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Cheap flights from Ontario to London from £286

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 23/7. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LON
5 May — 12 May1
1 adult

Cheap flight deals from Ontario to London

Discover tips and strategies to find the most affordable flight options for your journey from Ontario (ONT) to London (LON). 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 30 April 2025.

Round-trip from

£506

One-way from

£286

Popular in

June

Cheapest in

October

Average price

£557
Delta
  • Delta
  • 13/8-30/8
  • 3 total stops
  • 41h 58m total
  • Ontario to London
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Iberia
  • Iberia
  • 23/7
  • 1 total stop
  • 14h 04m total
  • Ontario to London
Search Deals
Highest demand for flights based on searches. 12% potential increase in price (£59 potential increase over avg. return price).
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Cheapest flight prices on average. 4% potential price decrease (£17 potential savings vs. average return price).
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Average for round-trip flights in April 2025
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Find flight deals from Ontario to London

Cheapest flights from Ontario to London
Explore the most affordable flight options available from Ontario to London. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 30 April 2025.

Wed 13/812:00ONT - LHR
1 stop17h 30mDelta
Sat 30/806:15LHR - ONT
2 stops24h 28mDelta
Deal found 29/4£506
Wed 10/905:10ONT - LHR
2 stops17h 20mAir Canada
Fri 19/914:05LHR - ONT
2 stops30h 27mAir Canada
Deal found 29/4£518
Tue 13/516:15ONT - LHR
1 stop12h 05mUnited Airlines
Tue 20/509:30LHR - ONT
2 stops19h 04mUnited Airlines
Deal found 29/4£526
Wed 5/1107:00ONT - LHR
2 stops15h 30mMultiple Airlines
Wed 12/1113:00LHR - ONT
2 stops17h 35mMultiple Airlines
Deal found 29/4£540
Sun 21/923:00ONT - LHR
1 stop13h 45mJetBlue
Tue 21/1011:55LHR - ONT
1 stop17h 46mJetBlue
Deal found 29/4£559
Fri 14/1111:00ONT - LHR
1 stop13h 15mIberia
Sat 22/1114:55LHR - ONT
1 stop15h 05mIberia
Deal found 30/4£576
Fri 1/816:45ONT - LHR
1 stop12h 05mBritish Airways
Sun 31/815:40LHR - ONT
1 stop13h 59mBritish Airways
Deal found 29/4£585
Tue 6/522:59ONT - LHR
1 stop13h 46mIcelandair
Tue 13/508:15LHR - ONT
1 stop20h 56mIcelandair
Deal found 29/4£587
Wed 23/716:45ONT - LHR
1 stop12h 05mAmerican Airlines
Thu 7/815:40LHR - ONT
1 stop13h 59mAmerican Airlines
Deal found 29/4£682
Tue 13/513:10ONT - LHR
1 stop12h 40mKLM
Wed 21/511:00LHR - ONT
1 stop13h 17mKLM
Deal found 29/4£685
Tue 10/607:05ONT - LGW
2 stops18h 55mDelta
Tue 17/612:00LGW - ONT
2 stops18h 25mDelta
Deal found 29/4£759
Tue 10/607:00ONT - LCY
2 stops21h 30mMultiple Airlines
Tue 17/609:25LCY - ONT
2 stops21h 20mMultiple Airlines
Deal found 29/4£843

Cheapflights Fare Finder

Customise your flight search to find flights from Ontario to London 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 30 April 2025.
Use the filters below to find and compare flights from Ontario to London that are best for you.

Fly from

Ontario

Fly to

London

Route

Depart

Return

Price

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 13/8

12:00-13:30

1 stop17h 30m

London Heathrow

Sat 30/8

06:15-22:43

2 stops24h 28m

£506

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 10/9

05:10-06:30

2 stops17h 20m

London Heathrow

Fri 19/9

14:05-12:32

2 stops30h 27m

£518

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 13/5

16:15-12:20

1 stop12h 05m

London Heathrow

Tue 20/5

09:30-20:34

2 stops19h 04m

£526

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 21/9

23:00-20:45

1 stop13h 45m

London Heathrow

Tue 21/10

11:55-21:41

1 stop17h 46m

£559

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 1/8

16:45-12:50

1 stop12h 05m

London Heathrow

Sun 31/8

15:40-21:39

1 stop13h 59m

£585

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Thu 24/7

12:46-10:50

1 stop14h 04m

London Heathrow

Mon 18/8

15:10-23:29

1 stop16h 19m

£621

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 23/7

16:45-12:50

1 stop12h 05m

London Heathrow

Thu 7/8

15:40-21:39

1 stop13h 59m

£682

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 13/5

13:10-09:50

1 stop12h 40m

London Heathrow

Wed 21/5

11:00-16:17

1 stop13h 17m

£685

OntarioLondon

ONT - LGW

ONTLGW

Ontario

Tue 10/6

07:05-10:00

2 stops18h 55m

London Gatwick

Tue 17/6

12:00-22:25

2 stops18h 25m

£759

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 10/5

05:05-06:30

2 stops17h 25m

London Heathrow

Sat 17/5

15:50-12:38

2 stops28h 48m

£799

Flights are sorted by cheapest return flights first.

