$791 Cheap Flights from London (LHR) to Ontario (ONT)

View $791 flight on Wed, Aug 20, 2025Opens in a new window

Popular airlines from Heathrow Airport (LHR) to Los Angeles - Ontario Intl. Airport (ONT)

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Cheap Flights from London to Ontario (LHR-ONT)

Prices were available within the past 7 days and start at $791 for one-way flights and $584 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

British Airways
Sun, Oct 5 - Sun, Oct 12
LHR
London
ONT
Ontario
$584 Roundtrip, just found
$584
Roundtrip
just found
Select British Airways flight, departing Sun, Oct 5 from London to Ontario, returning Sun, Oct 12, priced at $584 just found
Delta
Wed, Aug 6 - Sat, Jun 6
LHR
London
ONT
Ontario
$584 Roundtrip, found 21 hours ago
$584
Roundtrip
found 21 hours ago
Select Delta flight, departing Wed, Aug 6 from London to Ontario, returning Sat, Jun 6, priced at $584 found 21 hours ago
Virgin Atlantic
Wed, Aug 6 - Sat, Jun 6
LHR
London
ONT
Ontario
$584 Roundtrip, found 21 hours ago
$584
Roundtrip
found 21 hours ago
Select Virgin Atlantic flight, departing Wed, Aug 6 from London to Ontario, returning Sat, Jun 6, priced at $584 found 21 hours ago
Virgin Atlantic
Wed, Aug 6 - Sat, Jun 6
LHR
London
ONT
Ontario
$584 Roundtrip, found 21 hours ago
$584
Roundtrip
found 21 hours ago
Select Virgin Atlantic flight, departing Wed, Aug 6 from London to Ontario, returning Sat, Jun 6, priced at $584 found 21 hours ago
British Airways
Sun, Sep 7 - Sun, Sep 14
LHR
London
ONT
Ontario
$587 Roundtrip, just found
$587
Roundtrip
just found
Select British Airways flight, departing Sun, Sep 7 from London to Ontario, returning Sun, Sep 14, priced at $587 just found
British Airways
Sun, Sep 28 - Wed, Oct 8
LHR
London
ONT
Ontario
$587 Roundtrip, found 18 hours ago
$587
Roundtrip
found 18 hours ago
Select British Airways flight, departing Sun, Sep 28 from London to Ontario, returning Wed, Oct 8, priced at $587 found 18 hours ago
British Airways
Sun, Sep 7 - Tue, Sep 16
LHR
London
ONT
Ontario
$590 Roundtrip, found 21 hours ago
$590
Roundtrip
found 21 hours ago
Select British Airways flight, departing Sun, Sep 7 from London to Ontario, returning Tue, Sep 16, priced at $590 found 21 hours ago
British Airways
Tue, Mar 3 - Tue, Mar 31
LHR
London
ONT
Ontario
$592 Roundtrip, found 4 hours ago
$592
Roundtrip
found 4 hours ago
Select British Airways flight, departing Tue, Mar 3 from London to Ontario, returning Tue, Mar 31, priced at $592 found 4 hours ago
Iberia
Wed, Dec 3 - Fri, Jan 30
LHR
London
ONT
Ontario
$593 Roundtrip, found 2 days ago
$593
Roundtrip
found 2 days ago
Select Iberia flight, departing Wed, Dec 3 from London to Ontario, returning Fri, Jan 30, priced at $593 found 2 days ago
American Airlines
Wed, Aug 20 - Wed, Sep 10
LHR
London
ONT
Ontario
$607 Roundtrip, found 14 hours ago
$607
Roundtrip
found 14 hours ago
Select American Airlines flight, departing Wed, Aug 20 from London to Ontario, returning Wed, Sep 10, priced at $607 found 14 hours ago

Find the cheapest month to fly from London (LHR) to Ontario (ONT)

November is typically the cheapest month to fly

From $504 - $1,344 per traveler.

