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$241+ 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 10/16. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LON
Oct 15 — Oct 221
Wed 10/15
Wed 10/22
1 adult, Economy
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Cheap 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 September 15, 2025.

Round-trip from

$581
(Iberia)

One-way from

$241
(Trip.com)

Popular in

December

Cheapest in

October

Average price

$684
From Ontario to London (LON)
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One-way flight from Ontario to London (LON)
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Highest demand for flights based on searches. 6% potential increase in price ($55 potential increase over avg. RT price).
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Cheapest flight prices on average. 4% potential price decrease ($33 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Find 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 September 15, 2025.

This oojo deal was found by Cheapflights users on 9/14. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/234:45 pmONT - LHR
1 stop13h 55mBritish Airways
Tue 10/78:20 amLHR - ONT
1 stop16h 08mBritish Airways
Deal found 9/14$592
This Delta deal was found by Cheapflights users on 9/15. 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.
Wed 9/249:55 amONT - LHR
1 stop15h 55mDelta
Wed 10/16:15 amLHR - ONT
2 stops21h 00mDelta
Deal found 9/15$594
This Delta deal was found by Cheapflights users on 9/15. 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.
Sun 11/1611:45 amONT - LHR
1 stop13h 15mDelta
Thu 11/276:30 amLHR - ONT
2 stops19h 48mDelta
Deal found 9/15$595
This Finnair deal was found by Cheapflights users on 9/15. 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 Finnair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/272:51 pmONT - LHR
1 stop13h 49mMultiple Airlines
Fri 11/79:55 amLHR - ONT
1 stop17h 46mMultiple Airlines
Deal found 9/15$602
This Virgin Atlantic deal was found by Cheapflights users on 9/14. 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 Virgin Atlantic is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/11:20 pmONT - LHR
2 stops15h 30mVirgin Atlantic
Tue 12/911:40 amLHR - ONT
2 stops20h 19mVirgin Atlantic
Deal found 9/14$606
This Delta deal was found by Cheapflights users on 9/14. 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.
Sat 10/411:55 amONT - LHR
1 stop35h 20mDelta
Fri 10/176:00 pmLHR - ONT
1 stop25h 08mDelta
Deal found 9/14$607
This Trip.com deal was found by Cheapflights users on 9/15. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 9/2212:45 pmONT - LHR
1 stop17h 40mIberia
Tue 10/712:00 pmLHR - ONT
1 stop18h 42mIberia
Deal found 9/15$626
This Trip.com deal was found by Cheapflights users on 9/14. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/18:15 amONT - LHR
1 stop16h 45mIberia
Wed 10/812:00 pmLHR - ONT
1 stop18h 42mIberia
Deal found 9/14$627
This oojo deal was found by Cheapflights users on 9/14. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/2110:55 amONT - LHR
1 stop14h 05mBritish Airways
Sat 10/48:20 amLHR - ONT
1 stop22h 13mBritish Airways
Deal found 9/14$642
This Iberia deal was found by Cheapflights users on 9/14. 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 Iberia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/2312:47 pmONT - LHR
1 stop17h 38mIberia
Tue 10/76:10 amLHR - ONT
2 stops24h 32mIberia
Deal found 9/14$644
This United Airlines deal was found by Cheapflights users on 9/14. 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.
Wed 10/297:00 amONT - LCY
2 stops22h 50mMultiple Airlines
Wed 11/59:50 amLCY - ONT
2 stops21h 01mMultiple Airlines
Deal found 9/14$714
This United Airlines deal was found by Cheapflights users on 9/15. 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.
Thu 10/307:00 amONT - LCY
2 stops27h 05mMultiple Airlines
Thu 11/69:40 amLCY - ONT
2 stops21h 11mMultiple Airlines
Deal found 9/15$749

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 September 15, 2025.
Use the filters below to find and compare flights from Ontario to London that are best for you.

