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$313+ Cheap flights from Ontario (ONT) to London (LON)

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 1/11. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LON
Aug 29 — Sep 51
Sat 8/29
Sat 9/5
1 adult, Economy
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Cheap 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 July 30, 2026.

This United Airlines deal was found by Cheapflights users on 7/29. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/96:37 pm
ONT
-
LHR
1 stop28h 48m
United Airlines
Thu 11/126:50 am
LHR
-
ONT
2 stops19h 57m
United Airlines
Deal found 7/29$736
This Priceline deal was found by Cheapflights users on 7/29. 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 11/1112:42 pm
ONT
-
LHR
1 stop13h 18m
Multiple Airlines
Mon 11/162:45 pm
LHR
-
ONT
1 stop16h 09m
Multiple Airlines
Deal found 7/29$800
This Priceline deal was found by Cheapflights users on 7/26. 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 11/312:42 pm
ONT
-
LHR
1 stop13h 18m
Multiple Airlines
Tue 11/172:45 pm
LHR
-
ONT
1 stop16h 09m
Multiple Airlines
Deal found 7/26$801
This Priceline deal was found by Cheapflights users on 7/28. 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.
Mon 10/266:02 am
ONT
-
LHR
1 stop23h 18m
Alaska Airlines
Sat 10/312:45 pm
LHR
-
ONT
1 stop28h 33m
Alaska Airlines
Deal found 7/28$806
This Priceline deal was found by Cheapflights users on 7/27. 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 11/2410:30 am
ONT
-
LHR
1 stop13h 45m
Multiple Airlines
Tue 12/12:45 pm
LHR
-
ONT
1 stop32h 02m
Multiple Airlines
Deal found 7/27$807
This Orbitz deal was found by Cheapflights users on 7/25. 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 Orbitz is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/74:09 pm
ONT
-
LHR
1 stop36h 11m
Alaska Airlines
Sun 12/62:45 pm
LHR
-
ONT
1 stop15h 54m
Alaska Airlines
Deal found 7/25$812
This Expedia deal was found by Cheapflights users on 7/29. 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 9/1510:39 pm
ONT
-
LHR
1 stop14h 06m
Multiple Airlines
Tue 9/228:55 am
LHR
-
ONT
1 stop17h 58m
Multiple Airlines
Deal found 7/29$815
This Expedia deal was found by Cheapflights users on 7/27. 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 11/2410:30 am
ONT
-
LHR
1 stop13h 45m
British Airways
Tue 12/11:50 pm
LHR
-
ONT
1 stop15h 49m
British Airways
Deal found 7/27$816
This Expedia deal was found by Cheapflights users on 7/25. 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.
Sun 11/16:00 am
ONT
-
LHR
1 stop20h 00m
Multiple Airlines
Mon 11/303:45 pm
LHR
-
ONT
2 stops26h 06m
Multiple Airlines
Deal found 7/25$822
This Expedia deal was found by Cheapflights users on 7/26. 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 11/247:00 am
ONT
-
LHR
1 stop17h 15m
Multiple Airlines
Sun 11/2910:20 am
LHR
-
ONT
2 stops55h 31m
Multiple Airlines
Deal found 7/26$823
This Priceline deal was found by Cheapflights users on 7/29. 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.
Sun 11/86:00 am
ONT
-
LHR
1 stop22h 20m
Multiple Airlines
Mon 11/231:50 pm
LHR
-
ONT
1 stop15h 49m
Multiple Airlines
Deal found 7/29$824
This Delta deal was found by Cheapflights users on 7/28. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/261:24 pm
ONT
-
LGW
2 stops19h 21m
Delta
Fri 11/610:00 am
LGW
-
ONT
2 stops20h 43m
Delta
Deal found 7/28$876

Find 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 July 30, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$736
(United Airlines)

One-way from

$313
(Flightnetwork)

Popular in

July

Cheapest in

June

Average price

$1,253
Provider with most accurate pricing for Ontario-London (LON) flight deals.
Search Deals
Provider most trusted by Cheapflights users for Ontario-London (LON) flights.
Search Deals
From Ontario to London (LON)
Search Deals
One-way flight from Ontario to London (LON)
Search Deals
Highest demand for flights based on searches. 13% potential increase in price ($127 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 5% potential price decrease ($40 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in July 2026
Search Deals

Cheapflights Fare Finder

 
Customize 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 2,558,603 searches. Data last updated July 30, 2026.
Use the filters below to find and compare flights from Ontario to London that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 9/9

