:00

1 stop21h 00m

London Heathrow

Wed 31/12

00:00-15:00

Nonstop0h 00m

£528
Fastest return journey

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Mon 7/12

07:00-05:55

1 stop14h 55m

London Heathrow

Wed 31/12

00:00-15:00

Nonstop0h 00m

£528

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Sun 20/12

05:00-09:40

1 stop20h 40m

London Heathrow

Wed 31/12

00:00-15:00

Nonstop0h 00m

£540

Flights are sorted by cheapest return flights first.

Deals found on 27/10

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

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, December is the cheapest month in which you can book a flight from Ontario to London Heathrow Airport (average of £543). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of £1,188). 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

  • 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, British Airways, and Delta can get you from Ontario to London Heathrow Airport in just under 13h 16m. Your travel time can differ by up to 3h 28m. 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 £543). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of £1,188). 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
Luton
Milton Keynes
Slough
Wembley
Gatwick
Ilford
Hayes
Croydon
Northampton
Barnet
Eastbourne
Brentford
Southend-on-Sea
Southall
Enfield
Watford
Kingston upon Thames
Dagenham
Dover

Browse thousands of different options on Cheapflights for your next trip

Fly with Cheapflights

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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