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Cheap flights from London to Ontario from £275

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 9/3. Fares are subject to change and may not be available on all flights or dates of travel.
LON — ONT
16 Mar — 23 Mar1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from London to Ontario

Enter your travel dates to find the best prices.

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 14 February 2026.

Tue 3/306:35
LHR
-
ONT
2 stops19h 06m
United Airlines
Tue 10/313:50
ONT
-
LHR
1 stop12h 50m
United Airlines
Deal found 12/2£369
Sat 28/206:30
LHR
-
ONT
2 stops19h 11m
United Airlines
Mon 9/313:50
ONT
-
LHR
1 stop12h 50m
United Airlines
Deal found 12/2£370
Mon 30/316:25
LHR
-
ONT
1 stop15h 34m
British Airways
Mon 6/412:22
ONT
-
LHR
1 stop14h 28m
British Airways
Deal found 13/2£387
Sat 28/206:30
LHR
-
ONT
2 stops19h 11m
United Airlines
Sun 8/313:50
ONT
-
LHR
1 stop12h 50m
United Airlines
Deal found 11/2£387
Wed 12/816:25
LHR
-
ONT
1 stop15h 43m
British Airways
Thu 27/816:54
ONT
-
LHR
1 stop14h 11m
British Airways
Deal found 12/2£390
Tue 17/309:55
LHR
-
ONT
1 stop16h 50m
British Airways
Tue 24/310:56
ONT
-
LHR
1 stop14h 19m
British Airways
Deal found 14/2£394
Thu 19/216:30
LHR
-
ONT
1 stop15h 29m
British Airways
Thu 26/214:39
ONT
-
LHR
1 stop13h 01m
British Airways
Deal found 11/2£395
Wed 10/617:45
LHR
-
ONT
1 stop31h 31m
Virgin Atlantic
Wed 19/807:00
ONT
-
LHR
1 stop21h 10m
Virgin Atlantic
Deal found 14/2£397
Wed 12/812:55
LHR
-
ONT
1 stop19h 13m
Finnair
Thu 27/806:10
ONT
-
LHR
1 stop18h 50m
Finnair
Deal found 13/2£398
Wed 8/410:05
LHR
-
ONT
1 stop14h 17m
British Airways
Thu 23/410:59
ONT
-
LHR
1 stop13h 06m
British Airways
Deal found 12/2£398
Thu 19/207:50
LCY
-
ONT
2 stops24h 09m
British Airways
Sun 8/323:58
ONT
-
LCY
2 stops31h 37m
British Airways
Deal found 12/2£470
Thu 19/207:50
LCY
-
ONT
2 stops24h 09m
British Airways
Sat 7/323:58
ONT
-
LCY
2 stops48h 52m
British Airways
Deal found 12/2£477

Find 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 14 February 2026.

Round-trip from

£369

One-way from

£275

Popular in

July

Cheapest in

September

Average price

£409
United Airlines
  • United Airlines
  • 3/3-10/3
  • 3 total stops
  • 31h 56m total
  • London to Ontario
Search Deals
9/3
  • 9/3
  • 2 total stops
  • 30h 28m total
  • London to Ontario
Search Deals
Highest demand for flights based on searches. 13% potential increase in price (£58 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease (£17 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 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 858,174 searches. Data last updated 14 February 2026.
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

Sat 28/2

06:30-17:41

2 stops19h 11m

Ontario

Sun 8/3

13:50-09:40

1 stop12h 50m

£387

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Tue 3/3

10:00-22:00

1 stop20h 00m

Ontario

Tue 10/3

13:40-12:00

1 stop15h 20m

£393

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Mon 27/4

06:30-17:15

2 stops18h 45m

Ontario

Sat 9/5

07:05-07:55

2 stops16h 50m

£405

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Wed 4/3

08:20-16:19

1 stop15h 59m

Ontario

Tue 10/3

10:56-08:15

1 stop14h 19m

£407

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Wed 25/2

11:45-19:45

1 stop16h 00m

Ontario

Wed 4/3

14:39-11:40

1 stop13h 01m

£407

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Wed 12/8

16:25-00:08

1 stop15h 43m

Ontario

Tue 1/9

16:54-15:05

1 stop14h 11m

£408

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Tue 24/2

11:45-19:45

1 stop16h 00m

Ontario

Mon 2/3

14:39-11:40

1 stop13h 01m

£409

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Mon 30/3

10:05-16:22

1 stop14h 17m

Ontario

Sat 25/4

10:55-08:35

1 stop13h 40m

£409

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Fri 6/3

11:55-22:29

1 stop18h 34m

Ontario

Mon 9/3

07:00-10:00

1 stop20h 00m

£410

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Fri 27/2

16:30-23:59

1 stop15h 29m

Ontario

Tue 3/3

14:39-11:40

1 stop13h 01m

£411

Flights are sorted by cheapest return flights first.

Deals found on 13/2

Showing 1-10 of 60 results
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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 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 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 return flight from London to Ontario. Price data was last updated on 6 February 2026.

To ensure you get the cheapest price possible for a flight from London to Ontario, you should look to book at least 81 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

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 £235). Flying from London to Ontario in July is currently the most expensive (average of £384). 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 London to Ontario?

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

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

Dallas (DFW) – chosen by Cheapflights users on 29% of one-stop itineraries from London to Ontario on Cheapflights.

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

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

Lisbon (LIS) is the most affordable one-stop option, with an average return flight price of £387.

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

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

Flights via Denver (DEN) have the shortest average one-way travel time for one-stop routes: 13h 54m.

