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Cheap flights from Ontario to London Heathrow Airport 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 3/5. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LHR
26 Mar — 2 Apr1
1 adult

Cheap flight deals from Ontario to Heathrow

Discover tips and strategies to find the most affordable flight options for your journey from Ontario (ONT) to Heathrow (LHR). 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 21 March 2025.

Round-trip from

£474

One-way from

£304

Popular in

June

Cheapest in

April

Average price

£511
Iberia
  • Iberia
  • 1/4-29/4
  • 3 total stops
  • 38h 03m total
  • Ontario to London
JetBlue
  • JetBlue
  • 3/5
  • 1 total stop
  • 14h 05m total
  • Ontario to London
Highest demand for flights based on searches. 19% potential increase in price (£111 potential increase over avg. return price).
Cheapest flight prices on average. 4% potential price decrease (£20 potential savings vs. average return price).
Average for round-trip flights in March 2025

Find flight deals from Ontario to Heathrow

Cheapest flights from Ontario to Heathrow
Explore the most affordable flight options available from Ontario to Heathrow. Find the lowest fares from popular airlines and budget airlines, with prices last updated on 21 March 2025.

Tue 8/410:54ONT - LHR
1 stop14h 06mIberia
Tue 22/412:00LHR - ONT
1 stop18h 10mIberia
Deal found 19/3£479
Tue 4/1117:01ONT - LHR
1 stop12h 19mBritish Airways
Tue 18/1110:40LHR - ONT
1 stop15h 09mBritish Airways
Deal found 20/3£484
Sun 6/407:00ONT - LHR
1 stop16h 15mVirgin Atlantic
Tue 22/413:25LHR - ONT
1 stop17h 18mVirgin Atlantic
Deal found 20/3£496
Mon 11/817:00ONT - LHR
1 stop11h 50mAmerican Airlines
Wed 27/811:15LHR - ONT
1 stop14h 33mAmerican Airlines
Deal found 20/3£516
Fri 2/518:48ONT - LHR
2 stops51h 42mUnited Airlines
Wed 14/507:30LHR - ONT
2 stops21h 04mUnited Airlines
Deal found 19/3£516
Sun 13/412:42ONT - LHR
1 stop14h 28mDelta
Thu 24/410:55LHR - ONT
1 stop13h 38mDelta
Deal found 21/3£523
Thu 1/514:35ONT - LHR
1 stop15h 40mKLM
Wed 7/511:00LHR - ONT
1 stop20h 42mKLM
Deal found 19/3£534
Fri 19/910:00ONT - LHR
2 stops17h 50mAir Canada
Mon 29/909:30LHR - ONT
2 stops21h 23mAir Canada
Deal found 19/3£579
Thu 11/1207:00ONT - LHR
2 stops15h 30mMultiple Airlines
Sat 31/111:10LHR - ONT
2 stops17h 07mMultiple Airlines
Deal found 20/3£591
Sat 3/522:40ONT - LHR
1 stop14h 05mJetBlue
Wed 14/508:15LHR - ONT
1 stop21h 07mJetBlue
Deal found 20/3£597
Wed 21/522:40ONT - LHR
1 stop14h 05mIcelandair
Wed 28/508:15LHR - ONT
1 stop21h 07mIcelandair
Deal found 20/3£731

Cheapflights Fare Finder

Customise your flight search to find flights from Ontario to Heathrow 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 21 March 2025.
Use the filters below to find and compare flights from Ontario to London Heathrow Airport that are best for you.

Fly from

Ontario

Fly to

Heathrow

Route

Depart

Return

Price

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 1/4

10:57-09:00

1 stop14h 03m

London Heathrow

Tue 29/4

06:10-22:10

2 stops24h 00m

£474

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 6/4

16:35-12:50

1 stop12h 15m

London Heathrow

Tue 22/4

15:40-21:58

1 stop14h 18m

£494

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 6/4

07:00-07:15

1 stop16h 15m

London Heathrow

Tue 22/4

13:25-22:43

1 stop17h 18m

£496

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 27/4

12:07-13:30

1 stop17h 23m

London Heathrow

Fri 9/5

11:20-22:29

1 stop19h 09m

£503

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 11/8

17:00-12:50

1 stop11h 50m

London Heathrow

Wed 27/8

11:15-17:48

1 stop14h 33m

£516

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 2/5

18:48-06:30

2 stops51h 42m

London Heathrow

Wed 14/5

07:30-20:34

2 stops21h 04m

£516

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Thu 1/5

14:35-14:15

1 stop15h 40m

London Heathrow

Wed 7/5

11:00-23:42

1 stop20h 42m

£534

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Thu 1/5

05:05-10:00

2 stops44h 55m

London Heathrow

Wed 7/5

14:05-12:38

2 stops30h 33m

£536

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 13/5

13:10-09:50

1 stop12h 40m

London Heathrow

Fri 7/11

11:00-17:22

1 stop14h 22m

£569

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 3/5

22:40-20:45

1 stop14h 05m

London Heathrow

Thu 8/5

08:15-21:22

1 stop21h 07m

£573

Flights are sorted by cheapest return flights first.

