Find flights
When to book
FAQs

Cheap flights from Ontario to London Heathrow Airport from £206

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 5/12. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LHR
15 Oct — 22 Oct1
1 adult
1 adult, Economy

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 15 September 2025.

Round-trip from

£428

One-way from

£206

Popular in

June

Cheapest in

October

Average price

£512
Iberia
  • Iberia
  • 14/1-19/1
  • 3 total stops
  • 38h 00m total
  • Ontario to London
Search Deals
5/12
  • 5/12
  • 3 total stops
  • 30h 51m total
  • Ontario to London
Search Deals
Highest demand for flights based on searches. 22% potential increase in price (£131 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 5% potential price decrease (£23 potential savings vs. average return price).
Search Deals
Average for round-trip flights in September 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 15 September 2025.

Tue 23/916:45ONT - LHR
1 stop13h 55mBritish Airways
Tue 7/1008:20LHR - ONT
1 stop16h 08mBritish Airways
Deal found 14/9£436
Wed 24/909:55ONT - LHR
1 stop15h 55mDelta
Wed 1/1009:00LHR - ONT
2 stops21h 23mDelta
Deal found 14/9£438
Mon 27/1012:48ONT - LHR
1 stop12h 47mMultiple Airlines
Fri 7/1115:00LHR - ONT
1 stop15h 29mMultiple Airlines
Deal found 13/9£444
Mon 1/1213:20ONT - LHR
2 stops15h 30mVirgin Atlantic
Tue 9/1211:40LHR - ONT
2 stops20h 19mVirgin Atlantic
Deal found 14/9£447
Sat 4/1011:55ONT - LHR
1 stop35h 20mDelta
Fri 17/1018:00LHR - ONT
1 stop25h 08mDelta
Deal found 14/9£448
Wed 1/1011:55ONT - LHR
2 stops17h 55mDelta
Thu 30/1006:20LHR - ONT
2 stops17h 50mDelta
Deal found 14/9£462
Wed 1/1008:15ONT - LHR
1 stop16h 45mIberia
Wed 8/1012:00LHR - ONT
1 stop18h 42mIberia
Deal found 14/9£462
Sun 21/910:55ONT - LHR
1 stop14h 05mBritish Airways
Sat 4/1008:20LHR - ONT
1 stop22h 13mBritish Airways
Deal found 14/9£473
Tue 23/912:47ONT - LHR
1 stop17h 38mIberia
Tue 7/1006:10LHR - ONT
2 stops24h 32mIberia
Deal found 14/9£475
Fri 17/1016:49ONT - LHR
1 stop12h 01mBritish Airways
Tue 28/1008:20LHR - ONT
1 stop15h 08mBritish Airways
Deal found 14/9£476

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 15 September 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

Wed 29/10

07:05-09:00

1 stop18h 55m

London Heathrow

Wed 5/11

06:20-22:22

2 stops24h 02m

£438

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 22/10

13:15-13:30

2 stops16h 15m

London Heathrow

Wed 29/10

06:20-21:20

2 stops22h 00m

£441

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 29/10

13:33-09:40

1 stop13h 07m

London Heathrow

Wed 5/11

13:30-22:51

2 stops17h 21m

£493

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 28/10

13:33-09:40

1 stop13h 07m

London Heathrow

Tue 4/11

10:05-17:34

1 stop15h 29m

£502

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 14/11

06:45-10:30

1 stop19h 45m

London Heathrow

Tue 18/11

08:55-19:37

1 stop18h 42m

£510

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 20/10

09:50-13:30

2 stops19h 40m

London Heathrow

Sun 26/10

10:45-23:39

1 stop19h 54m

£513

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 3/10

13:15-09:40

1 stop12h 25m

London Heathrow

Fri 17/10

11:25-17:23

1 stop13h 58m

£523

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 28/9

13:15-09:40

1 stop12h 25m

London Heathrow

Sun 5/10

11:25-17:23

1 stop13h 58m

£528

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 6/1

07:00-05:55

1 stop14h 55m

London Heathrow

Sun 11/1

10:05-17:43

1 stop15h 38m

£535

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 13/10

22:56-20:45

1 stop13h 49m

£276

Flights are sorted by cheapest return flights first.

Deals found on 14/9

Showing 1-10 of 20 results
1
2

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 12 September 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 62 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 15 September 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.

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.

  • How long is the flight from Ontario to London Heathrow Airport?

    Delta and United Airlines can get you from Ontario to London Heathrow Airport in just under 13h 07m. Your travel time can differ by up to 5h 48m. The distance between Ontario and London Heathrow Airport is about 5407 mi. This flight may include one or multiple stops.

  • 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 London Heathrow Airport?

Book flights to London Heathrow Airport if you plan to visit one of these locations
Milton Keynes
Croydon
Hounslow
Gatwick
Slough
Northampton
Luton
Deal
Wembley
Ilford
Crawley
Hayes
Watford
Folkestone
Winchester
Chichester
Ipswich
Swindon
Dartford
Eastbourne

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Ontario to Heathrow

See prices for flight routes from nearby airports that may be better suited for you.
Los Angeles to Heathrow flights
San Francisco to Heathrow flights
Los Angeles to London City flights
Los Angeles to Gatwick flights
San Francisco to Gatwick flights
San Francisco to London City flights
San Diego to Heathrow flights
Los Angeles to Stansted flights
Los Angeles to Luton flights
Santa Ana to Heathrow flights
San Francisco to Stansted flights
San Francisco to Luton flights
Las Vegas to Heathrow flights
San Diego to Gatwick flights
San Jose to Heathrow flights
Burbank to Heathrow flights
Oakland to Heathrow flights
Sacramento to Heathrow flights
Las Vegas to Gatwick flights
Las Vegas to London City flights
San Jose to Gatwick flights
Oakland to Gatwick flights
Sacramento to Gatwick flights
Santa Ana to Gatwick flights
Ontario to Gatwick flights
Palm Springs to Heathrow flights
Reno to Heathrow flights
San Diego to Stansted flights
Los Angeles to Southend flights
Las Vegas to Luton flights
Reno to Gatwick flights
Burbank to Gatwick flights
Medford to Heathrow flights
Santa Barbara to Heathrow 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 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!

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.