Fly from

Ontario

Fly to

London

Route

Depart

Return

Price

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 12/1

1:20 pm-10:00 am

1 stop12h 40m

London Heathrow

Tue 12/9

8:55 am-11:03 pm

2 stops22h 08m

$594

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 10/22

1:15 pm-1:30 pm

2 stops16h 15m

London Heathrow

Wed 10/29

6:20 am-9:20 pm

2 stops22h 00m

$598

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 10/29

6:00 am-7:05 am

2 stops18h 05m

London Heathrow

Wed 11/5

6:20 am-10:41 pm

2 stops24h 21m

$598

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 12/1

6:00 am-10:00 am

1 stop20h 00m

London Heathrow

Tue 12/9

8:55 am-11:03 pm

1 stop22h 08m

$602

OntarioLondon

ONT - LCY

ONTLCY

Ontario

Wed 2/18

1:00 pm-4:35 pm

2 stops19h 35m

London City

Thu 3/5

7:45 am-9:14 pm

2 stops21h 29m

$660

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 10/29

1:33 pm-9:40 am

1 stop13h 07m

London Heathrow

Wed 11/5

1:30 pm-10:51 pm

2 stops17h 21m

$669

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 10/28

1:33 pm-9:40 am

1 stop13h 07m

London Heathrow

Tue 11/4

10:05 am-5:34 pm

1 stop15h 29m

$681

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 10/29

11:48 am-10:30 am

1 stop15h 42m

London Heathrow

Sat 11/15

6:20 am-10:55 pm

2 stops24h 35m

$684

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 11/14

6:45 am-10:30 am

1 stop19h 45m

London Heathrow

Tue 11/18

8:55 am-7:37 pm

1 stop18h 42m

$692

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 10/20

9:50 am-1:30 pm

2 stops19h 40m

London Heathrow

Sun 10/26

10:45 am-11:39 pm

1 stop19h 54m

$696

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/15

Showing 1-10 of 60 results
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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, November is the cheapest month in which you can book a flight from Ontario to London (average of $661). Flying from Ontario to London in June is currently the most expensive (average of $1,097). 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 LON?

Find hourly flight availability from Ontario to London. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated September 15, 2025.

It’s optimal to fly from Ontario to London in the evening. By choosing this option you can save up to 24% on the cost of your flight, compared to a flight in the morning.

What is the cheapest day to fly from Ontario to London?

Use this chart to determine the cheapest time to fly round-trip from Ontario to London. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Ontario to London flight should consider departing on Tuesday afternoons when fares are most often at their lowest. Sunday evenings flights should be avoided if possible as fares are typically the most expensive at this time.

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

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 September 15, 2025.
Get a feel of what it's like to fly with Delta, United Airlines, and American 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
8.0
Very good
7,954 reviews

Comfort

7.9

Food

7.3

Boarding

8.2

Entertainment

7.9

Crew

8.5

Overall

8.0

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
7,954 reviews
Delta
8.0
Very good
7,954 reviews

Comfort

7.9

Food

7.3

Boarding

8.2

Entertainment

7.9

Crew

8.5

Overall

8.0

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
8,929 reviews
Delta
8.0
Very good
7,954 reviews

Comfort

7.9

Food

7.3

Boarding

8.2

Entertainment

7.9

Crew

8.5

Overall

8.0

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.
American Airlines
7.2
Good
10,000 reviews
Delta
8.0
Very good
7,954 reviews

Comfort

7.9

Food

7.3

Boarding

8.2

Entertainment

7.9

Crew

8.5

Overall

8.0

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.
Iberia
7.0
Good
2,924 reviews
Delta
8.0
Very good
7,954 reviews

Comfort

7.9

Food

7.3

Boarding

8.2

Entertainment

7.9

Crew

8.5

Overall

8.0

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
7,361 reviews
Delta
8.0
Very good
7,954 reviews

Comfort

7.9

Food

7.3

Boarding

8.2

Entertainment

7.9

Crew

8.5

Overall

8.0

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 7 airlines. Ontario is conveniently located just 3.1 mi from Ontario’s city center.

  • How long is the flight from Ontario to London?

    Delta, KLM, and United Airlines can get you from Ontario to London in just under 12h 40m. Your travel time can differ by up to 7h 20m. 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 Virgin Atlantic is currently your cheapest option to London, with prices starting at $469. Additional round-trip tickets that might be worth considering are offered by Delta and KLM, with the lowest prices starting at $572 and $580, respectively. You may be able to fly from Ontario to London for 43% less than the average price by searching for these airlines.

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

    The cheapest airlines for a one-way flight from Ontario to London are JetBlue ($374), Delta ($375), and KLM ($379).

  • 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, November is the cheapest month in which you can book a flight from Ontario to London (average of $661). Flying from Ontario to London in June is currently the most expensive (average of $1,097). 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
Hounslow
Hayes
Southend-on-Sea
Harrow
Canterbury
Croydon
Eastleigh
Dartford
Dover
Winchester
Orpington
Gatwick
Borehamwood
Aylesbury
Bedford
Wembley
Folkestone
Chichester
Eastbourne
Sutton

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Alternative routes for Ontario to London

See prices for flight routes from nearby airports that may be better suited for you.
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Top 7 airlines flying from Ontario to London

Discover the top 7 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 September 15, 2025.
AirlineCheapestAverageFlexibilityOn-time
Virgin AtlanticCheapest$469Average$884FlexibilityNo cancel feeOn-time72%
DeltaCheapest$572Average$677FlexibilityNo cancel feeOn-timeN/A
KLMCheapest$580Average$653FlexibilityNo cancel feeOn-time75%
IberiaCheapest$582Average$670FlexibilityNo cancel feeOn-time77%
American AirlinesCheapest$653Average$957FlexibilityNo cancel feeOn-time71%
British AirwaysCheapest$662Average$878FlexibilityNo cancel feeOn-time70%
United AirlinesCheapest$677Average$820FlexibilityNo cancel feeOn-time69%

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