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Cheap flights from Ontario to London from £232

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 15/11. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LON
5 Dec — 12 Dec1
1 adult
1 adult, Economy, 0 bags

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 5 November 2025.

Tue 2/1206:00ONT - LHR
1 stop20h 00mVirgin Atlantic
Tue 16/1210:45LHR - ONT
1 stop21h 13mVirgin Atlantic
Deal found 4/11£449
Tue 2/1212:40ONT - LHR
1 stop13h 50mDelta
Tue 9/1206:30LHR - ONT
2 stops24h 34mDelta
Deal found 4/11£466
Sun 9/1112:16ONT - LHR
1 stop15h 24mDelta
Tue 25/1108:55LHR - ONT
1 stop18h 47mDelta
Deal found 2/11£469
Mon 3/1111:48ONT - LHR
1 stop17h 02mDelta
Tue 25/1106:20LHR - ONT
2 stops18h 49mDelta
Deal found 2/11£473
Tue 18/1107:05ONT - LHR
1 stop16h 45mKLM
Thu 27/1106:30LHR - ONT
2 stops21h 12mKLM
Deal found 3/11£474
Sun 9/1112:53ONT - LHR
1 stop13h 07mIberia
Tue 25/1116:30LHR - ONT
1 stop15h 27mIberia
Deal found 3/11£475
Mon 10/1106:45ONT - LCY
2 stops25h 50mDelta
Thu 27/1109:20LCY - ONT
2 stops45h 30mDelta
Deal found 4/11£517
Mon 1/1207:00ONT - LCY
2 stops21h 55mMultiple Airlines
Wed 17/1209:50LCY - ONT
2 stops20h 59mMultiple Airlines
Deal found 4/11£594
Tue 2/1206:00ONT - LCY
2 stops27h 35mMultiple Airlines
Mon 15/1217:15LCY - ONT
2 stops36h 34mMultiple Airlines
Deal found 4/11£605
Wed 12/1106:00ONT - LGW
2 stops20h 55mMultiple Airlines
Wed 19/1111:55LGW - ONT
2 stops20h 01mMultiple Airlines
Deal found 4/11£708
Wed 31/1205:05ONT - LCY
3 stops20h 20mMultiple Airlines
Sun 11/117:40LCY - ONT
3 stops36h 18mMultiple Airlines
Deal found 3/11£743
Wed 3/1206:00ONT - LGW
2 stops20h 55mMultiple Airlines
Mon 8/1211:55LGW - ONT
2 stops19h 34mMultiple Airlines
Deal found 3/11£747

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 5 November 2025.

Round-trip from

£449

One-way from

£232

Popular in

June

Cheapest in

October

Average price

£559
Virgin Atlantic
  • Virgin Atlantic
  • 2/12-16/12
  • 2 total stops
  • 41h 13m total
  • Ontario to London
Search Deals
15/11
  • 15/11
  • 2 total stops
  • 32h 23m total
  • Ontario to London
Search Deals
Highest demand for flights based on searches. 12% potential increase in price (£66 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 November 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 5 November 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

Tue 18/11

12:16-11:40

1 stop15h 24m

London Heathrow

Thu 27/11

10:45-18:04

1 stop15h 19m

£479

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 9/1

05:05-07:55

2 stops18h 50m

London Heathrow

Sun 18/1

08:30-21:58

2 stops21h 28m

£480

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 2/12

06:00-10:00

1 stop20h 00m

London Heathrow

Tue 16/12

12:30-23:58

2 stops19h 28m

£483

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 17/2

05:00-09:40

1 stop20h 40m

London Heathrow

Sun 22/2

09:30-21:59

2 stops20h 29m

£486

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 7/12

14:53-12:15

1 stop13h 22m

London Heathrow

Sun 14/12

10:05-18:18

1 stop16h 13m

£487

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 7/12

07:05-06:25

1 stop15h 20m

London Heathrow

Thu 25/12

08:55-19:50

1 stop18h 55m

£487

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 27/2

06:00-07:05

2 stops17h 05m

London Heathrow

Tue 3/3

06:30-22:40

2 stops24h 10m

£493

OntarioLondon

ONT - LCY

ONTLCY

Ontario

Tue 17/2

05:00-09:15

3 stops20h 15m

London City

Sun 22/2

17:15-19:54

2 stops34h 39m

£535

OntarioLondon

ONT - LCY

ONTLCY

Ontario

Mon 1/12

07:00-12:55

2 stops21h 55m

London City

Wed 17/12

09:50-22:49

2 stops20h 59m

£594

OntarioLondon

ONT - LCY

ONTLCY

Ontario

Tue 2/12

06:00-17:35

2 stops27h 35m

London City

Mon 15/12

17:15-21:49

2 stops36h 34m

£605

Flights are sorted by cheapest return flights first.

Deals found on 3/11

Showing 1-10 of 57 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 £192). Flying from Ontario to London in June is currently the most expensive (average of £431). 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 5 November 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.

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 £485.

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 Delta fly from Ontario to London in about 15h 24m. The time it takes to get you to your destination can typically vary by up to 4h 36m. 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?

    £301 is the cheapest one-way deal found within the past few days, from British Airways. You may also be able to find cheap deals on United Airlines and Delta, with prices starting from £305 and £327, 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 £192). Flying from Ontario to London in June is currently the most expensive (average of £431). 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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