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Cheap flights from London to Ontario from £346

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 28/8. Fares are subject to change and may not be available on all flights or dates of travel.
LON — ONT
9 Jul — 16 Jul1
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 9 June 2026.

Fri 4/906:55
LHR
-
ONT
2 stops21h 58m
United Airlines
Tue 8/913:56
ONT
-
LHR
1 stop13h 14m
United Airlines
Deal found 6/6£417
Wed 8/709:30
LHR
-
ONT
2 stops20h 25m
United Airlines
Mon 13/705:00
ONT
-
LHR
2 stops20h 20m
United Airlines
Deal found 8/6£418
Fri 20/1109:30
LHR
-
ONT
2 stops21h 36m
United Airlines
Sat 28/1105:00
ONT
-
LHR
1 stop20h 40m
United Airlines
Deal found 6/6£420
Mon 2/1109:30
LHR
-
ONT
2 stops21h 36m
United Airlines
Mon 16/1106:00
ONT
-
LHR
1 stop17h 25m
United Airlines
Deal found 5/6£421
Wed 1/709:30
LHR
-
ONT
2 stops21h 21m
Lufthansa
Thu 30/713:18
ONT
-
LHR
1 stop12h 22m
Lufthansa
Deal found 9/6£432
Sat 27/613:00
LHR
-
ONT
1 stop17h 50m
Lufthansa
Tue 30/613:50
ONT
-
LHR
1 stop16h 20m
Lufthansa
Deal found 6/6£434
Wed 8/713:40
LHR
-
ONT
1 stop16h 15m
Lufthansa
Mon 13/706:00
ONT
-
LHR
1 stop17h 25m
Lufthansa
Deal found 5/6£434
Sun 14/614:50
LHR
-
ONT
1 stop13h 56m
United Airlines
Sun 28/613:18
ONT
-
LHR
1 stop12h 22m
United Airlines
Deal found 7/6£440
Tue 16/614:50
LHR
-
ONT
1 stop13h 56m
United Airlines
Tue 28/716:20
ONT
-
LHR
1 stop13h 50m
United Airlines
Deal found 9/6£441
Sat 27/613:00
LHR
-
ONT
1 stop17h 50m
United Airlines
Sun 5/713:18
ONT
-
LHR
1 stop12h 22m
United Airlines
Deal found 6/6£443
Fri 26/613:40
LHR
-
ONT
1 stop16h 15m
United Airlines
Fri 3/713:18
ONT
-
LHR
1 stop15h 07m
United Airlines
Deal found 5/6£444
Mon 7/910:25
LGW
-
ONT
2 stops19h 27m
Air France
Wed 7/1012:00
ONT
-
LGW
2 stops20h 00m
Air France
Deal found 9/6£508

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 9 June 2026.

Round-trip from

£417

One-way from

£346

Popular in

May

Cheapest in

September

Average price

£503
United Airlines
  • United Airlines
  • 4/9-8/9
  • 3 total stops
  • 35h 12m total
  • London to Ontario
Search Deals
British Airways
  • British Airways
  • 28/8
  • 1 total stop
  • 15h 15m total
  • London to Ontario
Search Deals
Highest demand for flights based on searches. 10% potential increase in price (£45 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease (£12 potential savings vs. average return price).
Search Deals
Average for round-trip flights in June 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 9 June 2026.
Use the filters below to find and compare flights from London to Ontario that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest return flight