Graph displaying average flight prices per month

Flights from London (LHR) to Ontario (ONT)
Origin airport
Heathrow
Destination airport
Los Angeles - Ontario Intl.
Airlines serving
Air Canada, American Airlines, British Airways, Delta, Iberia, JetBlue Airways, KLM, United, Virgin Atlantic
Roundtrip price
$583
Distance
5409 mi

London to Ontario Flights

The cheapest times to fly from London to Ontario

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from London to Ontario are during the month of October. You can find some of the cheapest flights from London to Ontario with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from London to Ontario

Sunday is one of the best days to book for cheap flights from London to Ontario: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from London to Ontario

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from London to Ontario in 2025. You can also book with separate airlines for your outbound and return journeys, from $791 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap London to Ontario flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your London to Ontario airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Frequently asked questions

How much does a flight from Heathrow Airport (LHR) to Los Angeles - Ontario Intl. Airport (ONT) cost?
Discover the latest flight deals from LHR to ONT by entering your preferred travel dates and searching on Expedia. Easily compare prices by departure date if you have flexibility with your schedule and use handy filters to explore prices for your preferred journey. As a member of One Key™, our free loyalty program, you can use Price Tracking to watch fares and receive notifications if prices go up or down.
What is the cheapest month to fly from LHR to ONT?
The cheapest flights from LHR to ONT are usually during off-peak season, when demand is lower. To save money, avoid flying during public holidays, school breaks and major local events.
What is the cheapest airline that flies from LHR to ONT?
Use the filter tool on Expedia to compare airlines and find the cheapest carrier that'll take you from LHR to ONT. Sort your results by "Price (lowest to highest)" to snap up a great deal.
How many flights per day from Heathrow Airport (LHR) to Los Angeles - Ontario Intl. Airport (ONT)?
Nonstop flights from Heathrow Airport (LHR) to Los Angeles - Ontario Intl. Airport (ONT) aren't available daily, so you'll need to take a flight with a layover. Explore your options with our filter tool. Enter your dates and pick either "1 Stop" or "2+ Stops."
What day of the week has the most flights from LHR to ONT?
Friday is generally the busiest day for flights, while Tuesday is often the quietest.* Keep in mind that flight schedules can vary depending on various factors, such as the airline and season.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Heathrow Airport (LHR) to Los Angeles - Ontario Intl. Airport (ONT)?
To avoid potential delays on the Heathrow Airport (LHR) to Los Angeles - Ontario Intl. Airport (ONT) route, fly before 3 PM. Departures after this hour have a 22% higher chance of being canceled.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
What airports do you fly into for Ontario from Heathrow Airport (LHR)?
Los Angeles Intl. Airport (LAX) is the only airport in Ontario with direct flights from Heathrow Airport (LHR). Explore your options and find cheap fares on Expedia.
Is it cheaper to buy a plane ticket from Heathrow Airport (LHR) to Los Angeles - Ontario Intl. Airport (ONT) last-minute?
Last-minute bookings from LHR to ONT are usually more expensive. To secure the best prices, start searching for flights ahead of time. That said, if you're flexible with your travel plans, it's possible to find a cheap ticket right before your journey.
Is it cheaper to book a LHR to ONT flight and hotel package?
Compared with arranging hotels and flights separately, booking a LHR to ONT flight and hotel package with Expedia could result in significant savings. Better still, having everything in one place takes the hassle out of travel planning. Simply pick your flights and select from our extensive range of stays, then personalize your trip with other add-ons like tours and car rentals.
Can I cancel or change the date of my flight from Heathrow Airport (LHR) to Los Angeles - Ontario Intl. Airport (ONT)?
In most instances, you can modify or cancel your LHR to ONT flight. However, additional fees may apply, especially if you made your booking over 24 hours ago. Check your itinerary for the airline's fees and rules on flight changes, or if you need further information, visit our Customer Service portal.

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*Available to One Key members.