Find flights
When to book
Airlines
FAQs

Cheap flights from London to Ontario from £337

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 16/3. Fares are subject to change and may not be available on all flights or dates of travel.
LON — ONT
9 Apr — 16 Apr1
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 10 March 2026.

Mon 30/310:35
LHR
-
ONT
1 stop15h 12m
United Airlines
Sat 25/407:00
ONT
-
LHR
1 stop17h 30m
United Airlines
Deal found 9/3£365
Wed 22/410:05
LHR
-
ONT
1 stop14h 17m
British Airways
Thu 30/410:59
ONT
-
LHR
1 stop13h 06m
British Airways
Deal found 5/3£380
Fri 17/410:05
LHR
-
ONT
1 stop14h 17m
British Airways
Thu 23/410:59
ONT
-
LHR
1 stop13h 06m
British Airways
Deal found 5/3£397
Thu 19/306:30
LHR
-
ONT
2 stops18h 11m
United Airlines
Sun 22/323:59
ONT
-
LHR
1 stop22h 56m
United Airlines
Deal found 5/3£403
Mon 20/407:25
LHR
-
ONT
2 stops18h 22m
United Airlines
Mon 27/406:00
ONT
-
LHR
1 stop17h 25m
United Airlines
Deal found 6/3£405
Fri 17/414:50
LHR
-
ONT
1 stop13h 46m
United Airlines
Sat 2/513:40
ONT
-
LHR
1 stop14h 40m
United Airlines
Deal found 5/3£409
Tue 17/310:15
LHR
-
ONT
1 stop15h 27m
British Airways
Wed 29/410:59
ONT
-
LHR
1 stop12h 56m
British Airways
Deal found 5/3£413
Wed 15/410:50
LHR
-
ONT
2 stops19h 55m
United Airlines
Wed 29/418:49
ONT
-
LHR
1 stop28h 36m
United Airlines
Deal found 7/3£415
Mon 27/409:30
LHR
-
ONT
2 stops20h 20m
United Airlines
Sat 9/510:43
ONT
-
LHR
1 stop16h 27m
United Airlines
Deal found 5/3£415
Wed 22/410:50
LHR
-
ONT
2 stops19h 55m
United Airlines
Wed 29/406:05
ONT
-
LHR
2 stops17h 10m
United Airlines
Deal found 8/3£416
Thu 23/409:30
LHR
-
ONT
2 stops20h 20m
United Airlines
Thu 30/407:00
ONT
-
LHR
2 stops19h 40m
United Airlines
Deal found 9/3£417
Fri 17/411:30
LGW
-
ONT
2 stops20h 16m
Iberia
Fri 24/414:08
ONT
-
LGW
2 stops21h 52m
Iberia
Deal found 5/3£481

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 10 March 2026.

Round-trip from

£365

One-way from

£337

Popular in

July

Cheapest in

September

Average price

£421
United Airlines
  • United Airlines
  • 30/3-25/4
  • 2 total stops
  • 32h 42m total
  • London to Ontario
Search Deals
16/3
  • 16/3
  • 2 total stops
  • 29h 38m total
  • London to Ontario
Search Deals
Highest demand for flights based on searches. 5% potential increase in price (£21 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease (£10 potential savings vs. average return price).
Search Deals
Average for round-trip flights in March 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 10 March 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

Fri 24/4

16:15-22:45

1 stop14h 30m

Ontario

Mon 27/4

13:27-11:10

1 stop13h 43m

£409

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Fri 17/4

14:50-20:36

1 stop13h 46m

Ontario

Sat 2/5

13:40-12:20

1 stop14h 40m

£438
Fastest return journey

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Sat 18/4

14:50-20:36

1 stop13h 46m

Ontario

Sat 25/4

13:27-11:10

1 stop13h 43m

£438

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Thu 16/4

16:15-22:45

1 stop14h 30m

Ontario

Tue 5/5

13:30-11:10

1 stop13h 40m

£438

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Fri 4/9

16:15-22:58

1 stop14h 43m

Ontario

Sat 19/9

13:18-12:20

1 stop15h 02m

£439

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Thu 14/5

14:10-22:35

1 stop16h 25m

Ontario

Mon 18/5

13:30-11:10

1 stop13h 40m

£439

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Fri 1/5

14:50-20:36

1 stop13h 46m

Ontario

Tue 5/5

18:59-21:35

2 stops18h 36m

£439

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Mon 6/4

07:25-17:47

2 stops18h 22m

Ontario

Mon 13/4

18:49-20:40

2 stops17h 51m

£439

LondonOntario

LGW - ONT

LGWONT

London Gatwick

Fri 17/4

11:30-23:46

2 stops20h 16m

Ontario

Fri 24/4

14:08-20:00

2 stops21h 52m

£481

LondonOntario

LGW - ONT

LGWONT

London Gatwick

Tue 7/4

10:35-22:34

2 stops19h 59m

Ontario

Tue 14/4

14:20-16:00

2 stops17h 40m

£505

Flights are sorted by cheapest return flights first.

Deals found on 6/3

Showing 1-10 of 60 resultsSorted by cheapest first
1
2
3
...
6

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 March 2026.

