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 £387. Other airlines that can offer you cheap pricing are Virgin Atlantic, from £414, and KLM, from £423. Delta is currently priced 37% 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 £265. Users have also found prices from £277 and £283 on Virgin Atlantic and British Airways, respectively.

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.

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).

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

To save up to 51% on this flight, we recommend booking at least 56 days prior to travel. The price may fluctuate and will likely increase closer to your departure date. Users on Cheapflights have found tickets from Ontario to London Heathrow Airport from £530 1-2 weeks out and tickets from £725 for flights departing within the next 72 hours.

What is the cheapest month to fly from Ontario to London Heathrow Airport?

October can be a great time to fly to London Heathrow Airport from Ontario with a flight ticket averaging about £537. Cheapflights users have found deals in the month of October for as cheap as £325. The most expensive prices can be found in the month of December.

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.

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.

£257+ Flights from Ontario to London Heathrow Airport

Cheap flight deals from Ontario to Heathrow

Round-trip from	£387
One-way from	£257
Popular in	June
Cheapest in	March
Average price	£759

Delta
3/8-19/8
2 total stops
32h 45m total
Ontario to London

Search Deals

5/8
2 total stops
26h 56m total
Ontario to London

Search Deals

Highest demand for flights based on searches. 23% potential increase in price (£142 potential increase over avg. return price).

Search Deals

Cheapest flight prices on average. 5% potential price decrease (£24 potential savings vs. average return price).

Search Deals

Average for round-trip flights in July 2025

Search Deals

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 12 July 2025.

Tue 19/813:15ONT - LHR

1 stop12h 35mVirgin Atlantic

Thu 4/910:55LHR - ONT

1 stop19h 45mVirgin Atlantic

Deal found 11/7£369

Tue 26/811:40ONT - LHR

1 stop18h 35mDelta

Tue 9/911:30LHR - ONT

2 stops19h 12mDelta

Deal found 11/7£387

Tue 26/809:50ONT - LHR

1 stop16h 00mKLM

Tue 9/909:20LHR - ONT

1 stop17h 51mKLM

Deal found 10/7£394

Wed 8/1013:00ONT - LHR

1 stop12h 50mMultiple Airlines

Tue 21/1010:55LHR - ONT

1 stop13h 19mMultiple Airlines

Deal found 9/7£475

Wed 27/805:10ONT - LHR

1 stop20h 30mUnited Airlines

Fri 17/1016:00LHR - ONT

2 stops28h 51mUnited Airlines

Deal found 9/7£478

Tue 2/913:15ONT - LHR

2 stops38h 35mAir Canada

Wed 10/915:50LHR - ONT

2 stops28h 42mAir Canada

Deal found 9/7£486

Mon 18/808:14ONT - LHR

1 stop14h 11mIberia

Fri 5/908:20LHR - ONT

1 stop18h 34mIberia

Deal found 9/7£488

Best flights from Ontario to Heathrow
Discover carefully curated flight deals from Ontario to Heathrow that have cost, travel time, and stopovers in mind to ensure you get the best travel experience. Data last updated 12 July 2025.

Sun 3/811:40ONT - LHR

1 stop15h 30mDelta

Tue 19/813:05LHR - ONT

1 stop17h 15mDelta

Deal found 11/7£387

Sun 24/807:05ONT - LHR

1 stop15h 40mVirgin Atlantic

Sun 31/810:55LHR - ONT

1 stop19h 45mVirgin Atlantic

Deal found 10/7£414

Mon 15/913:15ONT - LHR

1 stop12h 35mKLM

Fri 26/913:05LHR - ONT

1 stop17h 18mKLM

Deal found 10/7£423

Wed 8/1013:00ONT - LHR

1 stop12h 50mMultiple Airlines

Tue 21/1010:55LHR - ONT

1 stop13h 19mMultiple Airlines

Deal found 9/7£475

Wed 27/805:10ONT - LHR

1 stop20h 30mUnited Airlines

Fri 17/1016:00LHR - ONT

2 stops28h 51mUnited Airlines

Deal found 9/7£478

Tue 2/913:15ONT - LHR

2 stops38h 35mAir Canada

Fri 12/917:40LHR - ONT

2 stops26h 52mAir Canada

Deal found 9/7£486

Mon 18/810:50ONT - LHR

1 stop14h 10mIberia

Thu 4/910:30LHR - ONT

1 stop20h 03mIberia

Deal found 9/7£488

Last-minute flights from Ontario to Heathrow
Discover last-minute flight deals from Ontario to Heathrow. Data last updated 12 July 2025 and is based on user searches.

