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Cheap flights from Ontario to London from £182

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 31/3. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LON
6 Mar — 13 Mar1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from Ontario to London

Enter your travel dates to find the best prices.

Cheapest flights from Ontario to London
Explore the most affordable flight options available from Ontario to London. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 4 February 2026.

Thu 5/307:30
ONT
-
LHR
1 stop19h 00m
KLM
Thu 12/306:30
LHR
-
ONT
2 stops17h 42m
KLM
Deal found 3/2£463
Thu 5/306:00
ONT
-
LHR
2 stops17h 05m
Delta
Thu 12/306:30
LHR
-
ONT
2 stops21h 30m
Delta
Deal found 3/2£468
Wed 15/411:53
ONT
-
LHR
1 stop16h 17m
Delta
Tue 5/511:45
LHR
-
ONT
2 stops18h 52m
Delta
Deal found 3/2£476
Tue 3/314:39
ONT
-
LHR
1 stop13h 01m
British Airways
Mon 9/314:25
LHR
-
ONT
1 stop14h 42m
British Airways
Deal found 3/2£477
Mon 2/314:39
ONT
-
LHR
1 stop13h 01m
British Airways
Mon 9/314:25
LHR
-
ONT
1 stop14h 42m
British Airways
Deal found 2/2£478
Tue 3/307:30
ONT
-
LHR
1 stop19h 00m
KLM
Mon 9/306:30
LHR
-
ONT
2 stops17h 42m
KLM
Deal found 3/2£483
Thu 5/313:40
ONT
-
LHR
1 stop14h 20m
United Airlines
Tue 10/311:35
LHR
-
ONT
1 stop16h 15m
United Airlines
Deal found 3/2£484
Thu 12/313:40
ONT
-
LHR
1 stop15h 20m
United Airlines
Wed 18/310:05
LHR
-
ONT
1 stop14h 36m
United Airlines
Deal found 2/2£485
Thu 5/306:15
ONT
-
LHR
2 stops16h 15m
Multiple Airlines
Thu 12/311:10
LHR
-
ONT
2 stops18h 08m
Multiple Airlines
Deal found 3/2£486
Sat 7/306:00
ONT
-
LHR
2 stops20h 30m
Virgin Atlantic
Sat 14/311:40
LHR
-
ONT
2 stops18h 08m
Virgin Atlantic
Deal found 3/2£487
Thu 23/414:20
ONT
-
LGW
2 stops17h 40m
Delta
Mon 4/510:25
LGW
-
ONT
2 stops20h 12m
Delta
Deal found 3/2£603
Thu 26/206:00
ONT
-
LGW
2 stops20h 50m
Iberia
Wed 4/319:40
LGW
-
ONT
2 stops26h 09m
Iberia
Deal found 2/2£604

Find flight deals from Ontario to London

Discover tips and strategies to find the most affordable flight options for your journey from Ontario (ONT) to London (LON). 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 4 February 2026.

Round-trip from

£463

One-way from

£182

Popular in

June

Cheapest in

February

Average price

£478
KLM
  • KLM
  • 5/3-12/3
  • 3 total stops
  • 36h 42m total
  • Ontario to London
Search Deals
31/3
  • 31/3
  • 2 total stops
  • 19h 45m total
  • Ontario to London
Search Deals
Highest demand for flights based on searches. 16% potential increase in price (£78 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease (£14 potential savings vs. average return price).
Search Deals
Average for round-trip flights in February 2026
Search Deals

Cheapflights Fare Finder

 
Customise your flight search to find flights from Ontario to London 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 4 February 2026.
Use the filters below to find and compare flights from Ontario to London that are best for you.