Deals found on 30/4

Showing 1-10 of 34 results
1
2
3
4

Best time to book a flight from Ontario to London

Have a flexible travel schedule? Discover the best time to fly to London from Ontario 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 Ontario to London

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

Use this chart to determine the optimal time to book a return flight from Ontario to London. Price data was last updated on 25 April 2025.

Booking 20 days in advance of your planned departure date is, on average, the best time to get cheap flights from Ontario to London. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

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

Currently, January is the cheapest month in which you can book a flight from Ontario to London (average of £112). Flying from Ontario to London in August is currently the most expensive (average of £164). 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 ONT to LON?

Find hourly flight availability from Ontario to London. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 30 April 2025.

One of the essential ways to save on airfare from Ontario to London is to remain as flexible as possible. Flights that are in the morning tend to be the most expensive. A flight at midday could potentially save you up to 18% on airfare.

Rainfall in London by month

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

In terms of precipitation, rainfall in London ranges from 40.0 - 70.0 inches per month. January is typically the wettest month, when rainfall can reach 70.0 mm. July is typically the driest time to visit London when rainfall is around 40.0 mm.

Temperature in London by month

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

If weather is an important factor for your trip to London, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 17.0 C. Travellers hoping to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 4.0 C).

Reviews of airlines servicing London

Get insights into the airlines that provide service to London. 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 London. Reviews last updated 30 April 2025.
Get a feel of what it's like to fly with Delta, KLM and United Airlines from Ontario to London by reading reviews from past customers. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
8.0
Very Good
7,934 reviews
Check prices

Entertainment

7.9

Comfort

7.9

Crew

8.5

Food

7.3

Boarding

8.2

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
Delta
8.0
Very Good
7,934 reviews
Delta
8.0
Very Good
7,934 reviews
Check prices

Entertainment

7.9

Comfort

7.9

Crew

8.5

Food

7.3

Boarding

8.2

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
KLM
7.8
Good
1,334 reviews
Delta
8.0
Very Good
7,934 reviews
Check prices

Entertainment

7.9

Comfort

7.9

Crew

8.5

Food

7.3

Boarding

8.2

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
United Airlines
7.4
Good
8,696 reviews
Delta
8.0
Very Good
7,934 reviews
Check prices

Entertainment

7.9

Comfort

7.9

Crew

8.5

Food

7.3

Boarding

8.2

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
Virgin Atlantic
7.4
Good
643 reviews
Delta
8.0
Very Good
7,934 reviews
Check prices

Entertainment

7.9

Comfort

7.9

Crew

8.5

Food

7.3

Boarding

8.2

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
JetBlue
7.3
Good
2,922 reviews
Delta
8.0
Very Good
7,934 reviews
Check prices

Entertainment

7.9

Comfort

7.9

Crew

8.5

Food

7.3

Boarding

8.2

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

Related info for your journey

Find useful and relevant information for your journey from Ontario to London. 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 from for flights from Ontario to London?

    Ontario (ONT), located 3.1 mi from the city center, is the airport you fly out of when you book flights from Ontario to London. 0 airlines have flights from Ontario to London on a regular basis. Booking flights from Ontario to London should not be difficult; the airport handles an average of 0 outbound flights to London per day.

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

    Delta, at £506, was found to be the cheapest airline from Ontario to London.Alternate airlines flying return to your destination include Air Canada and United Airlines. Users have found that Delta is 12% cheaper than the other options available to this destination.

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

    £286 is the cheapest one-way deal found within the past few days, from Iberia. You may also be able to find cheap deals on JetBlue and Virgin Atlantic, with prices starting from £294 and £295, respectively.

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

    When deciding which route to take from Ontario to London consider Ontario - London Heathrow, Ontario - London Gatwick or Ontario - London City as they are the most popular.

  • Can I find deals for flights from Ontario to London that include hotel bookings?

    Yes. In addition to deals on Ontario to London flights, Cheapflights offers holiday packages that include both flights and hotel.

  • How can I find direct flights from Ontario to London?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Ontario to London.

  • Can I find deals for business class flights from Ontario to London?

    Yes. Cheapflights offers flight deals from Ontario to London 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 Ontario to London?

    Currently, January is the cheapest month in which you can book a flight from Ontario to London (average of £112). Flying from Ontario to London in August is currently the most expensive (average of £164). 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

Travelling to a place near Ontario?

Book flights to Ontario if you plan to visit one of these locations
Deal
Hounslow
Milton Keynes
Gatwick
Luton
Slough
Croydon
Eastbourne
Southend-on-Sea
Ilford
Crawley
Hayes
Ipswich
Watford
Wembley
Folkestone
Maidstone
Winchester
Dartford
Guildford

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Fly with Cheapflights

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How does Cheapflights help users find flights from Ontario to London?

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

Cheapflights taps into our reliable network of hundreds of airlines and travel agencies to find the best deals for flights from Ontario to London for you. Better yet — we are completely free to use.

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

Yes! Cheapflights helps users easily find flights from Ontario to London with no change fees.

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

Yes! Start tracking prices for Ontario to London flights today and get alerted whenever prices for these flights change. To access this feature, click the bell icon next to the flight deals above, which will prompt you for a valid email address to receive your alerts.

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