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Cheap flights from Ontario to London from £213

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 24/9. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LON
18 Jun — 25 Jun1
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 13 June 2025.

Round-trip from

£385

One-way from

£213

Popular in

June

Cheapest in

September

Average price

£789
Delta
  • Delta
  • 15/10-11/11
  • 3 total stops
  • 34h 48m total
  • Ontario to London
24/9
  • 24/9
  • 2 total stops
  • 31h 16m total
  • Ontario to London
Highest demand for flights based on searches. 6% potential increase in price (£28 potential increase over avg. return price).
Cheapest flight prices on average. 3% potential price decrease (£15 potential savings vs. average return price).
Average for round-trip flights in June 2025

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 13 June 2025.

Wed 15/1011:29ONT - LHR
1 stop15h 51mDelta
Tue 11/1106:20LHR - ONT
2 stops18h 57mDelta
Deal found 13/6£385
Tue 21/1013:00ONT - LHR
1 stop12h 50mKLM
Wed 29/1009:20LHR - ONT
1 stop17h 22mKLM
Deal found 12/6£391
Tue 9/1217:09ONT - LHR
1 stop12h 11mBritish Airways
Tue 16/1214:55LHR - ONT
1 stop15h 03mBritish Airways
Deal found 12/6£467
Sun 19/1015:00ONT - LGW
2 stops21h 00mIberia
Wed 29/1011:00LGW - ONT
2 stops31h 35mIberia
Deal found 12/6£477
Sun 3/813:34ONT - LHR
1 stop14h 46mUnited Airlines
Tue 19/814:50LHR - ONT
1 stop13h 53mUnited Airlines
Deal found 12/6£478
Sun 5/1014:30ONT - LHR
1 stop15h 55mIberia
Tue 14/1006:10LHR - ONT
2 stops25h 52mIberia
Deal found 11/6£484
Sun 27/711:40ONT - LHR
1 stop17h 50mMultiple Airlines
Sun 3/813:25LHR - ONT
1 stop17h 22mMultiple Airlines
Deal found 12/6£489
Sun 3/816:45ONT - LHR
1 stop12h 05mAmerican Airlines
Tue 19/811:15LHR - ONT
1 stop14h 37mAmerican Airlines
Deal found 11/6£495
Thu 17/711:40ONT - LHR
1 stop17h 50mVirgin Atlantic
Thu 24/709:40LHR - ONT
2 stops22h 02mVirgin Atlantic
Deal found 11/6£496
Sun 5/1022:56ONT - LHR
1 stop13h 49mJetBlue
Fri 10/1008:15LHR - ONT
1 stop21h 14mJetBlue
Deal found 12/6£553
Sat 6/905:10ONT - LHR
2 stops17h 20mAir Canada
Sat 13/914:05LHR - ONT
2 stops59h 24mAir Canada
Deal found 11/6£568
Thu 4/907:05ONT - LCY
2 stops16h 10mDelta
Thu 18/909:20LCY - ONT
2 stops21h 21mDelta
Deal found 12/6£592

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 13 June 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 15/10

11:29-11:20

1 stop15h 51m

London Heathrow

Tue 11/11

06:20-17:17

2 stops18h 57m

£385

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 21/10

13:00-09:50

1 stop12h 50m

London Heathrow

Wed 29/10

09:20-19:42

1 stop17h 22m

£391

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 9/12

17:09-13:20

1 stop12h 11m

London Heathrow

Tue 16/12

14:55-21:58

1 stop15h 03m

£467

OntarioLondon

ONT - LGW

ONTLGW

Ontario

Sun 19/10

15:00-20:00

2 stops21h 00m

London Gatwick

Wed 29/10

11:00-11:35

2 stops31h 35m

£477

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 3/8

13:34-12:20

1 stop14h 46m

London Heathrow

Tue 19/8

14:50-20:43

1 stop13h 53m

£478

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 5/10

14:30-14:25

1 stop15h 55m

London Heathrow

Tue 14/10

06:10-00:02

2 stops25h 52m

£484

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 27/7

11:40-13:30

1 stop17h 50m

London Heathrow

Sun 3/8

13:25-22:47

1 stop17h 22m

£489

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 3/8

16:45-12:50

1 stop12h 05m

London Heathrow

Tue 19/8

11:15-17:52

1 stop14h 37m

£495

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Thu 17/7

11:40-13:30

1 stop17h 50m

London Heathrow

Thu 24/7

09:40-23:42

2 stops22h 02m

£496

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 5/10

22:56-20:45

1 stop13h 49m

London Heathrow

Fri 10/10

08:15-21:29

1 stop21h 14m

£553

Flights are sorted by cheapest return flights first.

Deals found on 11/6

Showing 1-10 of 41 results
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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 9 June 2025.

Booking 78 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 13 June 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 19% 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 13 June 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.

Entertainment

7.9

Crew

8.5

Overall

8.0

Comfort

7.9

Boarding

8.2

Food

7.3

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.
8.0
Very Good

Entertainment

7.9

Crew

8.5

Overall

8.0

Comfort

7.9

Boarding

8.2

Food

7.3

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.

Entertainment

7.9

Crew

8.5

Overall

8.0

Comfort

7.9

Boarding

8.2

Food

7.3

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.

Entertainment

7.9

Crew

8.5

Overall

8.0

Comfort

7.9

Boarding

8.2

Food

7.3

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.

Entertainment

7.9

Crew

8.5

Overall

8.0

Comfort

7.9

Boarding

8.2

Food

7.3

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.

Entertainment

7.9

Crew

8.5

Overall

8.0

Comfort

7.9

Boarding

8.2

Food

7.3

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 £385, was found to be the cheapest airline from Ontario to London.Alternate airlines flying return to your destination include KLM and British Airways. Users have found that Delta is 32% cheaper than the other options available to this destination.

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

    £290 is the cheapest one-way deal found within the past few days, from JetBlue. You may also be able to find cheap deals on United Airlines and Air Canada, with prices starting from £294 and £295, respectively.

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

  • 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
Croydon
Milton Keynes
Gatwick
Luton
Slough
Wembley
Crawley
Eastbourne
Ilford
Southend-on-Sea
Watford
Hayes
Ipswich
Winchester
Folkestone
Maidstone
Dartford
Guildford

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