HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Ontario

$403+ Cheap flights from the United Kingdom to Ontario (ONT)

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 2/3. Fares are subject to change and may not be available on all flights or dates of travel.
LHR — ONT
Jan 20 — Jan 271
Tue 1/20
Tue 1/27
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from United Kingdom to Ontario 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.

Cheap flight deals from United Kingdom to Ontario

Cheapest flights from United Kingdom to Ontario
Explore the most affordable flight options available from United Kingdom to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on December 21, 2025.

This Delta deal was found by Cheapflights users on 12/19. 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.
Sat 12/2710:45 amLHR - ONT
1 stop19h 43mDelta
Mon 1/121:11 pmONT - LHR
1 stop12h 49mDelta
Deal found 12/19$515
This Delta deal was found by Cheapflights users on 12/19. 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.
Sat 12/2710:45 amLHR - ONT
1 stop19h 43mDelta
Sat 1/101:11 pmONT - LHR
1 stop12h 49mDelta
Deal found 12/19$527
This American Airlines deal was found by Cheapflights users on 12/19. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/264:30 pmLHR - ONT
1 stop15h 16mAmerican Airlines
Wed 1/1410:58 amONT - LHR
1 stop13h 37mAmerican Airlines
Deal found 12/19$535
This British Airways deal was found by Cheapflights users on 12/19. 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 British Airways is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/264:30 pmLHR - ONT
1 stop15h 16mBritish Airways
Mon 1/124:45 pmONT - LHR
1 stop12h 30mBritish Airways
Deal found 12/19$544
This United Airlines deal was found by Cheapflights users on 12/20. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/2710:05 amLHR - ONT
1 stop15h 38mUnited Airlines
Fri 1/91:24 pmONT - LHR
1 stop12h 16mUnited Airlines
Deal found 12/20$552
This Kissandfly.com deal was found by Cheapflights users on 12/20. 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 Kissandfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/2710:45 amLHR - ONT
1 stop19h 43mMultiple Airlines
Mon 1/1212:41 pmONT - LHR
1 stop14h 59mMultiple Airlines
Deal found 12/20$568
This United Airlines deal was found by Cheapflights users on 12/19. 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.
Sun 12/2811:35 amLHR - ONT
1 stop17h 32mUnited Airlines
Thu 1/81:24 pmONT - LHR
1 stop12h 16mUnited Airlines
Deal found 12/19$582
This Kissandfly.com deal was found by Cheapflights users on 12/20. 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 Kissandfly.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/2710:05 amLHR - ONT
1 stop15h 38mLufthansa
Mon 1/121:53 pmONT - LHR
1 stop14h 07mLufthansa
Deal found 12/20$587
This British Airways deal was found by Cheapflights users on 12/19. 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 British Airways is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/264:30 pmLHR - ONT
1 stop15h 16mBritish Airways
Wed 12/3112:45 pmONT - LHR
1 stop13h 15mBritish Airways
Deal found 12/19$648
This United Airlines deal was found by Cheapflights users on 12/20. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/2710:05 amLHR - ONT
1 stop15h 38mUnited Airlines
Sat 1/36:39 pmONT - LHR
1 stop28h 46mUnited Airlines
Deal found 12/20$664
This Delta deal was found by Cheapflights users on 12/20. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/296:05 amNCL - ONT
2 stops18h 07mDelta
Thu 1/86:00 amONT - NCL
2 stops20h 20mDelta
Deal found 12/20$671
This oojo deal was found by Cheapflights users on 12/21. 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 12/287:15 pmLCY - ONT
2 stops34h 59mBritish Airways
Sun 1/117:16 amONT - LCY
2 stops41h 34mBritish Airways
Deal found 12/21$894

Find flight deals from United Kingdom to Ontario

Keep the following information in mind while searching for United Kingdom to Ontario flight deals. Data was last updated December 21, 2025.

