HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
London

$266+ 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 2/27. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — LON
feb. 25 — mar. 41
mar. 2/25
mar. 3/4
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Ontario to London with Cheapflights

1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”
2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.
3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

The best prices from Ontario to London are usually found in September or October, booked 73 days in advance, depart on a Wednesday or Tuesday and return on a Tuesday

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 febrero 20, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$613
(Iberia)

One-way from

$266
(Trip.com)

Popular in

June

Cheapest in

September

Average price

$792
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 ($114 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease ($34 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in February 2025
Search Deals

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 febrero 20, 2025.

This Iberia deal was found by Cheapflights users on 2/19. 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 Iberia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 3/107:00 amONT - LHR
1 stop17h 20mIberia
mié. 3/269:25 amLHR - ONT
1 stop21h 29mIberia
Deal found 2/19$613
This Tripair deal was found by Cheapflights users on 2/20. 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 Tripair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
dom. 3/912:46 pmONT - LHR
1 stop34h 34mVirgin Atlantic
mar. 3/2510:45 amLHR - ONT
1 stop20h 11mVirgin Atlantic
Deal found 2/20$629
This Booking.com deal was found by Cheapflights users on 2/19. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
dom. 4/64:35 pmONT - LHR
1 stop12h 15mBritish Airways
mar. 4/223:40 pmLHR - ONT
1 stop14h 18mBritish Airways
Deal found 2/19$634
This Finnair deal was found by Cheapflights users on 2/20. 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 Finnair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
dom. 3/2310:57 amONT - LHR
1 stop15h 43mMultiple Airlines
mié. 4/23:40 pmLHR - ONT
1 stop14h 20mMultiple Airlines
Deal found 2/20$639
This Delta deal was found by Cheapflights users on 2/19. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 3/277:00 amONT - LHR
1 stop16h 20mDelta
jue. 4/106:30 amLHR - ONT
2 stops18h 13mDelta
Deal found 2/19$641
This KLM deal was found by Cheapflights users on 2/19. 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 KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 3/1012:46 pmONT - LHR
1 stop15h 54mKLM
mié. 3/266:30 amLHR - ONT
2 stops17h 12mKLM
Deal found 2/19$645
This Gotogate deal was found by Cheapflights users on 2/19. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 3/105:05 amONT - LHR
2 stops19h 05mAir Canada
mié. 3/263:00 pmLHR - ONT
2 stops36h 57mAir Canada
Deal found 2/19$652
This United Airlines deal was found by Cheapflights users on 2/19. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mar. 3/186:45 pmONT - LHR
1 stop29h 40mUnited Airlines
mar. 3/259:30 amLHR - ONT
2 stops17h 40mUnited Airlines
Deal found 2/19$662
This Trip.com deal was found by Cheapflights users on 2/19. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 2/2010:24 amONT - LGW
1 stop16h 11mMultiple Airlines
jue. 2/2712:00 pmLGW - ONT
1 stop16h 35mMultiple Airlines
Deal found 2/19$691
This JetBlue deal was found by Cheapflights users on 2/19. 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 JetBlue is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 5/110:40 pmONT - LHR
1 stop14h 05mJetBlue
mié. 5/78:15 amLHR - ONT
1 stop21h 07mJetBlue
Deal found 2/19$754
This Delta deal was found by Cheapflights users on 2/19. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mar. 4/17:00 amONT - LCY
2 stops17h 10mDelta
mar. 4/89:20 amLCY - ONT
2 stops21h 03mDelta
Deal found 2/19$781
This The Travel House deal was found by Cheapflights users on 2/19. 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 The Travel House is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 5/121:20 pmONT - LHR
1 stop12h 20mLufthansa
jue. 5/224:15 pmLHR - ONT
1 stop14h 30mLufthansa
Deal found 2/19$793

Find flights from Ontario to London within your budget

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 febrero 20, 2025.

