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Cheap flights from London to Ontario from £323

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 4/3. Fares are subject to change and may not be available on all flights or dates of travel.
LON — ONT
15 Feb — 22 Feb1
1 adult
1 adult, Economy, 0 bags

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 16 January 2026.

Round-trip from

£347

One-way from

£323

Popular in

July

Cheapest in

January

Average price

£407
United Airlines
  • United Airlines
  • 12/2-23/2
  • 4 total stops
  • 42h 32m total
  • London to Ontario
Search Deals
United Airlines
  • United Airlines
  • 4/3
  • 2 total stops
  • 20h 27m total
  • London to Ontario
Search Deals
Highest demand for flights based on searches. 17% potential increase in price (£83 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease (£18 potential savings vs. average return price).
Search Deals
Average for round-trip flights in January 2026
Search Deals

Find 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 16 January 2026.

Thu 12/209:30
LHR
-
ONT
2 stops21h 27m
United Airlines
Mon 23/206:00
ONT
-
LHR
1 stop20h 15m
United Airlines
Deal found 15/1£347
Tue 10/207:30
LHR
-
ONT
2 stops23h 23m
United Airlines
Tue 17/206:10
ONT
-
LHR
2 stops18h 15m
United Airlines
Deal found 13/1£348
Fri 27/209:30
LHR
-
ONT
2 stops18h 37m
United Airlines
Fri 6/323:59
ONT
-
LHR
2 stops22h 31m
United Airlines
Deal found 13/1£353
Tue 12/507:25
LHR
-
ONT
2 stops18h 22m
United Airlines
Sat 16/518:54
ONT
-
LHR
2 stops33h 26m
United Airlines
Deal found 15/1£358
Mon 27/409:30
LHR
-
ONT
2 stops20h 20m
United Airlines
Sat 9/505:05
ONT
-
LHR
1 stop23h 15m
United Airlines
Deal found 13/1£359
Sat 28/215:05
LHR
-
ONT
1 stop15h 32m
Virgin Atlantic
Sat 7/313:10
ONT
-
LHR
1 stop12h 50m
Virgin Atlantic
Deal found 14/1£360
Sat 28/208:30
LHR
-
ONT
2 stops21h 29m
United Airlines
Sat 7/313:40
ONT
-
LHR
1 stop14h 20m
United Airlines
Deal found 14/1£362
Sat 31/110:45
LHR
-
ONT
1 stop19h 03m
Virgin Atlantic
Wed 18/213:10
ONT
-
LHR
1 stop12h 50m
Virgin Atlantic
Deal found 13/1£363
Sat 31/110:45
LHR
-
ONT
1 stop19h 03m
Virgin Atlantic
Mon 16/207:30
ONT
-
LHR
1 stop19h 00m
Virgin Atlantic
Deal found 13/1£364
Sat 31/112:05
LHR
-
ONT
1 stop17h 53m
Multiple Airlines
Mon 16/205:00
ONT
-
LHR
2 stops18h 10m
Multiple Airlines
Deal found 13/1£368
Thu 19/210:05
LHR
-
ONT
1 stop15h 36m
United Airlines
Sun 22/213:50
ONT
-
LHR
1 stop14h 10m
United Airlines
Deal found 12/1£369
Thu 22/111:35
LHR
-
ONT
1 stop17h 23m
United Airlines
Wed 4/213:24
ONT
-
LHR
1 stop12h 16m
United Airlines
Deal found 14/1£370

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 16 January 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