To ensure you get the cheapest price possible for a flight from London to Ontario, you should look to book at least 76 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 £240). Flying from London to Ontario in July is currently the most expensive (average of £388). 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 £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 52m.

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 23m.

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

Boarding

7.7

Comfort

7.3

Crew

8.2

Overall

7.5

Entertainment

7.6

Food

6.9

Reviews

1 / 20
10.0
Excellent

Jorge,Jun 2025

SFO - LHR

Exceptional, the flight attendant were amazing. My economy delight seat was very comfortable, and I was fortunate enough to have an empty row
Virgin Atlantic
7.5
Good
680 reviews
Virgin Atlantic
7.5
Good
680 reviews
Check prices

Boarding

7.7

Comfort

7.3

Crew

8.2

Overall

7.5

Entertainment

7.6

Food

6.9

Reviews

1 / 20
10.0
Excellent

Jorge,Jun 2025

SFO - LHR

Exceptional, the flight attendant were amazing. My economy delight seat was very comfortable, and I was fortunate enough to have an empty row
United Airlines
7.4
Good
9,410 reviews
Virgin Atlantic
7.5
Good
680 reviews
Check prices

Boarding

7.7

Comfort

7.3

Crew

8.2

Overall

7.5

Entertainment

7.6

Food

6.9

Reviews

1 / 20
10.0
Excellent

Jorge,Jun 2025

SFO - LHR

Exceptional, the flight attendant were amazing. My economy delight seat was very comfortable, and I was fortunate enough to have an empty row
Lufthansa
6.8
Okay
7,841 reviews
Virgin Atlantic
7.5
Good
680 reviews
Check prices

Boarding

7.7

Comfort

7.3

Crew

8.2

Overall

7.5

Entertainment

7.6

Food

6.9

Reviews

1 / 20
10.0
Excellent

Jorge,Jun 2025

SFO - LHR

Exceptional, the flight attendant were amazing. My economy delight seat was very comfortable, and I was fortunate enough to have an empty row
British Airways
6.7
Okay
7,781 reviews
Virgin Atlantic
7.5
Good
680 reviews
Check prices

Boarding

7.7

Comfort

7.3

Crew

8.2

Overall

7.5

Entertainment

7.6

Food

6.9

Reviews

1 / 20
10.0
Excellent

Jorge,Jun 2025

SFO - LHR

Exceptional, the flight attendant were amazing. My economy delight seat was very comfortable, and I was fortunate enough to have an empty row

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 5 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, Iberia, and Delta fly from London to Ontario in about 14h 30m. The time it takes to get you to your destination can typically vary by up to 5h 46m. 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 (£377), and British Airways (£382) 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, September is the cheapest month in which you can book a flight from London to Ontario (average of £240). Flying from London to Ontario in July is currently the most expensive (average of £388). 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

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for London to Ontario

See prices for flight routes from nearby airports that may be better suited for you.
Heathrow to Los Angeles flights
Heathrow to Las Vegas flights
Heathrow to San Francisco flights
Stansted to Los Angeles flights
Gatwick to Los Angeles flights
London City to Los Angeles flights
Heathrow to Ontario flights
Gatwick to Las Vegas flights
Gatwick to San Francisco flights
Stansted to San Francisco flights
Luton to Los Angeles flights
London City to Las Vegas flights
London City to San Francisco flights
Heathrow to San Diego flights
Stansted to Las Vegas flights
Heathrow to Long Beach flights
Heathrow to Santa Ana flights
Manchester to Las Vegas flights
Heathrow to San Jose flights
Luton to San Francisco flights
Manchester to Los Angeles flights
Luton to Las Vegas flights
Gatwick to San Diego flights
London City to San Diego flights
Manchester to San Francisco flights
Stansted to San Diego flights
Birmingham to Las Vegas flights
Edinburgh to Los Angeles flights
Manchester to Ontario flights
Edinburgh to Las Vegas flights
Heathrow to Oakland flights
Gatwick to San Jose flights
Edinburgh to San Francisco flights
Edinburgh to San Diego flights
Heathrow to Burbank flights
Birmingham to Los Angeles flights
Manchester to Santa Ana flights
Manchester to Long Beach flights
Heathrow to Sacramento flights
Gatwick to Sacramento flights
London City to Santa Ana flights
Leeds to Los Angeles flights
Gatwick to Oakland flights
Birmingham to San Francisco flights
Newcastle upon Tyne to Las Vegas flights
Newcastle upon Tyne to Los Angeles flights
Southampton to Los Angeles flights
Gatwick to Ontario flights
Manchester to San Diego flights
London City to Sacramento flights

Top 5 airlines flying from London to Ontario

Discover the top 5 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 10 March 2026.
AirlineCheapestAverageFlexibilityOn-time
United AirlinesCheapest£371Average£467FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
Virgin AtlanticCheapest£377Average£506FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
British AirwaysCheapest£382Average£468FlexibilityNo cancel feeOn-time70%
Search British Airways flights
KLMCheapest£469Average£618FlexibilityNo cancel feeOn-time75%
Search KLM flights
LufthansaCheapest£482Average£775FlexibilityNo 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.

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.