Fly from

Ontario

Fly to

London

Route

Depart

Return

Price

OntarioLondon

ONT - LHR

ONTLHR

Ontario

lun. 3/10

7:00 am-7:20 am

1 stop17h 20m

London Heathrow

mié. 3/26

9:25 am-11:54 pm

1 stop21h 29m

$613

OntarioLondon

ONT - LHR

ONTLHR

Ontario

dom. 3/9

12:46 pm-6:20 am

1 stop34h 34m

London Heathrow

mar. 3/25

10:45 am-11:56 pm

1 stop20h 11m

$629

OntarioLondon

ONT - LHR

ONTLHR

Ontario

dom. 4/6

4:35 pm-12:50 pm

1 stop12h 15m

London Heathrow

mar. 4/22

3:40 pm-9:58 pm

1 stop14h 18m

$634

OntarioLondon

ONT - LHR

ONTLHR

Ontario

dom. 3/23

10:57 am-9:40 am

1 stop15h 43m

London Heathrow

mié. 4/2

3:40 pm-10:00 pm

1 stop14h 20m

$639

OntarioLondon

ONT - LHR

ONTLHR

Ontario

jue. 3/27

7:00 am-6:20 am

1 stop16h 20m

London Heathrow

jue. 4/10

6:30 am-4:43 pm

2 stops18h 13m

$641

OntarioLondon

ONT - LHR

ONTLHR

Ontario

lun. 3/10

12:46 pm-11:40 am

1 stop15h 54m

London Heathrow

mié. 3/26

6:30 am-4:42 pm

2 stops17h 12m

$645

OntarioLondon

ONT - LHR

ONTLHR

Ontario

lun. 3/10

5:05 am-7:10 am

2 stops19h 05m

London Heathrow

mié. 3/26

3:00 pm-8:57 pm

2 stops36h 57m

$652

OntarioLondon

ONT - LHR

ONTLHR

Ontario

mar. 3/18

6:45 pm-7:25 am

1 stop29h 40m

London Heathrow

mar. 3/25

9:30 am-8:10 pm

2 stops17h 40m

$662

OntarioLondon

ONT - LHR

ONTLHR

Ontario

jue. 5/1

10:40 pm-8:45 pm

1 stop14h 05m

London Heathrow

sáb. 5/17

8:15 am-9:22 pm

1 stop21h 07m

$754

OntarioLondon

ONT - LCY

ONTLCY

Ontario

mar. 4/1

7:00 am-8:10 am

2 stops17h 10m

London City

mar. 4/8

9:20 am-10:23 pm

2 stops21h 03m

$781

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/19

Showing 1-10 of 40 results
1
2
3
4

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 February.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
AranGrantPrice Accuracy3 starsTrust Score*1 star

*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.

Travel insights for flights from Ontario to London

Get recent, data-driven insights about flights from Ontario to London including ideal travel times, pricing trends, and more.

How far ahead should I book a flight from Ontario to London?

Use this chart to determine the optimal time to book a round-trip flight from Ontario to London. Price data was last updated on February 14, 2025.

To ensure you get the cheapest price possible for a flight from Ontario to London, 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?

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 $1,136). 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 febrero 20, 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.

Rainfall in London by month

Plan your trip to London by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in London ranges from 1.6 - 2.8 inches per month. January is typically the wettest month, when rainfall can reach 2.8 in. July is typically the driest time to visit London when rainfall is around 1.6 in.

Temperature in London by month

Plan your trip to London by taking into account the average temperature totals by month.

If weather is an important factor for your trip to London, 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 62.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 39.2 F).

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 febrero 20, 2025.
Get a feel of what it's like to fly with Delta, KLM and Virgin Atlantic from Ontario to London by reading reviews from past customers. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Delta
8.0
Very good
8,219 reviews

Food

7.3

Boarding

8.2

Overall

8.0

Entertainment

7.9

Comfort

8.0

Crew

8.5

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
8,219 reviews
Delta
8.0
Very good
8,219 reviews

Food

7.3

Boarding

8.2

Overall

8.0

Entertainment

7.9

Comfort

8.0

Crew

8.5

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
1,333 reviews
Delta
8.0
Very good
8,219 reviews

Food

7.3

Boarding

8.2

Overall

8.0

Entertainment

7.9

Comfort

8.0

Crew

8.5

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
654 reviews
Delta
8.0
Very good
8,219 reviews

Food

7.3

Boarding

8.2

Overall

8.0

Entertainment

7.9

Comfort

8.0

Crew

8.5

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.