Wed 16/707:00ONT - LHR

1 stop15h 20mUnited Airlines

Wed 23/714:50LHR - ONT

1 stop14h 04mUnited Airlines

Deal found 9/7£575

Wed 16/716:45ONT - LHR

1 stop12h 05mBritish Airways

Mon 21/715:40LHR - ONT

1 stop13h 58mBritish Airways

Deal found 10/7£783

Thu 17/711:25ONT - LHR

1 stop15h 55mDelta

Mon 21/706:30LHR - ONT

2 stops25h 12mDelta

Deal found 10/7£535

Thu 17/705:05ONT - LHR

2 stops20h 55mAir Canada

Mon 21/715:50LHR - ONT

2 stops57h 35mAir Canada

Deal found 10/7£634

Thu 17/700:59ONT - LHR

1 stop24h 01mMultiple Airlines

Sat 26/715:40LHR - ONT

1 stop25h 43mMultiple Airlines

Deal found 10/7£1,216

Fri 18/713:15ONT - LHR

1 stop12h 35mKLM

Wed 23/711:00LHR - ONT

1 stop13h 29mKLM

Deal found 10/7£496

Sat 19/723:59ONT - LHR

1 stop25h 31mJetBlue

Sat 9/811:55LHR - ONT

1 stop18h 15mJetBlue

Deal found 11/7£658

Sun 20/714:37ONT - LHR

1 stop14h 08mIberia

Thu 7/816:25LHR - ONT

1 stop15h 43mIberia

Deal found 11/7£545

Sun 3/800:59ONT - LHR

1 stop21h 26mBritish Airways

Mon 11/819:30LHR - ONT

2 stops30h 54mBritish Airways

Deal found 10/7£540

Mon 18/808:14ONT - LHR

1 stop14h 11mIberia

Fri 5/908:20LHR - ONT

1 stop18h 34mIberia

Deal found 9/7£488

Tue 19/813:15ONT - LHR

1 stop12h 35mVirgin Atlantic

Thu 4/910:55LHR - ONT

1 stop19h 45mVirgin Atlantic

Deal found 11/7£369

Tue 26/811:40ONT - LHR

1 stop18h 35mDelta

Tue 9/911:30LHR - ONT

2 stops19h 12mDelta

Deal found 11/7£387

One-way flights from Ontario to Heathrow
Search for one-way flight options from Ontario to Heathrow. Find affordable one-way fares based on user searches. Data last updated 12 July 2025.

Tue 5/800:59ONT - LHR

2 stops26h 56mMultiple Airlines

Deal found 9/7£257

Sat 26/723:59ONT - LHR

1 stop25h 31mJetBlue

Deal found 11/7£265

Mon 24/1113:00ONT - LHR

1 stop13h 00mVirgin Atlantic

Deal found 10/7£277

Wed 15/1016:49ONT - LHR

1 stop12h 01mBritish Airways

Deal found 10/7£283

Mon 11/813:15ONT - LHR

1 stop12h 35mKLM

Deal found 11/7£294

Tue 29/713:19ONT - LHR

1 stop13h 06mUnited Airlines

Deal found 11/7£298

Mon 8/906:00ONT - LHR

2 stops20h 00mAir Canada

Deal found 10/7£303

Fri 1/810:53ONT - LHR

2 stops25h 47mIberia

Deal found 11/7£345

Thu 24/722:05ONT - LHR

2 stops24h 20mDelta

Deal found 11/7£347

Sat 19/718:53ONT - LHR

1 stop33h 57mAmerican Airlines

Deal found 10/7£393

Cheapflights Fare Finder

Use the filters below to find and compare flights from Ontario to London Heathrow Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 3/8

