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Ontario

$343+ Cheap flights from London (LON) to Ontario (ONT)

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 11/13. Fares are subject to change and may not be available on all flights or dates of travel.
LON — ONT
Nov 29 — Dec 61
Sat 11/29
Sat 12/6
1 adult, Economy
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Find cheap flights from London to Ontario with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

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3. Compare prices and book

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Cheapflights Tip: The best prices from London to Ontario are usually found in September or January, booked 81 days in advance, depart on a Tuesday or Wednesday and return on a Wednesday

Find flight deals from London to Ontario

Cheapest flights from London to Ontario
Explore the most affordable flight options available from London to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 30, 2025.

This Delta deal was found by Cheapflights users on 10/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/318:55 amLHR - ONT
1 stop33h 05mDelta
Mon 1/51:04 pmONT - LHR
1 stop34h 46mDelta
Deal found 10/27$617
This TravelUp deal was found by Cheapflights users on 10/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure TravelUp is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/1210:45 amLHR - ONT
1 stop21h 07mVirgin Atlantic
Thu 11/2011:48 amONT - LHR
1 stop14h 42mVirgin Atlantic
Deal found 10/30$620
This TravelUp deal was found by Cheapflights users on 10/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure TravelUp is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/1412:20 pmLHR - ONT
1 stop18h 35mVirgin Atlantic
Thu 12/412:12 pmONT - LHR
1 stop35h 38mVirgin Atlantic
Deal found 10/29$623
This Delta deal was found by Cheapflights users on 10/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/156:30 amLHR - ONT
2 stops21h 09mDelta
Mon 1/127:30 amONT - LHR
1 stop19h 00mDelta
Deal found 10/28$629
This Delta deal was found by Cheapflights users on 10/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/146:30 amLHR - ONT
2 stops24h 34mDelta
Thu 12/46:00 amONT - LHR
2 stops17h 05mDelta
Deal found 10/30$630
This Delta deal was found by Cheapflights users on 10/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/318:55 amLHR - ONT
1 stop18h 55mDelta
Sun 1/410:29 pmONT - LHR
2 stops28h 21mDelta
Deal found 10/27$639
This Delta deal was found by Cheapflights users on 10/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 12/1112:30 pmLHR - ONT
1 stop18h 34mDelta
Wed 12/247:05 amONT - LHR
1 stop20h 35mDelta
Deal found 10/30$641
This Delta deal was found by Cheapflights users on 10/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/1612:20 pmLHR - ONT
1 stop18h 27mDelta
Wed 12/2411:15 amONT - LHR
1 stop13h 45mDelta
Deal found 10/30$643
This Delta deal was found by Cheapflights users on 10/29. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/222:45 pmLHR - ONT
1 stop16h 04mDelta
Mon 1/53:30 pmONT - LHR
1 stop13h 20mDelta
Deal found 10/29$644
This American Airlines deal was found by Cheapflights users on 10/28. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/1712:30 pmLGW - ONT
2 stops31h 33mAmerican Airlines
Tue 12/26:11 amONT - LGW
2 stops17h 19mAmerican Airlines
Deal found 10/28$664
This Delta deal was found by Cheapflights users on 10/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/1510:00 amLCY - ONT
2 stops57h 13mDelta
Wed 12/316:38 amONT - LCY
2 stops40h 37mDelta
Deal found 10/30$665
This Delta deal was found by Cheapflights users on 10/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/1010:00 amLCY - ONT
2 stops39h 07mDelta
Mon 12/295:49 pmONT - LCY
2 stops55h 41mDelta
Deal found 10/30$685

Cheap flight deals from London to Ontario

Discover tips and strategies to find the most affordable flight options for your journey from London (LON) to Ontario (ONT). 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 October 30, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$559
(Virgin Atlantic)

One-way from

$343
(Trip.com)

Popular in

July

Cheapest in

September

Average price

$661
Provider with most accurate pricing for London (LON)-Ontario flight deals.
Search Deals
Provider most trusted by Cheapflights users for London (LON)-Ontario flights.
Search Deals
From London (LON) to Ontario
Search Deals
One-way flight from London (LON) to Ontario
Search Deals
Highest demand for flights based on searches. 22% potential increase in price ($212 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 6% potential price decrease ($48 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in October 2025
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from London to Ontario 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 2,558,603 searches. Data last updated October 30, 2025.
Use the filters below to find and compare flights from London to Ontario that are best for you.

