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Cheap flights from London to Ontario from £304

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 7/5. Fares are subject to change and may not be available on all flights or dates of travel.
LON — ONT
29 Mar — 5 Apr1
1 adult

Cheapflights Tip: The best prices from London to Ontario are usually found in February or January, booked 77 days in advance, depart on a Wednesday or Tuesday and return on a Monday

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 24 March 2025.

Round-trip from

£402

One-way from

£304

Popular in

August

Cheapest in

February

Average price

£499
Virgin Atlantic
  • Virgin Atlantic
  • 6/5-17/5
  • 4 total stops
  • 79h 37m total
  • London to Ontario
7/5
  • 7/5
  • 3 total stops
  • 44h 57m total
  • London to Ontario
Highest demand for flights based on searches. 17% potential increase in price (£89 potential increase over avg. return price).
Cheapest flight prices on average. 5% potential price decrease (£22 potential savings vs. average return price).
Average for round-trip flights in March 2025

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 24 March 2025.

Tue 6/514:45LHR - ONT
2 stops40h 57mVirgin Atlantic
Sat 17/511:46ONT - LHR
1 stop15h 34mVirgin Atlantic
Deal found 23/3£402
Tue 22/415:10LHR - ONT
1 stop15h 00mBritish Airways
Tue 29/416:35ONT - LHR
1 stop12h 15mBritish Airways
Deal found 23/3£409
Tue 22/410:55LHR - ONT
1 stop13h 38mKLM
Tue 29/412:07ONT - LHR
1 stop15h 03mKLM
Deal found 23/3£420
Fri 12/915:40LHR - ONT
1 stop14h 00mAmerican Airlines
Mon 22/915:00ONT - LHR
1 stop13h 30mAmerican Airlines
Deal found 24/3£423
Wed 7/509:55LHR - ONT
2 stops20h 40mDelta
Mon 19/514:55ONT - LHR
1 stop15h 20mDelta
Deal found 23/3£426
Wed 7/509:30LHR - ONT
2 stops19h 23mUnited Airlines
Wed 14/505:05ONT - LHR
2 stops17h 40mUnited Airlines
Deal found 23/3£459
Wed 23/412:20LGW - ONT
2 stops19h 30mMultiple Airlines
Wed 14/522:40ONT - LGW
2 stops25h 30mMultiple Airlines
Deal found 24/3£485
Tue 1/415:10LHR - ONT
1 stop15h 17mFinnair
Wed 30/410:54ONT - LHR
1 stop14h 06mFinnair
Deal found 24/3£491
Thu 1/508:30LHR - ONT
2 stops38h 39mAir Canada
Thu 15/505:05ONT - LHR
2 stops46h 45mAir Canada
Deal found 23/3£492
Wed 7/509:20LCY - ONT
2 stops21h 15mDelta
Wed 14/513:10ONT - LCY
2 stops19h 30mDelta
Deal found 23/3£503
Mon 31/316:25LHR - ONT
1 stop15h 29mAlaska Airlines
Mon 7/414:44ONT - LHR
1 stop14h 01mAlaska Airlines
Deal found 24/3£519
Sun 20/415:10LHR - ONT
1 stop15h 00mIberia
Sun 27/414:44ONT - LHR
1 stop34h 16mIberia
Deal found 24/3£521

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 24 March 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

