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Cheap flights from Ontario to London Heathrow Airport from £311

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 7/6. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LHR
23 May — 30 May1
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 23 April 2026.

Mon 2/1107:00
ONT
-
LHR
1 stop17h 15m
Iberia
Wed 18/1106:15
LHR
-
ONT
2 stops24h 08m
Iberia
Deal found 20/4£660
Sun 23/814:00
ONT
-
LHR
1 stop17h 35m
KLM
Tue 8/906:30
LHR
-
ONT
2 stops17h 44m
KLM
Deal found 20/4£663
Mon 4/517:55
ONT
-
LHR
1 stop13h 40m
Virgin Atlantic
Tue 19/510:55
LHR
-
ONT
1 stop13h 22m
Virgin Atlantic
Deal found 20/4£664
Mon 10/809:55
ONT
-
LHR
2 stops19h 20m
Virgin Atlantic
Wed 19/811:45
LHR
-
ONT
2 stops18h 55m
Virgin Atlantic
Deal found 21/4£667
Sat 5/917:55
ONT
-
LHR
1 stop34h 15m
Delta
Tue 15/906:30
LHR
-
ONT
2 stops17h 44m
Delta
Deal found 21/4£668
Mon 10/813:00
ONT
-
LHR
1 stop13h 00m
Delta
Fri 21/806:15
LHR
-
ONT
2 stops17h 59m
Delta
Deal found 23/4£668
Tue 4/805:00
ONT
-
LHR
2 stops17h 30m
Air Canada
Wed 19/810:15
LHR
-
ONT
2 stops42h 37m
Air Canada
Deal found 20/4£670
Mon 11/517:50
ONT
-
LHR
1 stop13h 45m
Virgin Atlantic
Wed 20/510:55
LHR
-
ONT
1 stop13h 22m
Virgin Atlantic
Deal found 20/4£671
Mon 3/813:50
ONT
-
LHR
1 stop13h 20m
United Airlines
Thu 20/809:30
LHR
-
ONT
2 stops20h 29m
United Airlines
Deal found 22/4£672
Tue 4/805:00
ONT
-
LHR
2 stops17h 30m
Air Canada
Fri 21/814:05
LHR
-
ONT
2 stops38h 47m
Air Canada
Deal found 20/4£673
Mon 3/805:00
ONT
-
LHR
2 stops17h 35m
Air Canada
Wed 19/810:15
LHR
-
ONT
2 stops42h 37m
Air Canada
Deal found 20/4£673
Mon 4/510:59
ONT
-
LHR
1 stop13h 06m
British Airways
Tue 19/510:05
LHR
-
ONT
1 stop14h 17m
British Airways
Deal found 20/4£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 23 April 2026.

Round-trip from

£660

One-way from

£332

Popular in

June

Cheapest in

November

Average price

£518
Iberia
  • Iberia
  • 6/5-13/5
  • 3 total stops
  • 37h 13m total
  • Ontario to London
Search Deals
JetBlue
  • JetBlue
  • 22/9
  • 1 total stop
  • 15h 35m total
  • Ontario to London
Search Deals
Highest demand for flights based on searches. 26% potential increase in price (£169 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 5% potential price decrease (£26 potential savings vs. average return price).
Search Deals
Average for round-trip flights in April 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 23 April 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 10/8

07:00-07:15

1 stop16h 15m

London Heathrow

Wed 19/8

11:45-22:40

2 stops18h 55m

£663

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 14/9

21:10-20:45

1 stop15h 35m

London Heathrow

Sat 19/9

08:15-20:13

1 stop19h 58m

£826

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 5/5

07:05-13:15

1 stop22h 10m

London Heathrow

Tue 26/5

09:20-21:48

1 stop20h 28m

£827

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 18/8

17:26-15:05

1 stop13h 39m

London Heathrow

Tue 25/8

17:00-23:24

1 stop14h 24m

£833

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Thu 23/7

13:50-11:10

1 stop13h 20m

London Heathrow

Tue 4/8

13:40-21:55

1 stop16h 15m

£862

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Thu 23/7

06:20-14:00

1 stop23h 40m

London Heathrow

Sat 1/8

10:55-22:23

1 stop19h 28m

£914

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 17/5

13:30-11:10

1 stop13h 40m

London Heathrow

Sun 24/5

11:25-17:28

1 stop14h 03m

£930

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 26/5

13:29-11:00

1 stop13h 31m

London Heathrow

Tue 2/6

06:30-16:17

2 stops17h 47m

£947

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 15/7

13:50-11:10

1 stop13h 20m

London Heathrow

Mon 27/7

13:40-21:55

1 stop16h 15m

£983

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 12/6

13:18-09:40

1 stop12h 22m

London Heathrow

Tue 16/6

16:15-22:37

1 stop14h 22m

£983

Flights are sorted by cheapest return flights first.

Deals found on 22/4

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
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 £462). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of £1,021). 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?

    United Airlines, British Airways, and Delta can get you from Ontario to London Heathrow Airport in just under 13h 06m. Your travel time can differ by up to 2h 44m. 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 £462). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of £1,021). 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
Wembley
Croydon
Hounslow
Northampton
Luton
Gatwick
Ilford
Slough
Hayes
Brentford
Colchester
Watford
Kingston upon Thames
Romford
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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