10:39 pm-8:45 pm

1 stop14h 06m

London Heathrow

Wed 9/16

8:15 am-8:57 pm

1 stop20h 42m

$894

OntarioLondon

ONT - LGW

ONTLGW

Ontario

Tue 12/29

10:59 pm-3:45 pm

2 stops32h 46m

London Gatwick

Fri 1/8

10:00 am-10:43 pm

2 stops20h 43m

$906

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 9/14

3:14 pm-3:05 pm

1 stop15h 51m

London Heathrow

Fri 10/16

5:00 pm-11:42 pm

1 stop14h 42m

$951

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 9/14

3:14 pm-3:05 pm

1 stop15h 51m

London Heathrow

Thu 10/15

5:00 pm-11:42 pm

1 stop14h 42m

$951

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 10/3

1:52 pm-7:25 am

1 stop33h 33m

London Heathrow

Sun 10/11

2:50 pm-8:58 pm

1 stop14h 08m

$989
Quickest round-trip

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 8/31

1:18 pm-12:25 pm

1 stop15h 07m

London Heathrow

Wed 9/16

2:50 pm-8:53 pm

1 stop14h 03m

$990

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 9/13

10:39 pm-8:45 pm

1 stop14h 06m

London Heathrow

Sun 9/20

11:55 am-8:27 pm

1 stop16h 32m

$1,004

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 8/25

7:00 am-6:45 am

1 stop15h 45m

London Heathrow

Mon 9/7

8:00 am-8:53 pm

2 stops20h 53m

$1,010

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 8/31

1:18 pm-12:25 pm

1 stop15h 07m

London Heathrow

Mon 9/14

2:50 pm-8:53 pm

1 stop14h 03m

$1,036

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 9/9

10:39 pm-8:45 pm

1 stop14h 06m

London Heathrow

Wed 9/23

8:15 am-8:57 pm

1 stop20h 42m

$1,045

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/28

Showing 1-10 of 60 resultsSorted by cheapest first
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6

Compare providers for flights from Ontario to London

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 London in July.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 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 flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Ontario-London flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Ontario-London flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Ontario-London 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 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 London

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

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

Currently, March is the cheapest month in which you can book a flight from Ontario to London (average of $652). Flying from Ontario to London in July is currently the most expensive (average of $1,326). 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?

Airfare is below average for this route at the moment.
Ontario to London flights typically cost between $823 and $1,085 in November.
The cheapest round-trip price found within the last 5 days was $736 on United Airlines (Nov 9-Nov 12).

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 July 30, 2026.
Get a feel of what it's like to fly with Delta,Virgin Atlantic, andUnited Airlines from Ontario to London by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
7.8
Good
8,497 reviews

Comfort

7.8

Entertainment

7.8

Boarding

8.1

Crew

8.5

Overall

7.8

Food

7.2

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
7.8
Good
8,497 reviews
Delta
7.8
Good
8,497 reviews

Comfort

7.8

Entertainment

7.8

Boarding

8.1

Crew

8.5

Overall

7.8

Food

7.2

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
7.5
Good
694 reviews
Delta
7.8
Good
8,497 reviews

Comfort

7.8

Entertainment

7.8

Boarding

8.1

Crew

8.5

Overall

7.8

Food

7.2

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
10,048 reviews
Delta
7.8
Good
8,497 reviews

Comfort

7.8

Entertainment

7.8

Boarding

8.1

Crew

8.5

Overall

7.8

Food

7.2

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.
British Airways
6.7
Okay
8,128 reviews
Delta
7.8
Good
8,497 reviews

Comfort

7.8

Entertainment

7.8

Boarding

8.1

Crew

8.5

Overall

7.8

Food

7.2

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?

    Most people fly from Ontario (ONT) if they book a flight from Ontario to London. On average, Ontario has 0 outbound flights to London per day from 6 airlines. Ontario is conveniently located just 3.1 mi from Ontario’s city center.

  • How long is the flight from Ontario to London?

    JetBlue, Delta, and Alaska Airlines can get you from Ontario to London in just under 14h 06m. Your travel time can differ by up to 18h 40m. Airlines will cover a distance of 5407 mi. This flight may include one or multiple stops.

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

    Flying on British Airways is currently your cheapest option to London, with prices starting at $329. Additional round-trip tickets that might be worth considering are offered by Virgin Atlantic and Delta, with the lowest prices starting at $469 and $535, respectively. You may be able to fly from Ontario to London for 59% less than the average price by searching for these airlines.

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

    The most popular flight routes from Ontario to London are Ontario - London Heathrow, Ontario - London Gatwick and Ontario - London City.

  • 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 vacation 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, March is the cheapest month in which you can book a flight from Ontario to London (average of $652). Flying from Ontario to London in July is currently the most expensive (average of $1,326). 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?

Book flights to London if you plan to visit one of these locations
Ilford
Dorking
Hounslow
Winchester
Croydon
Gatwick
Wembley
Harrow
Eastleigh
Southend-on-Sea
Watford
Dartford
Chipping Norton
Kingston upon Thames
Eastbourne
Slough
Stansted
Sutton
Luton
Harlow

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Top 6 airlines flying from Ontario to London

Discover the top 6 airlines that operate flights from Ontario to London. 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 July 30, 2026.
AirlineCheapestAverageFlexibilityOn-time
British AirwaysCheapest$329Average$756FlexibilityNo cancel feeOn-time70%
Virgin AtlanticCheapest$469Average$646FlexibilityNo cancel feeOn-time72%
DeltaCheapest$535Average$788FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$620Average$650FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$665Average$1,256FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$931Average$1,592FlexibilityNo cancel feeOn-time75%

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