Most accurate provider

Justfly.com
3 stars

Most trusted provider

Justfly.com
3 stars

Round-trip from

$394

Popular in

December

Cheapest in

September

Average price

$791
Provider with most accurate pricing for London (LON)-Los Angeles flight deals.
Search Deals
Provider most trusted by Cheapflights users for London (LON)-Los Angeles flights.
Search Deals
From United Kingdom to Ontario
Search Deals
Highest demand for flights based on searches. 4% potential increase in price ($32 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($14 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in December 2025
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from United Kingdom to Ontario 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 December 21, 2025.
Use the filters below to find and compare flights from the United Kingdom to Ontario that are best for you.

Fly from

United Kingdom

Fly to

Ontario

Route

Depart

Return

Price

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Mon 1/12

8:55 am-9:05 pm

1 stop20h 10m

Ontario

Mon 1/26

12:41 pm-11:40 am

1 stop14h 59m

$510

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Thu 1/22

7:30 am-9:58 pm

2 stops22h 28m

Ontario

Mon 1/26

1:53 pm-7:25 am

1 stop33h 32m

$511

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Mon 1/12

8:55 am-9:05 pm

1 stop20h 10m

Ontario

Sun 1/25

10:30 pm-7:50 am

1 stop25h 20m

$511

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Tue 4/14

6:30 am-5:15 pm

2 stops18h 45m

Ontario

Fri 4/24

1:20 pm-1:30 pm

2 stops16h 10m

$512

LondonOntario

LHR - ONT

LHRONT

London Heathrow

Fri 2/27

10:45 am-9:05 pm

1 stop18h 20m

Ontario

Sun 3/15

11:59 am-10:30 am

1 stop15h 31m

$516

LondonOntario

LCY - ONT

LCYONT

London City

Mon 2/2

10:00 am-9:05 pm

2 stops19h 05m

Ontario

Mon 2/9

12:41 pm-4:35 pm

2 stops19h 54m

$540

LondonOntario

LCY - ONT

LCYONT

London City

Tue 1/13

7:45 am-9:05 pm

2 stops21h 20m

Ontario

Tue 1/20

12:41 pm-4:35 pm

2 stops19h 54m

$540

LondonOntario

LCY - ONT

LCYONT

London City

Mon 4/13

10:00 am-10:40 pm

2 stops20h 40m

Ontario

Thu 4/23

7:00 am-9:30 am

2 stops18h 30m

$554

Newcastle upon TyneOntario

NCL - ONT

NCLONT

Newcastle upon Tyne

Mon 2/2

9:40 am-10:48 pm

2 stops21h 08m

Ontario

Mon 2/9

3:09 pm-4:00 pm

2 stops16h 51m

$602

GlasgowOntario

GLA - ONT

GLAONT

Glasgow Intl

Thu 3/5

11:30 am-11:58 pm

2 stops20h 28m

Ontario

Mon 3/9

2:47 pm-4:35 pm

2 stops18h 48m

$624

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/20

Showing 1-10 of 60 results
1
2
3
...
6

Best time to book a flight from United Kingdom to Ontario

Have a flexible travel schedule? Discover the best time to fly to Ontario from United Kingdom 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 the United Kingdom to Ontario

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

Currently, September is the cheapest month in which you can book a flight from United Kingdom to Ontario (average of $320). Flying from United Kingdom to Ontario in July is currently the most expensive (average of $539). 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 GB to ONT?

Find hourly flight availability from United Kingdom to Ontario. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated December 21, 2025.

It’s optimal to fly from United Kingdom to Ontario in the afternoon. By choosing this option you can save up to 34% on the cost of your flight, compared to a flight in the morning.