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

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

Flights via Seattle (SEA) offer the fastest connection on this route, with an average stopover time of 1h 20m.

Reviews of airlines servicing Ontario

Get insights into the airlines that provide service to Ontario. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Ontario. Reviews last updated 14 February 2026.
Read through reviews of airlines operating flights from London to Ontario, such as Finnair, Virgin Atlantic, andUnited Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Finnair
7.6
Good
1,362 reviews
Check prices

Food

6.7

Crew

8.2

Entertainment

6.9

Overall

7.6

Boarding

7.7

Comfort

7.4

Reviews

1 / 20
2.0
Mediocre

Vlad-Valentin,Jan 2026

LHR - YVR

baggage allowance was different between the outgoing and inbound flights
Finnair
7.6
Good
1,362 reviews
Finnair
7.6
Good
1,362 reviews
Check prices

Food

6.7

Crew

8.2

Entertainment

6.9

Overall

7.6

Boarding

7.7

Comfort

7.4

Reviews

1 / 20
2.0
Mediocre

Vlad-Valentin,Jan 2026

LHR - YVR

baggage allowance was different between the outgoing and inbound flights
Virgin Atlantic
7.5
Good
678 reviews
Finnair
7.6
Good
1,362 reviews
Check prices

Food

6.7

Crew

8.2

Entertainment

6.9

Overall

7.6

Boarding

7.7

Comfort

7.4

Reviews

1 / 20
2.0
Mediocre

Vlad-Valentin,Jan 2026

LHR - YVR

baggage allowance was different between the outgoing and inbound flights
United Airlines
7.4
Good
9,296 reviews
Finnair
7.6
Good
1,362 reviews
Check prices

Food

6.7

Crew

8.2

Entertainment

6.9

Overall

7.6

Boarding

7.7

Comfort

7.4

Reviews

1 / 20
2.0
Mediocre

Vlad-Valentin,Jan 2026

LHR - YVR

baggage allowance was different between the outgoing and inbound flights
Lufthansa
6.8
Okay
7,785 reviews
Finnair
7.6
Good
1,362 reviews
Check prices

Food

6.7

Crew

8.2

Entertainment

6.9

Overall

7.6

Boarding

7.7

Comfort

7.4

Reviews

1 / 20
2.0
Mediocre

Vlad-Valentin,Jan 2026

LHR - YVR

baggage allowance was different between the outgoing and inbound flights
British Airways
6.7
Okay
7,741 reviews
Finnair
7.6
Good
1,362 reviews
Check prices

Food

6.7

Crew

8.2

Entertainment

6.9

Overall

7.6

Boarding

7.7

Comfort

7.4

Reviews

1 / 20
2.0
Mediocre

Vlad-Valentin,Jan 2026

LHR - YVR

baggage allowance was different between the outgoing and inbound flights

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?

    Most people fly into Ontario (ONT) if they book a flight to Ontario from London. On average, Ontario has 0 inbound flights from London per day from 6 airlines. Ontario is conveniently located just 3.1 mi from Ontario’s city center.

  • How long is the flight from London to Ontario?

    Airlines like United Airlines, Delta, and British Airways fly from London to Ontario in about 15h 59m. The time it takes to get you to your destination can typically vary by up to 3h 12m. The distance from London to Ontario is about 5407 mi. When browsing for deals, the options you’ll see will be for both direct flights and flights with stops.

  • What are the cheapest airlines flying from London to Ontario round-trip?

    According to our current data, Finnair (£275), United Airlines (£364), and Virgin Atlantic (£369) offers the cheapest pricing from London to Ontario. You may be able to fly from London to Ontario for 46% less than the average price by searching for these airlines.

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

    The most popular route from London to Ontario is London Heathrow - Ontario. You may also consider London Gatwick - Ontario or London City - 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 holiday 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 £235). Flying from London to Ontario in July is currently the most expensive (average of £384). 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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Alternative routes for London to Ontario

See prices for flight routes from nearby airports that may be better suited for you.
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Top 6 airlines flying from London to Ontario

Discover the top 6 airlines 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 858,174 searches. Data last updated 14 February 2026.
AirlineCheapestAverageFlexibilityOn-time
FinnairCheapest£275Average£431FlexibilityNo cancel feeOn-time76%
Search Finnair flights
United AirlinesCheapest£364Average£456FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Virgin AtlanticCheapest£369Average£491FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
British AirwaysCheapest£377Average£461FlexibilityNo cancel feeOn-time70%
Search British Airways flights
KLMCheapest£388Average£606FlexibilityNo cancel feeOn-time75%
Search KLM flights
LufthansaCheapest£417Average£571FlexibilityNo cancel feeOn-time76%
Search Lufthansa flights

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 London to Ontario?

When you search for this flight from London to Ontario, Cheapflights searches on 900+ travel sites to save you time finding great flight deals online. Additionally, we offer filter features so you can choose a preferred cabin class or airline, see different price ranges, and much more so you can book the flight for you.

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

Cheapflights helps you find that perfect flight to Ontario from London by searching from hundreds of airlines and agencies you know and love. We are also free to use, in case you were wondering!

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

Cheapflights does show flights with no change fees to all users. To see these options for flights from London to Ontario, users can toggle the no change fees filter when performing a flight search.

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

Yes, Cheapflights offers price alerts on London to Ontario flights so you can book your travel at the perfect time. Price Alerts can be enabled by clicking the bell icon next to the flight deals above and providing your email address where you want to receive the alerts.

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