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Heathrow

$293+ Cheap flights from Ontario (ONT) to Heathrow (LHR)

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 7/29. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LHR
Jul 21 — Jul 281
Tue 7/21
Tue 7/28
1 adult, Economy
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Cheap 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 June 21, 2026.

This Expedia deal was found by Cheapflights users on 6/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/1710:47 am
ONT
-
LHR
1 stop17h 13m
Multiple Airlines
Tue 12/152:45 pm
LHR
-
ONT
1 stop17h 10m
Multiple Airlines
Deal found 6/19$826
This lastminute.com deal was found by Cheapflights users on 6/19. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure lastminute.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/41:05 pm
ONT
-
LHR
1 stop13h 25m
British Airways
Sat 10/3110:15 am
LHR
-
ONT
1 stop15h 42m
British Airways
Deal found 6/19$827
This Priceline deal was found by Cheapflights users on 6/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 11/106:00 am
ONT
-
LHR
1 stop22h 20m
Multiple Airlines
Mon 12/72:45 pm
LHR
-
ONT
1 stop15h 34m
Multiple Airlines
Deal found 6/17$828
This Priceline deal was found by Cheapflights users on 6/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/1812:00 pm
ONT
-
LHR
1 stop16h 20m
Multiple Airlines
Mon 11/302:45 pm
LHR
-
ONT
1 stop15h 38m
Multiple Airlines
Deal found 6/20$838
This CheapOair deal was found by Cheapflights users on 6/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/165:00 am
ONT
-
LHR
2 stops17h 30m
Multiple Airlines
Tue 10/136:15 am
LHR
-
ONT
2 stops20h 42m
Multiple Airlines
Deal found 6/16$839
This Booking.com deal was found by Cheapflights users on 6/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/275:00 am
ONT
-
LHR
2 stops17h 30m
Multiple Airlines
Mon 10/195:00 pm
LHR
-
ONT
1 stop14h 45m
Multiple Airlines
Deal found 6/16$841
This Booking.com deal was found by Cheapflights users on 6/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/275:00 am
ONT
-
LHR
2 stops17h 30m
Multiple Airlines
Sat 10/175:00 pm
LHR
-
ONT
1 stop14h 45m
Multiple Airlines
Deal found 6/16$844
This Booking.com deal was found by Cheapflights users on 6/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/285:00 am
ONT
-
LHR
2 stops17h 35m
Multiple Airlines
Mon 10/195:00 pm
LHR
-
ONT
1 stop14h 45m
Multiple Airlines
Deal found 6/16$846
This Booking.com deal was found by Cheapflights users on 6/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/285:00 am
ONT
-
LHR
2 stops17h 35m
Multiple Airlines
Sat 10/175:00 pm
LHR
-
ONT
1 stop14h 45m
Multiple Airlines
Deal found 6/16$849

Find 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 June 21, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$826
(Expedia)

One-way from

$293
(Trip.com)

Popular in

June

Cheapest in

November

Average price

$1,592
Provider with most accurate pricing for Ontario-London Heathrow flight deals.
Search Deals
Provider most trusted by Cheapflights users for Ontario-London Heathrow flights.
Search Deals
From Ontario to London Heathrow
Search Deals
One-way flight from Ontario to London Heathrow
Search Deals
Highest demand for flights based on searches. 31% potential increase in price ($444 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 6% potential price decrease ($58 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in June 2026
Search Deals

Cheapflights Fare Finder

 
Customize 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 2,558,603 searches. Data last updated June 21, 2026.
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

Cheapest round-trip

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 11/9

12:00 pm-9:00 am

1 stop13h 00m

London Heathrow

Wed 11/18

10:45 am-4:12 pm

1 stop13h 27m

$895

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 8/26

1:18 pm-9:40 am

1 stop12h 22m

London Heathrow

Thu 9/3

1:00 pm-8:01 pm

1 stop15h 01m

$923

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 8/10

1:18 pm-9:40 am

1 stop12h 22m

London Heathrow

Mon 8/24

2:50 pm-8:53 pm

1 stop14h 03m

$963

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 7/15

1:00 pm-10:00 am

1 stop13h 00m

London Heathrow

Thu 9/10

10:55 am-4:35 pm

1 stop13h 40m

$975

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 7/14

1:00 pm-11:00 am

1 stop14h 00m

London Heathrow

Thu 9/10

10:55 am-4:35 pm

1 stop13h 40m

$975

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 8/5

1:18 pm-12:35 pm

1 stop15h 17m

London Heathrow

Wed 8/12

2:50 pm-8:53 pm

1 stop14h 03m

$996
Quickest round-trip

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 7/28

1:18 pm-9:40 am

1 stop12h 22m

London Heathrow

Wed 8/5

2:50 pm-8:42 pm

1 stop13h 52m

$1,066

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 8/7

1:18 pm-9:40 am

1 stop12h 22m

London Heathrow

Sun 8/23

2:50 pm-8:53 pm

1 stop14h 03m

$1,069

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 9/16

9:10 pm-8:45 pm

1 stop15h 35m

London Heathrow

Mon 9/21

8:15 am-8:13 pm

1 stop19h 58m

$1,093

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 9/5

11:24 pm-8:45 pm

1 stop13h 21m

London Heathrow

Sat 9/12

11:55 am-8:13 pm

1 stop16h 18m

$1,143

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/18

Showing 1-10 of 23 resultsSorted by cheapest first
1
2
3

Compare providers for flights from Ontario to Heathrow

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Ontario to Heathrow in June.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
CheapflightsfaresPrice Accuracy2 starsTrust Score*1 star
Thrive TravelPrice Accuracy3 starsTrust Score*2 stars
OvagoPrice Accuracy3 starsTrust Score*3 stars
AranGrantPrice Accuracy3 starsTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Ontario-London Heathrow Airport flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Ontario-London Heathrow Airport flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Ontario-London Heathrow Airport flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Ontario-London Heathrow Airport flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Ontario-London Heathrow Airport flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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 round-trip 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

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

Currently, November is the cheapest month in which you can book a flight from Ontario to London Heathrow Airport (average of $624). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of $1,592). 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.