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Wed 1/7

13:00-22:37

1 stop17h 37m

Ontario

Mon 6/7

13:18-09:40

1 stop12h 22m

£441

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Sat 17/10

13:40-21:59

1 stop16h 19m

Ontario

Sat 31/10

13:00-09:40

1 stop13h 40m

£441
Fastest return journey

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Mon 29/6

16:15-22:37

1 stop14h 22m

Ontario

Tue 4/8

13:18-09:40

1 stop12h 22m

£441

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Fri 3/7

14:10-22:51

1 stop16h 41m

Ontario

Sun 12/7

13:18-09:40

1 stop12h 22m

£441

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Sun 6/9

13:40-21:59

1 stop16h 19m

Ontario

Thu 17/9

09:01-07:25

1 stop14h 24m

£441

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Thu 2/7

13:40-21:55

1 stop16h 15m

Ontario

Tue 7/7

13:18-09:40

1 stop12h 22m

£441

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Thu 2/7

10:35-17:54

1 stop15h 19m

Ontario

Wed 8/7

13:18-09:40

1 stop12h 22m

£511

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Sat 18/7

10:35-18:33

1 stop15h 58m

Ontario

Fri 24/7

13:18-12:25

1 stop15h 07m

£511

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Fri 21/8

16:15-22:59

1 stop14h 44m

Ontario

Sat 29/8

13:18-09:40

1 stop12h 22m

£514

LondonOntario

LCY - ONT

LCYONT

London City

Wed 12/8

20:15-16:24

2 stops28h 09m

Ontario

Mon 17/8

13:06-18:30

2 stops21h 24m

£515

Flights are sorted by cheapest return flights first.

Deals found on 4/6

Showing 1-10 of 60 resultsSorted by cheapest first
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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

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

Currently, March is the cheapest month in which you can book a flight from London to Ontario (average of £298). Flying from London to Ontario in May is currently the most expensive (average of £457). 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 41% 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 £394.

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 44m.

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 Dallas (DFW) offer the fastest connection on this route, with an average stopover time of 1h 36m.

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

To ensure you get the cheapest price possible for a flight from London to Ontario, you should look to book at least 56 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.

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 9 June 2026.
Read through reviews of airlines operating flights from London to Ontario, such as Virgin Atlantic,United Airlines, andBritish Airways. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Virgin Atlantic
7.5
Good
689 reviews
Check prices

Boarding

7.7

Entertainment

7.5

Comfort

7.3

Crew

8.1

Food

6.9

Overall

7.5

Reviews

1 / 20
10.0
Excellent

Edwin,May 2026

LHR - LAX

First time flying with Virgin. It was everything I hoped it would be.
Virgin Atlantic
7.5
Good
689 reviews
Virgin Atlantic
7.5
Good
689 reviews
Check prices

Boarding

7.7

Entertainment

7.5

Comfort

7.3

Crew

8.1

Food

6.9

Overall

7.5

Reviews

1 / 20
10.0
Excellent

Edwin,May 2026

LHR - LAX

First time flying with Virgin. It was everything I hoped it would be.
United Airlines
7.4
Good
9,800 reviews
Virgin Atlantic
7.5
Good
689 reviews
Check prices

Boarding

7.7

Entertainment

7.5

Comfort

7.3

Crew

8.1

Food

6.9

Overall

7.5

Reviews

1 / 20
10.0
Excellent

Edwin,May 2026

LHR - LAX

First time flying with Virgin. It was everything I hoped it would be.
British Airways
6.7
Okay
8,032 reviews
Virgin Atlantic
7.5
Good
689 reviews
Check prices

Boarding

7.7

Entertainment

7.5

Comfort

7.3

Crew

8.1

Food

6.9

Overall

7.5

Reviews

1 / 20
10.0
Excellent

Edwin,May 2026

LHR - LAX

First time flying with Virgin. It was everything I hoped it would be.

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 3 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, Virgin Atlantic, and Iberia fly from London to Ontario in about 17h 37m. The time it takes to get you to your destination can typically vary by up to 10h 32m. 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, United Airlines (£371), Virgin Atlantic (£375), and British Airways (£389) offers the cheapest pricing from London to Ontario. You may be able to fly from London to Ontario for 26% 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, March is the cheapest month in which you can book a flight from London to Ontario (average of £298). Flying from London to Ontario in May is currently the most expensive (average of £457). 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 3 airlines flying from London to Ontario

Discover the top 3 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 9 June 2026.
AirlineCheapestAverageFlexibilityOn-time
United AirlinesCheapest£371Average£477FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Virgin AtlanticCheapest£375Average£482FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
British AirwaysCheapest£389Average£491FlexibilityNo cancel feeOn-time70%
Search British Airways 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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