Fly from

London

Fly to

Ontario

Route

Depart

Return

Price

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Thu 2/26

6:30 am-9:14 pm

2 stops22h 44m

Ontario

Mon 3/2

5:05 pm-10:00 am

1 stop32h 55m

$571

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Sat 3/21

3:05 pm-10:38 pm

1 stop14h 33m

Ontario

Sat 3/28

1:00 pm-8:50 am

1 stop12h 50m

$594

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Tue 1/6

2:45 pm-10:29 pm

1 stop15h 44m

Ontario

Tue 1/20

1:04 pm-11:40 am

1 stop14h 36m

$594

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Wed 4/1

11:20 am-5:15 pm

1 stop13h 55m

Ontario

Mon 4/6

1:00 pm-9:50 am

1 stop12h 50m

$594

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Fri 2/13

12:30 pm-9:14 pm

1 stop16h 44m

Ontario

Mon 2/23

1:00 pm-11:40 am

1 stop14h 40m

$594

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Mon 3/16

2:45 pm-10:38 pm

1 stop14h 53m

Ontario

Tue 3/31

1:00 pm-9:50 am

1 stop12h 50m

$597

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Thu 2/26

10:45 am-4:19 pm

1 stop13h 34m

Ontario

Mon 3/2

1:00 pm-10:00 am

1 stop13h 00m

$598

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Fri 4/3

11:20 am-5:15 pm

1 stop13h 55m

Ontario

Fri 4/10

1:00 pm-9:50 am

1 stop12h 50m

$604

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Wed 4/1

10:55 am-4:19 pm

1 stop13h 24m

Ontario

Fri 4/10

1:00 pm-9:50 am

1 stop12h 50m

$604

LondonOntario

LGW - ONT

LGWONT

London Gatwick

Thu 2/26

12:30 pm-1:57 pm

2 stops33h 27m

Ontario

Mon 3/2

4:59 pm-7:30 am

2 stops30h 31m

$616

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/30

Showing 1-10 of 60 results
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Compare providers for flights from London to Ontario

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from London to Ontario in October.
ProviderPrice AccuracyTrust Score*
FlightHubPrice Accuracy3 starsTrust Score*1 star
eDreamsPrice Accuracy3 starsTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on London-Ontario flights, users find the pricing of eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on London-Ontario flight deals on Cheapflights vs. eDreams >95% of the time. Price accuracy is based on data collected from London-Ontario flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on London-Ontario flights, Cheapflights users trust eDreams the most. eDreams has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for London-Ontario flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from London to Ontario

Have a flexible travel schedule? Discover the best time to fly to Ontario from London with our price prediction graph.
Estimated round-trip 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 London to Ontario

How far ahead should I book a flight from London to Ontario?

Use this chart to determine the optimal time to book a round-trip flight from London to Ontario. Price data was last updated on October 24, 2025.

Booking 81 days in advance of your planned departure date is, on average, the best time to get cheap flights from London to Ontario. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

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

Currently, September is the cheapest month in which you can book a flight from London to Ontario (average of $320). Flying from London to Ontario in July is currently the most expensive (average of $556). 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 LON to ONT?

Find hourly flight availability from London to Ontario. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated October 30, 2025.

A simple way to save on the total cost of your ticket is to fly from London to Ontario in the afternoon. If you’re flexible enough to do this you can expect to save up to 22% on your trip compared to booking a flight at noon.

How much does it cost to fly round-trip from London to Ontario?

Related info for your journey

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

    Ontario (ONT), located 3.1 mi from the city center, is the airport you fly into when you book flights from London to Ontario. 1 airline have flights to Ontario from London on a regular basis. Booking flights from London to Ontario should not be difficult; the airport handles an average of 0 inbound flights from London per day.

  • How long is the flight from London to Ontario?

    Airlines like Delta, KLM, and American Airlines fly from London to Ontario in about 14h 33m. The time it takes to get you to your destination can typically vary by up to 18h 54m. London and Ontario are separated by a distance of 5407 mi. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.

  • What is the cheapest airline to fly from London to Ontario round-trip?

    Cheapflights users have booked flights from London to Ontario round-trip from $560. This flight start at 24% lower than the current average price 3 months from now.

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

    For one-way options, check prices for British Airways. According to our data, you can fly for as low as $415. Users have also found prices from $429 and $452 on United Airlines and Delta, respectively.

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

    Most travelers choose London Heathrow - Ontario, London Gatwick - Ontario or London City - Ontario when deciding on the best route from London to Ontario.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from London to Ontario 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 London to Ontario?

    Currently, September is the cheapest month in which you can book a flight from London to Ontario (average of $320). Flying from London to Ontario in July is currently the most expensive (average of $556). 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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Top airline flying from London to Ontario

Discover the top airline that operate flights from London to Ontario. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated October 30, 2025.
AirlineCheapestAverageFlexibilityOn-time
United AirlinesCheapest$560Average$739FlexibilityNo cancel feeOn-time69%

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