Tue 6/5

17:10-23:42

2 stops38h 32m

Ontario

Sat 17/5

13:10-14:15

2 stops41h 05m

£402

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Tue 22/4

15:10-22:10

1 stop15h 00m

Ontario

Tue 29/4

16:35-12:50

1 stop12h 15m

£409

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Tue 22/4

10:55-16:33

1 stop13h 38m

Ontario

Tue 29/4

12:07-11:10

1 stop15h 03m

£420

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Wed 7/5

09:55-22:35

2 stops20h 40m

Ontario

Wed 14/5

14:55-14:15

1 stop15h 20m

£426

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Sat 19/4

10:30-18:29

1 stop15h 59m

Ontario

Fri 2/5

14:44-12:45

1 stop14h 01m

£448

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Wed 7/5

09:30-20:53

2 stops19h 23m

Ontario

Wed 14/5

05:05-06:45

2 stops17h 40m

£459

LondonOntario

LGW - ONT

LGWONT

London Gatwick

Wed 23/4

12:20-23:50

2 stops19h 30m

Ontario

Wed 14/5

22:40-08:10

2 stops25h 30m

£485

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Tue 1/4

15:10-22:27

1 stop15h 17m

Ontario

Wed 30/4

10:54-09:00

1 stop14h 06m

£491

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Thu 1/5

08:30-15:09

2 stops38h 39m

Ontario

Thu 15/5

05:05-11:50

2 stops46h 45m

£492

LondonOntario

LCY - ONT

LCYONT

London City

Wed 7/5

09:20-22:35

2 stops21h 15m

Ontario

Wed 14/5

13:10-16:40

2 stops19h 30m

£503

Flights are sorted by cheapest return flights first.

Deals found on 23/3

Showing 1-10 of 44 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 21 March 2025.

To ensure you get the cheapest price possible for a flight from London to Ontario, you should look to book at least 77 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, March is the cheapest month in which you can book a flight from London to Ontario (average of £516). Flying from London to Ontario in August is currently the most expensive (average of £827). 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 24 March 2025.

It’s optimal to fly from London to Ontario in the evening. By choosing this option you can save up to 15% on the cost of your flight, compared to a flight at midday.

Rainfall in Ontario by month

Plan your trip to Ontario by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Ontario ranges from 3.0 - 86.0 inches per month. February is typically the wettest month, when rainfall can reach 86.0 mm. June is typically the driest time to visit Ontario when rainfall is around 3.0 mm.

Temperature in Ontario by month

Plan your trip to Ontario by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Ontario, use this chart to help with planning. For those seeking warmer temperatures, August is the ideal time of year to visit, when temperatures reach an average of 26.0 C. Travellers hoping to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 12.0 C).

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 24 March 2025.
Read reviews from past customers who have flown Delta, Alaska Airlines and KLM from London to Ontario. In addition to providing an overall rating, users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.

Boarding

8.2

Comfort

8.0

Food

7.3

Crew

8.5

Entertainment

7.9

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception
8.0
Very Good

Boarding

8.2

Comfort

8.0

Food

7.3

Crew

8.5

Entertainment

7.9

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

Boarding

8.2

Comfort

8.0

Food

7.3

Crew

8.5

Entertainment

7.9

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

Boarding

8.2

Comfort

8.0

Food

7.3

Crew

8.5

Entertainment

7.9

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

Boarding

8.2

Comfort

8.0

Food

7.3

Crew

8.5

Entertainment

7.9

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

Boarding

8.2

Comfort

8.0

Food

7.3

Crew

8.5

Entertainment

7.9

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

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.

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

    According to our current data, Virgin Atlantic (£402), British Airways (£409), and KLM (£420) offers the cheapest pricing from London to Ontario. You may be able to fly from London to Ontario for 29% less than the average price by searching for these airlines.

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

    To fly one-way, consider booking your trip with Lufthansa, which is currently one of the cheapest options available, starting at £389. Iberia flights start at £410 while deals on WestJet start at £455 one-way.

  • What are the most popular routes 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 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 £516). Flying from London to Ontario in August is currently the most expensive (average of £827). 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

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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.

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 24 March 2025.
AirlineCheapestAverageFlexibilityOn-time
KLMCheapest£393Average£602FlexibilityNo cancel feeOn-time75%
Search KLM flights
Virgin AtlanticCheapest£423Average£526FlexibilityNo cancel feeOn-time72%
Search Virgin Atlantic flights
FinnairCheapest£424Average£507FlexibilityNo cancel feeOn-time76%
Search Finnair flights
British AirwaysCheapest£426Average£591FlexibilityNo cancel feeOn-time70%
Search British Airways flights
United AirlinesCheapest£442Average£613FlexibilityNo cancel feeOn-time69%
Search United Airlines flights
LufthansaCheapest£457Average£553FlexibilityNo 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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