11:40-11:10

1 stop15h 30m

London Heathrow

Tue 19/8

13:05-22:20

1 stop17h 15m

£387

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 24/8

07:05-06:45

1 stop15h 40m

London Heathrow

Sun 31/8

10:55-22:40

1 stop19h 45m

£414

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 15/9

13:15-09:50

1 stop12h 35m

London Heathrow

Fri 26/9

13:05-22:23

1 stop17h 18m

£423

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 8/10

13:00-09:50

1 stop12h 50m

London Heathrow

Tue 21/10

10:55-16:14

1 stop13h 19m

£475

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 27/8

05:10-09:40

1 stop20h 30m

London Heathrow

Fri 17/10

16:00-12:51

2 stops28h 51m

£478

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 2/9

13:15-11:50

2 stops38h 35m

London Heathrow

Wed 10/9

15:50-12:32

2 stops28h 42m

£486

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 18/8

08:14-06:25

1 stop14h 11m

London Heathrow

Fri 5/9

08:20-18:54

1 stop18h 34m

£488

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 5/8

00:59-11:55

2 stops26h 56m

£257

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 26/7

23:59-09:30

1 stop25h 31m

£265

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 24/11

13:00-10:00

1 stop13h 00m

£277

Flights are sorted by cheapest return flights first.

Deals found on 9/7

Showing 1-10 of 17 results

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?

To ensure you get the cheapest price possible for a flight from Ontario to London Heathrow Airport, you should look to book at least 72 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?

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.

Reviews of airlines servicing Heathrow

Check out reviews from past customers who have flown with Delta, KLM, andUnited Airlines from Ontario to London Heathrow Airport to help guide your decision. 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

7,950 reviews

Check prices

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

7,950 reviews

Delta

8.0

Very Good

7,950 reviews

Check prices

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

1,372 reviews

Delta

8.0

Very Good

7,950 reviews

Check prices

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

8,849 reviews

Delta

8.0

Very Good

7,950 reviews

Check prices

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

654 reviews

Delta

8.0

Very Good

7,950 reviews

Check prices

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

2,914 reviews

Delta

8.0

Very Good

7,950 reviews

Check prices

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

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 £387. Other airlines that can offer you cheap pricing are Virgin Atlantic, from £414, and KLM, from £423. Delta is currently priced 37% 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 £265. Users have also found prices from £277 and £283 on Virgin Atlantic and British Airways, 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

Hounslow

Croydon

Milton Keynes

Deal

Northampton

Gatwick

Slough

Luton

Wembley

Crawley

Eastbourne

Ilford

Hayes

Ipswich

Folkestone

Southend-on-Sea

Watford

Winchester

Swindon

Maidstone

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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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Cheap flights from Ontario to London Heathrow Airport from £257

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 5/8. Fares are subject to change and may not be available on all flights or dates of travel.

Cheap flight deals from Ontario to Heathrow

Round-trip from

One-way from

Popular in

Cheapest in

Average price

Find flight deals from Ontario to Heathrow

Cheapest flights from Ontario to HeathrowExplore 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 12 July 2025.

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 12 July 2025.

Cheapflights Fare Finder

Use the filters below to find and compare flights from Ontario to London Heathrow Airport that are best for you.

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.

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 27 June 2025.

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

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 12 July 2025.

Reviews of airlines servicing Heathrow

Check out reviews from past customers who have flown with Delta, KLM, andUnited Airlines from Ontario to London Heathrow Airport to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.

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?

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

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

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

How can I find direct flights from Ontario to Heathrow?

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

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

Travelling to a place near Ontario?

Browse thousands of different options on Cheapflights for your next trip

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Alternative routes for Ontario to Heathrow

See prices for flight routes from nearby airports that may be better suited for you.

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 Ontario to Heathrow?

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

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

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

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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 12 July 2025.