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Cheap flights from Ontario to London from £291

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 2/3. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LON
13 Nov — 20 Nov1
1 adult
1 adult, Economy

Find 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 14 October 2025.

Tue 2/1213:20ONT - LHR
1 stop12h 40mVirgin Atlantic
Tue 16/1210:45LHR - ONT
1 stop21h 13mVirgin Atlantic
Deal found 13/10£442
Sun 19/1016:49ONT - LHR
1 stop12h 01mBritish Airways
Tue 4/1115:00LHR - ONT
1 stop15h 29mBritish Airways
Deal found 13/10£461
Mon 13/1016:49ONT - LHR
1 stop12h 01mBritish Airways
Tue 28/1015:00LHR - ONT
1 stop14h 42mBritish Airways
Deal found 13/10£465
Mon 13/1016:49ONT - LHR
1 stop12h 01mAmerican Airlines
Tue 28/1015:00LHR - ONT
1 stop14h 42mAmerican Airlines
Deal found 12/10£466
Wed 22/1010:57ONT - LHR
1 stop14h 03mBritish Airways
Wed 5/1110:05LHR - ONT
1 stop16h 16mBritish Airways
Deal found 12/10£466
Wed 22/1007:05ONT - LHR
1 stop22h 25mVirgin Atlantic
Tue 4/1106:30LHR - ONT
2 stops24h 11mVirgin Atlantic
Deal found 13/10£467
Tue 11/1106:00ONT - LHR
2 stops18h 45mDelta
Thu 20/1108:55LHR - ONT
2 stops22h 09mDelta
Deal found 13/10£469
Tue 21/1016:49ONT - LHR
1 stop12h 01mBritish Airways
Tue 28/1015:00LHR - ONT
1 stop14h 42mBritish Airways
Deal found 13/10£471
Mon 29/1222:29ONT - LHR
1 stop23h 56mDelta
Wed 28/112:30LHR - ONT
1 stop16h 44mDelta
Deal found 13/10£472
Tue 18/1117:49ONT - LHR
2 stops18h 21mDelta
Wed 26/1116:35LHR - ONT
2 stops35h 07mDelta
Deal found 11/10£475
Mon 13/1007:05ONT - LHR
1 stop16h 10mVirgin Atlantic
Tue 28/1014:45LHR - ONT
1 stop14h 56mVirgin Atlantic
Deal found 12/10£477
Tue 11/1107:00ONT - LCY
2 stops21h 50mMultiple Airlines
Thu 20/1109:40LCY - ONT
2 stops21h 11mMultiple Airlines
Deal found 13/10£519

Cheap 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 14 October 2025.

Round-trip from

£442

One-way from

£291

Popular in

June

Cheapest in

October

Average price

£508
Virgin Atlantic
  • Virgin Atlantic
  • 2/12-16/12
  • 2 total stops
  • 41h 13m total
  • Ontario to London
Search Deals
Air Canada
  • Air Canada
  • 2/3
  • 2 total stops
  • 17h 30m total
  • Ontario to London
Search Deals
Highest demand for flights based on searches. 12% potential increase in price (£64 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease (£15 potential savings vs. average return price).
Search Deals
Average for round-trip flights in October 2025
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 14 October 2025.
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

Wed 26/11

06:00-10:00

1 stop20h 00m

London Heathrow

Wed 3/12

09:00-23:04

2 stops22h 04m

£466

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 11/11

07:05-06:25

1 stop15h 20m

London Heathrow

Tue 18/11

11:30-23:04

2 stops19h 34m

£466

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 11/11

07:05-07:50

1 stop16h 45m

London Heathrow

Tue 18/11

12:20-22:55

1 stop18h 35m

£472

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 31/12

06:38-10:30

1 stop19h 52m

London Heathrow

Tue 3/2

14:45-22:38

1 stop15h 53m

£472

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 30/12

07:05-07:50

1 stop16h 45m

London Heathrow

Wed 28/1

12:30-21:14

1 stop16h 44m

£472

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 19/11

13:20-10:00

1 stop12h 40m

London Heathrow

Tue 25/11

12:30-23:04

1 stop18h 34m

£472

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 29/12

22:29-06:25

1 stop23h 56m

London Heathrow

Fri 30/1

12:30-21:14

1 stop16h 44m

£472

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 31/12

13:15-10:00

1 stop12h 45m

London Heathrow

Thu 29/1

10:45-16:19

1 stop13h 34m

£472

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 2/12

06:00-06:50

2 stops16h 50m

London Heathrow

Tue 16/12

11:20-23:58

2 stops20h 38m

£475

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 18/11

11:48-10:30

1 stop14h 42m

London Heathrow

Wed 26/11

20:00-19:42

2 stops31h 42m

£475

Flights are sorted by cheapest return flights first.

Deals found on 13/10

Showing 1-10 of 60 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 £184). Flying from Ontario to London in June is currently the most expensive (average of £423). 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 is the cheapest time of day to fly from ONT to LON?

Find hourly flight availability from Ontario to London. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 14 October 2025.

One of the essential ways to save on airfare from Ontario to London is to remain as flexible as possible. Flights that are in the evening tend to be the most expensive. A flight in the afternoon could potentially save you up to 28% on airfare.

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 50% 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 £476.

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, KLM, and Iberia fly from Ontario to London in about 16h 45m. The time it takes to get you to your destination can typically vary by up to 3h 55m. The distance between Ontario and London is about 5407 mi. This flight may include one or multiple stops.

  • What are the cheapest airlines to fly from Ontario to London one-way?

    £302 is the cheapest one-way deal found within the past few days, from United Airlines. You may also be able to find cheap deals on Delta and Iberia, with prices starting from £302 and £312, respectively.

  • 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 £184). Flying from Ontario to London in June is currently the most expensive (average of £423). 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

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Fly with Cheapflights

Find the best flight deals on Cheapflights, where travellers can enjoy low prices and a wide availability of flights to their desired destinations.

How does Cheapflights help users find flights from Ontario to London?

Cheapflights helps you search for flights from Ontario to London via 900+ travel sites so you don’t have to. After performing a flight search, users can also filter their flight selection by filtering for price, number of stops, airlines, and so on.

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

Cheapflights taps into our reliable network of hundreds of airlines and travel agencies to find the best deals for flights from Ontario to London for you. Better yet — we are completely free to use.

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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