Air France
7.4
Good
1,449 reviews
Delta
8.0
Very good
8,219 reviews

Food

7.3

Boarding

8.2

Overall

8.0

Entertainment

7.9

Comfort

8.0

Crew

8.5

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
8,765 reviews
Delta
8.0
Very good
8,219 reviews

Food

7.3

Boarding

8.2

Overall

8.0

Entertainment

7.9

Comfort

8.0

Crew

8.5

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.

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

    Flying on Iberia is currently your cheapest option to London, with prices starting at $613. Additional round-trip tickets that might be worth considering are offered by Virgin Atlantic and British Airways, with the lowest prices starting at $629 and $634, respectively. You may be able to fly from Ontario to London for 20% 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), British Airways ($388), and Virgin Atlantic ($406).

  • 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 $1,136). 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 Ontario?

Book flights to Ontario if you plan to visit one of these locations
Hounslow
Hayes
Thornton Heath
Harrow
Luton
Wembley
Horley
Canterbury
Gatwick
Milton Keynes
Dover
Orpington
Watford
Croydon
Borehamwood
Bromley
Folkestone
Ilford
Aylesbury
Chelmsford

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 London

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
San Francisco to London City flights
San Francisco to Gatwick flights
Los Angeles to Gatwick flights
Ontario to Heathrow flights
San Diego to Heathrow flights
Las Vegas to Heathrow flights
Los Angeles to Luton flights
San Diego to Gatwick flights
San Diego to London City flights
Los Angeles to Stansted flights
San Francisco to Edinburgh flights
Los Angeles to Edinburgh flights
San Jose to Heathrow flights
Oakland to Heathrow flights
Las Vegas to London City flights
Santa Ana to Heathrow flights
San Francisco to Stansted flights
Sacramento to Heathrow flights
San Francisco to Manchester flights
Las Vegas to Gatwick flights
Los Angeles to Manchester flights
San Jose to Gatwick flights
Burbank to Heathrow flights
Sacramento to Gatwick flights
San Diego to Edinburgh flights
Los Angeles to Southampton flights
Los Angeles to Birmingham flights
San Jose to Manchester flights
Ontario to Edinburgh flights
Oakland to Gatwick flights
Los Angeles to Southend flights
San Jose to Edinburgh flights
San Jose to London City flights
San Francisco to Luton flights
San Francisco to Southampton flights
Reno to Heathrow flights
Sacramento to London City flights
Santa Rosa to Heathrow flights
Santa Ana to Gatwick flights
San Jose to Birmingham flights
San Francisco to Birmingham flights
Long Beach to Heathrow flights
Fresno to Heathrow flights
Las Vegas to Edinburgh flights
Medford to Heathrow flights
Reno to Gatwick flights
Sacramento to Edinburgh flights

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 febrero 20, 2025.
AirlineCheapestAverageFlexibilityOn-time
Virgin AtlanticCheapest$454Average$889FlexibilityNo cancel feeOn-time72%
KLMCheapest$481Average$767FlexibilityNo cancel feeOn-time75%
DeltaCheapest$481Average$695FlexibilityNo cancel feeOn-timeN/A
IberiaCheapest$582Average$651FlexibilityNo cancel feeOn-time77%
United AirlinesCheapest$619Average$789FlexibilityNo cancel feeOn-time69%
British AirwaysCheapest$629Average$862FlexibilityNo cancel feeOn-time70%
American AirlinesCheapest$629Average$894FlexibilityNo cancel feeOn-time71%
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.