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Cheap flights from Ontario to London from £276

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 26/7. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LON
25 Apr — 2 May1
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 26 March 2026.

Sun 5/411:59
ONT
-
LHR
1 stop16h 11m
Virgin Atlantic
Tue 21/406:30
LHR
-
ONT
2 stops24h 07m
Virgin Atlantic
Deal found 22/3£627
Wed 15/417:55
ONT
-
LHR
1 stop13h 40m
Delta
Tue 5/509:55
LHR
-
ONT
2 stops19h 05m
Delta
Deal found 24/3£630
Sun 5/406:00
ONT
-
LHR
2 stops16h 45m
Delta
Tue 21/406:15
LHR
-
ONT
2 stops18h 10m
Delta
Deal found 22/3£632
Sun 23/807:00
ONT
-
LHR
2 stops18h 15m
Delta
Wed 9/906:30
LHR
-
ONT
2 stops18h 46m
Delta
Deal found 24/3£633
Tue 7/410:59
ONT
-
LHR
1 stop13h 06m
British Airways
Thu 16/416:10
LHR
-
ONT
1 stop13h 49m
British Airways
Deal found 23/3£634
Wed 18/1111:55
ONT
-
LHR
1 stop14h 35m
Delta
Fri 27/1106:20
LHR
-
ONT
2 stops24h 23m
Delta
Deal found 24/3£635
Sun 5/410:56
ONT
-
LHR
1 stop13h 09m
British Airways
Tue 21/410:05
LHR
-
ONT
1 stop14h 17m
British Airways
Deal found 22/3£636
Sun 23/805:45
ONT
-
LHR
1 stop21h 50m
United Airlines
Tue 8/909:30
LHR
-
ONT
2 stops20h 29m
United Airlines
Deal found 24/3£638
Wed 15/414:20
ONT
-
LGW
2 stops17h 40m
Delta
Tue 5/510:35
LGW
-
ONT
2 stops20h 02m
Delta
Deal found 24/3£638
Tue 14/406:00
ONT
-
LHR
2 stops16h 35m
Air Canada
Tue 21/415:05
LHR
-
ONT
2 stops29h 15m
Air Canada
Deal found 23/3£640
Tue 14/417:55
ONT
-
LHR
1 stop13h 40m
Virgin Atlantic
Wed 6/510:55
LHR
-
ONT
1 stop13h 30m
Virgin Atlantic
Deal found 22/3£641
Sun 5/417:09
ONT
-
LCY
2 stops15h 31m
Delta
Tue 21/409:20
LCY
-
ONT
2 stops19h 40m
Delta
Deal found 22/3£654

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 26 March 2026.

Round-trip from

£627

One-way from

£276

Popular in

July

Cheapest in

March

Average price

£487
Virgin Atlantic
  • Virgin Atlantic
  • 5/4-21/4
  • 3 total stops
  • 40h 18m total
  • Ontario to London
Search Deals
26/7
  • 26/7
  • 2 total stops
  • 35h 21m total
  • Ontario to London
Search Deals
Highest demand for flights based on searches. 23% potential increase in price (£131 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease (£19 potential savings vs. average return price).
Search Deals
Average for round-trip flights in March 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 26 March 2026.
Use the filters below to find and compare flights from Ontario to London that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest return flight

OntarioLondon

ONT - LGW

ONTLGW

Ontario

Wed 15/4

14:20-16:00

2 stops17h 40m

London Gatwick

Tue 5/5

10:35-22:37

2 stops20h 02m

£638

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 5/4

13:34-12:35

1 stop15h 01m

London Heathrow

Tue 21/4

14:50-20:36

1 stop13h 46m

£648

OntarioLondon

ONT - LCY

ONTLCY

Ontario

Sun 5/4

17:09-16:40

2 stops15h 31m

London City

Tue 21/4

09:20-21:00

2 stops19h 40m

£654

OntarioLondon

ONT - LGW

ONTLGW

Ontario

Wed 8/4

12:57-16:00

2 stops19h 03m

London Gatwick

Tue 21/4

10:35-22:37

2 stops20h 02m

£676

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 25/8

07:00-09:00

1 stop18h 00m

London Heathrow

Mon 7/9

10:00-21:59

1 stop19h 59m

£684

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 26/8

07:00-15:35

1 stop24h 35m

London Heathrow

Sat 12/9

18:35-11:04

2 stops24h 29m

£692

OntarioLondon

ONT - LGW

ONTLGW

Ontario

Tue 21/4

06:15-08:40

2 stops18h 25m

London Gatwick

Sun 3/5

12:20-23:46

2 stops19h 26m

£701

OntarioLondon

ONT - LGW

ONTLGW

Ontario

Thu 23/4

14:20-16:00

2 stops17h 40m

London Gatwick

Mon 4/5

10:25-22:37

2 stops20h 12m

£712

OntarioLondon

ONT - LGW

ONTLGW

Ontario

Wed 8/4

12:57-16:00

2 stops19h 03m

London Gatwick

Wed 22/4

10:25-21:00

2 stops18h 35m

£713

OntarioLondon

ONT - LGW

ONTLGW

Ontario

Thu 9/4

06:00-16:00

2 stops26h 00m

London Gatwick

Wed 22/4

10:25-21:00

2 stops18h 35m

£713

Flights are sorted by cheapest return flights first.

Deals found on 22/3

Showing 1-10 of 60 resultsSorted by cheapest first
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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 £166). Flying from Ontario to London in June is currently the most expensive (average of £418). 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?

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 £474.

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 Delta, United Airlines, and American Airlines fly from Ontario to London in about 15h 01m. The time it takes to get you to your destination can typically vary by up to 3h 24m. 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 £166). Flying from Ontario to London in June is currently the most expensive (average of £418). 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?

Book flights to London if you plan to visit one of these locations
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Ilford
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Watford
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Romford
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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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