Reviews of airlines servicing Ontario

Get insights into the airlines that provide service to Ontario. 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 Ontario. Reviews last updated December 21, 2025.
Read reviews from past customers who have flown United Airlines from the United Kingdom to Ontario. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
United Airlines
7.4
Good
9,099 reviews

Food

6.6

Boarding

7.7

Entertainment

7.1

Crew

8.1

Overall

7.4

Comfort

7.3

Reviews

1 / 20
10.0
Excellent

Anonymous,Sep 2025

FRA - SFO

Lufthansa was amazing, I wish United States based airlines operated like them.
United Airlines
7.4
Good
9,099 reviews
United Airlines
7.4
Good
9,099 reviews

Food

6.6

Boarding

7.7

Entertainment

7.1

Crew

8.1

Overall

7.4

Comfort

7.3

Reviews

1 / 20
10.0
Excellent

Anonymous,Sep 2025

FRA - SFO

Lufthansa was amazing, I wish United States based airlines operated like them.

Related info for your journey

Find useful and relevant information for your journey from United Kingdom to Ontario. 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 into for flights to Ontario from United Kingdom?

    If you book a flight to Ontario from United Kingdom, you will be flying to Ontario, which is the city’s only airport. Ontario (ONT) is located 3.1 mi from the center of Ontario.

  • How long is the flight from United Kingdom to Ontario?

    Departing from United Kingdom to Ontario will take you 20h 10m. The distance from United Kingdom to Ontario is about 5407 mi. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the most popular routes from United Kingdom to Ontario?

    Most travelers choose London Heathrow - Ontario, Manchester - Ontario or Birmingham - Ontario when deciding on the best route from United Kingdom to Ontario.

  • Can I find deals for flights from United Kingdom to Ontario that include hotel bookings?

    Yes. In addition to deals on United Kingdom to Ontario flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from United Kingdom to Ontario?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from United Kingdom to Ontario.

  • Can I find deals for business class flights from United Kingdom to Ontario?

    Yes. Cheapflights offers flight deals from United Kingdom to Ontario 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 United Kingdom to Ontario?

    Currently, September is the cheapest month in which you can book a flight from United Kingdom to Ontario (average of $320). Flying from United Kingdom to Ontario in July is currently the most expensive (average of $539). 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

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 United Kingdom to Ontario

See prices for flight routes from nearby airports that may be better suited for you.
Charles de Gaulle to Los Angeles flights
Heathrow to Los Angeles flights
Frankfurt to Los Angeles flights
Charles de Gaulle to San Francisco flights
Orly to Los Angeles flights
Frankfurt to Las Vegas flights
Frankfurt to San Francisco flights
Heathrow to Las Vegas flights
Heathrow to San Francisco flights
Charles de Gaulle to Las Vegas flights
Munich to San Francisco flights
Charles de Gaulle to Santa Ana flights
Munich to Los Angeles flights
Frederic Chopin to Los Angeles flights
Frankfurt to Ontario flights
Beauvais-Tille to Los Angeles flights
Istanbul to Los Angeles flights
Frankfurt to Santa Ana flights
Gatwick to Los Angeles flights
Zurich to Los Angeles flights
Vienna to Los Angeles flights
Frankfurt to Long Beach flights
Orly to Las Vegas flights
London City to Los Angeles flights
Malpensa to Los Angeles flights
Charles de Gaulle to Burbank flights
Bruxelles-National to Los Angeles flights
Stansted to Los Angeles flights
Linate to Los Angeles flights
Leonardo da Vinci/Fiumicino to Los Angeles flights
Barcelona-El Prat to Los Angeles flights
Charles de Gaulle to Long Beach flights
Heathrow to Ontario flights
Gatwick to Las Vegas flights
Gatwick to San Francisco flights
Istanbul to San Francisco flights
London City to Las Vegas flights
Amsterdam to Los Angeles flights
Amsterdam to San Francisco flights
Zurich to San Francisco flights
Madrid to Los Angeles flights
Vienna to San Francisco flights
Frankfurt-Hahn to Los Angeles flights
Duesseldorf Intl to Los Angeles flights
Amsterdam to Las Vegas flights
London City to San Francisco flights

Top airline flying from United Kingdom to Ontario

Discover the top airline that operate flights from United Kingdom to Ontario. 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 December 21, 2025.
AirlineCheapestAverageFlexibilityOn-time
United AirlinesCheapest$560Average$694FlexibilityNo cancel feeOn-time69%

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.