Deals found on 20/3

Showing 1-10 of 25 results
1
2
3

Best time to book a flight from Ontario to Heathrow

Have a flexible travel schedule? Discover the best time to fly to Heathrow 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 Heathrow Airport

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

Use this chart to determine the optimal time to book a return flight from Ontario to Heathrow. Price data was last updated on 14 March 2025.

To ensure you get the cheapest price possible for a flight from Ontario to London Heathrow Airport, you should look to book at least 49 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 Ontario to London Heathrow Airport?

Currently, January is the cheapest month in which you can book a flight from Ontario to London Heathrow Airport (average of £112). Flying from Ontario to London Heathrow Airport 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 LHR?

Find hourly flight availability from Ontario to Heathrow. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated 21 March 2025.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Ontario to London Heathrow Airport as you normally would.

Rainfall in Heathrow by month

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

In terms of precipitation, rainfall in London Heathrow Airport 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 Heathrow Airport when rainfall is around 40.0 mm.

Temperature in Heathrow by month

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

If weather is an important factor for your trip to London Heathrow Airport, 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 Heathrow

Get insights into the airlines that provide service to Heathrow. 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 Heathrow. Reviews last updated 21 March 2025.
Read reviews from past customers who have flown Delta, KLM and Air France from Ontario to London. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.

Overall

8.0

Boarding

8.2

Food

7.3

Comfort

8.0

Crew

8.5

Entertainment

7.9

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

Overall

8.0

Boarding

8.2

Food

7.3

Comfort

8.0

Crew

8.5

Entertainment

7.9

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.

Overall

8.0

Boarding

8.2

Food

7.3

Comfort

8.0

Crew

8.5

Entertainment

7.9

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.

Overall

8.0

Boarding

8.2

Food

7.3

Comfort

8.0

Crew

8.5

Entertainment

7.9

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.

Overall

8.0

Boarding

8.2

Food

7.3

Comfort

8.0

Crew

8.5

Entertainment

7.9

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.

Overall

8.0

Boarding

8.2

Food

7.3

Comfort

8.0

Crew

8.5

Entertainment

7.9

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 Heathrow. 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 Heathrow?

    Most people fly from Ontario (ONT) if they book a flight from Ontario to London Heathrow. On average, Ontario has 0 outbound flights to London Heathrow per day from 0 airlines. Ontario is conveniently located just 3.1 mi from Ontario’s city center.

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

    Cheapflights users have booked flights from Ontario to London Heathrow Airport round-trip from £474. Other airlines that can offer you cheap pricing are British Airways, from £494, and Virgin Atlantic, from £496. Iberia is currently priced 22% below the average price you’ll pay for this route.

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

    For one-way options, check prices for JetBlue. According to our data, you can fly for as low as £304. Users have also found prices from £320 and £324 on British Airways and KLM, respectively.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Ontario to Heathrow 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 Heathrow Airport?

    Currently, January is the cheapest month in which you can book a flight from Ontario to London Heathrow Airport (average of £112). Flying from Ontario to London Heathrow Airport 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
Hounslow
Deal
Milton Keynes
Gatwick
Croydon
Slough
Luton
Eastbourne
Northampton
Ilford
Swindon
Hayes
Crawley
Southend-on-Sea
Wembley
Maidstone
Winchester
Ipswich
Watford
Southall

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

When you search for this flight from Ontario to Heathrow, 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 Ontario to Heathrow?

It’s simple! Cheapflights, which is free to use for everyone, saves millions of users time and money every year by helping them find the cheapest and most suitable flights from Ontario to Heathrow.

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

Certainly. Search results for flights to Heathrow from Ontario shown to you on Cheapflights can be narrowed down with different useful search filters, which includes flexible booking options.

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

Yes, and it’s super simple to set up. Click the bell icon next to the flight deals above and provide a valid email address to enable Price Alerts. That’s it!

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