Fly from

Ontario

Fly to

London

Route

Depart

Return

Price

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Thu 5/3

07:30-10:30

1 stop19h 00m

London Heathrow

Thu 12/3

14:30-22:33

1 stop15h 03m

£484

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 7/3

13:40-13:30

2 stops15h 50m

London Heathrow

Sat 14/3

13:45-22:57

1 stop16h 12m

£484

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 3/3

13:50-12:00

1 stop14h 10m

London Heathrow

Tue 24/3

13:35-22:18

1 stop15h 43m

£485

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 1/3

13:50-12:00

1 stop14h 10m

London Heathrow

Sun 8/3

13:35-22:18

1 stop15h 43m

£485

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 7/3

06:00-10:30

2 stops20h 30m

London Heathrow

Sat 14/3

11:40-22:48

2 stops18h 08m

£487

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 5/4

13:34-12:20

1 stop14h 46m

London Heathrow

Tue 14/4

14:10-22:26

1 stop16h 16m

£497

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 15/2

13:15-11:40

1 stop14h 25m

London Heathrow

Tue 24/2

14:30-22:37

1 stop16h 07m

£506

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 16/3

13:50-09:40

1 stop12h 50m

London Heathrow

Mon 6/4

15:30-21:50

3 stops38h 20m

£511

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 23/3

13:40-12:00

1 stop15h 20m

London Heathrow

Mon 30/3

14:50-20:36

1 stop13h 46m

£533

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 6/4

13:34-12:20

1 stop14h 46m

London Heathrow

Mon 20/4

14:50-20:36

1 stop13h 46m

£533

Flights are sorted by cheapest return flights first.

Deals found on 3/2

Showing 1-10 of 59 results
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Best time to book a flight from Ontario to London

Have a flexible travel schedule? Discover the best time to fly to London 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

What is the cheapest month to book a flight from Ontario to London?

Currently, October is the cheapest month in which you can book a flight from Ontario to London (average of £162). Flying from Ontario to London in June is currently the most expensive (average of £419). 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.

What’s the top stopover airport for flights from Ontario to London?

Share of one-stop return flights from Ontario to London chosen by Cheapflights users in the past 12 months, using the same stopover each way.

Dallas (DFW) – chosen by Cheapflights users on 40% of one-stop itineraries from Ontario to London on Cheapflights.

What’s the cheapest stopover airport for flights from Ontario to London?

Average return fare for one-stop flights from Ontario to London, chosen by Cheapflights users in the past 12 months, with the same stopover each way.

Phoenix (PHX) is the most affordable one-stop option, with an average return flight price of £464.

What’s the fastest stopover option from Ontario to London?

Shortest average travel time for one-stop one-way flights from Ontario to London, based on itineraries clicked by Cheapflights users over the past 12 months, grouped by stopover airport.

Flights via Phoenix (PHX) have the shortest average one-way travel time for one-stop routes: 12h 15m.

Which airport typically offers the quickest stopover for flights from Ontario to London?

Average stopover duration for one-stop one-way flights from Ontario to London, chosen by Cheapflights users in the last 12 months, grouped by stopover airport.

Flights via Phoenix (PHX) offer the fastest connection on this route, with an average stopover time of 1h 28m.

Related info for your journey

Find useful and relevant information for your journey from Ontario to London. 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?

    Ontario (ONT), located 3.1 mi from the city center, is the airport you fly out of when you book flights from Ontario to London. 0 airlines have flights from Ontario to London on a regular basis. Booking flights from Ontario to London should not be difficult; the airport handles an average of 0 outbound flights to London per day.

  • How long is the flight from Ontario to London?

    Airlines like KLM, United Airlines, and Virgin Atlantic fly from Ontario to London in about 15h 50m. The time it takes to get you to your destination can typically vary by up to 4h 40m. The distance between Ontario and London is about 5407 mi. This flight may include one or multiple stops.

  • What are the most popular routes from Ontario to London?

    When deciding which route to take from Ontario to London consider Ontario - London Heathrow, Ontario - London Gatwick or Ontario - London City as they are the most popular.

  • Can I find deals for flights from Ontario to London that include hotel bookings?

    Yes. In addition to deals on Ontario to London flights, Cheapflights offers holiday packages that include both flights and hotel.

  • How can I find direct flights from Ontario to London?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Ontario to London.

  • Can I find deals for business class flights from Ontario to London?

    Yes. Cheapflights offers flight deals from Ontario to London 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?

    Currently, October is the cheapest month in which you can book a flight from Ontario to London (average of £162). Flying from Ontario to London in June is currently the most expensive (average of £419). 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?

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Why should you use Cheapflights to find cheap flight tickets from Ontario to London?

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Can Cheapflights find flights from Ontario to London with no change fees?

Yes! Cheapflights helps users easily find flights from Ontario to London with no change fees.

Can Cheapflights notify me if prices for flights from Ontario to London become cheaper?

Yes! Start tracking prices for Ontario to London flights today and get alerted whenever prices for these flights change. To access this feature, click the bell icon next to the flight deals above, which will prompt you for a valid email address to receive your alerts.

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