How much does it cost to fly round-trip from Ontario to London Heathrow Airport?

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 June 21, 2026.
Read through reviews of airlines operating flights from Ontario to London Heathrow Airport, such as KLM,Delta, andUnited Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
KLM
7.8
Good
1,530 reviews

Boarding

7.8

Entertainment

7.2

Comfort

7.7

Food

7.3

Crew

8.4

Overall

7.8

Reviews

1 / 20
6.0
Good

Anonymous,Apr 2026

OKC - ATL

Flight was ok - difficult as I had seat next to bathroom.. Food awful
KLM
7.8
Good
1,530 reviews
KLM
7.8
Good
1,530 reviews

Boarding

7.8

Entertainment

7.2

Comfort

7.7

Food

7.3

Crew

8.4

Overall

7.8

Reviews

1 / 20
6.0
Good

Anonymous,Apr 2026

OKC - ATL

Flight was ok - difficult as I had seat next to bathroom.. Food awful
Delta
7.8
Good
8,424 reviews
KLM
7.8
Good
1,530 reviews

Boarding

7.8

Entertainment

7.2

Comfort

7.7

Food

7.3

Crew

8.4

Overall

7.8

Reviews

1 / 20
6.0
Good

Anonymous,Apr 2026

OKC - ATL

Flight was ok - difficult as I had seat next to bathroom.. Food awful
United Airlines
7.4
Good
9,870 reviews
KLM
7.8
Good
1,530 reviews

Boarding

7.8

Entertainment

7.2

Comfort

7.7

Food

7.3

Crew

8.4

Overall

7.8

Reviews

1 / 20
6.0
Good

Anonymous,Apr 2026

OKC - ATL

Flight was ok - difficult as I had seat next to bathroom.. Food awful
American Airlines
7.1
Good
11,727 reviews
KLM
7.8
Good
1,530 reviews

Boarding

7.8

Entertainment

7.2

Comfort

7.7

Food

7.3

Crew

8.4

Overall

7.8

Reviews

1 / 20
6.0
Good

Anonymous,Apr 2026

OKC - ATL

Flight was ok - difficult as I had seat next to bathroom.. Food awful
British Airways
6.7
Okay
8,062 reviews
KLM
7.8
Good
1,530 reviews

Boarding

7.8

Entertainment

7.2

Comfort

7.7

Food

7.3

Crew

8.4

Overall

7.8

Reviews

1 / 20
6.0
Good

Anonymous,Apr 2026

OKC - ATL

Flight was ok - difficult as I had seat next to bathroom.. Food awful

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?

    If you book a flight to London Heathrow from Ontario, you will be flying from Ontario, which is the city’s only airport. Ontario (ONT) is located 3.1 mi from the center of Ontario. There are 0 flights from Ontario to London Heathrow per day from 5 different airlines.

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

    United Airlines and KLM can get you from Ontario to London Heathrow Airport in just under 12h 22m. Your travel time can differ by up to 38m. The distance between Ontario and London Heathrow Airport is about 5407 mi. Both multi-stop and nonstop flights can be found to your destination and back.

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

    According to our current data, Delta ($570), KLM ($580), and American Airlines ($620) offers the cheapest pricing from Ontario to London Heathrow Airport. Delta is 40% cheaper than the average price of flights available within the next 90 days to this destination.

  • 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 vacation 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, November is the cheapest month in which you can book a flight from Ontario to London Heathrow Airport (average of $624). Flying from Ontario to London Heathrow Airport in June is currently the most expensive (average of $1,592). 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

Traveling to a place near London Heathrow Airport?

Book flights to London Heathrow Airport if you plan to visit one of these locations
Ilford
Dorking
Hounslow
Winchester
Croydon
Gatwick
Southend-on-Sea
Wembley
Harrow
Eastleigh
Dartford
Dover
Orpington
Watford
Northampton
Chipping Norton
Hayes
Kingston upon Thames
Eastbourne
Slough

Browse thousands of different options on Cheapflights for your next trip

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Top 5 airlines flying from Ontario to Heathrow

Discover the top 5 airlines that operate flights from Ontario to Heathrow. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated June 21, 2026.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$570Average$672FlexibilityNo cancel feeOn-timeN/A
KLMCheapest$580Average$672FlexibilityNo cancel feeOn-time75%
American AirlinesCheapest$620Average$650FlexibilityNo cancel feeOn-time71%
British AirwaysCheapest$624Average$856FlexibilityNo cancel feeOn-time70%
United AirlinesCheapest$665Average$1,025FlexibilityNo cancel feeOn-time69%

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