Sun 1/3

11:30-22:57

2 stops19h 27m

Ontario

Sun 8/3

06:15-07:25

1 stop18h 10m

£347

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Thu 12/2

09:30-22:57

2 stops21h 27m

Ontario

Mon 23/2

06:00-10:15

1 stop20h 15m

£347

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Wed 4/3

06:30-22:57

2 stops24h 27m

Ontario

Wed 18/3

13:40-12:00

1 stop15h 20m

£348

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Thu 5/2

10:05-17:43

1 stop15h 38m

Ontario

Mon 16/2

13:50-12:00

1 stop14h 10m

£369

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Fri 20/2

10:05-17:41

1 stop15h 36m

Ontario

Sun 22/2

13:50-12:00

1 stop14h 10m

£370

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Sat 21/2

10:05-17:41

1 stop15h 36m

Ontario

Tue 10/3

13:50-09:40

1 stop12h 50m

£370

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Sun 8/2

10:05-17:43

1 stop15h 38m

Ontario

Sun 15/2

13:50-12:00

1 stop14h 10m

£370

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Thu 12/2

10:05-17:41

1 stop15h 36m

Ontario

Thu 5/3

13:40-12:00

1 stop14h 20m

£370

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Sat 14/2

10:05-17:41

1 stop15h 36m

Ontario

Fri 20/2

13:50-12:00

1 stop14h 10m

£371

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Sun 1/3

11:35-20:50

1 stop17h 15m

Ontario

Sun 15/3

06:15-12:00

1 stop22h 45m

£371

Flights are sorted by cheapest return flights first.

Deals found on 15/1

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 9 January 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 £239). Flying from London to Ontario in July is currently the most expensive (average of £396). 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 30% 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 £393.

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 49m.

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 Denver (DEN) offer the fastest connection on this route, with an average stopover time of 1h 19m.

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 16 January 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
1,349 reviews
Check prices

Comfort

7.4

Overall

7.6

Food

6.7

Boarding

7.7

Entertainment

6.9

Crew

8.2

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2025

FRA - DFW

I was lucky I had a seet without no one next to me My vegetarian meal was excellent. The service very good. Although there was a lot of turbulences during the flight, the landing was very soft and took away all our apprehension.
Finnair
7.6
Good
1,349 reviews
Finnair
7.6
Good
1,349 reviews
Check prices

Comfort

7.4

Overall

7.6

Food

6.7

Boarding

7.7

Entertainment

6.9

Crew

8.2

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2025

FRA - DFW

I was lucky I had a seet without no one next to me My vegetarian meal was excellent. The service very good. Although there was a lot of turbulences during the flight, the landing was very soft and took away all our apprehension.
Virgin Atlantic
7.5
Good
678 reviews
Finnair
7.6
Good
1,349 reviews
Check prices

Comfort

7.4

Overall

7.6

Food

6.7

Boarding

7.7

Entertainment

6.9

Crew

8.2

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2025

FRA - DFW

I was lucky I had a seet without no one next to me My vegetarian meal was excellent. The service very good. Although there was a lot of turbulences during the flight, the landing was very soft and took away all our apprehension.
United Airlines
7.4
Good
9,163 reviews
Finnair
7.6
Good
1,349 reviews
Check prices

Comfort

7.4

Overall

7.6

Food

6.7

Boarding

7.7

Entertainment

6.9

Crew

8.2

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2025

FRA - DFW

I was lucky I had a seet without no one next to me My vegetarian meal was excellent. The service very good. Although there was a lot of turbulences during the flight, the landing was very soft and took away all our apprehension.
Lufthansa
6.8
Okay
7,718 reviews
Finnair
7.6
Good
1,349 reviews
Check prices

Comfort

7.4

Overall

7.6

Food

6.7

Boarding

7.7

Entertainment

6.9

Crew

8.2

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2025

FRA - DFW

I was lucky I had a seet without no one next to me My vegetarian meal was excellent. The service very good. Although there was a lot of turbulences during the flight, the landing was very soft and took away all our apprehension.
British Airways
6.7
Okay
7,680 reviews
Finnair
7.6
Good
1,349 reviews
Check prices

Comfort

7.4

Overall

7.6

Food

6.7

Boarding

7.7

Entertainment

6.9

Crew

8.2

Reviews

1 / 20
10.0
Excellent

Anonymous,May 2025

FRA - DFW

I was lucky I had a seet without no one next to me My vegetarian meal was excellent. The service very good. Although there was a lot of turbulences during the flight, the landing was very soft and took away all our apprehension.

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 19h 27m. 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 (£280), United Airlines (£370), and Virgin Atlantic (£375) 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 £239). Flying from London to Ontario in July is currently the most expensive (average of £396). 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 16 January 2026.
AirlineCheapestAverageFlexibilityOn-time
FinnairCheapest£280Average£438FlexibilityNo cancel feeOn-time76%
Search Finnair flights
United AirlinesCheapest£370Average£523FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Virgin AtlanticCheapest£375Average£501FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
British AirwaysCheapest£386Average£469FlexibilityNo cancel feeOn-time70%
Search British Airways flights
KLMCheapest£395Average£616FlexibilityNo cancel feeOn-time75%
Search KLM flights
LufthansaCheapest£424Average£580FlexibilityNo 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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