ONT - LON

$381 Find Cheap Flights from Ontario to London

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Ontario to London departing on 2/8. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy

KAYAK searches hundreds of travel sites at once for deals on flights to London

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Ontario to London, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Ontario to London, as well as popular online travel agencies
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Flight Deals

Cheap Flights from Ontario to London (ONT-LON)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Ontario to London that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Ontario to London

Tue, Oct 28 - Thu, Nov 27
Delta Logo
11:36 am - 9:00 amONT-LHR
14h 24m1 stop
Delta Logo
6:30 am - 7:42 pmLHR-ONT
21h 12m2 stops
$652Delta
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Tue, Nov 11 - Tue, Nov 25
Delta Logo
7:05 am - 8:45 amONT-LHR
17h 40m2 stops
Delta Logo
8:40 am - 11:04 pmLHR-ONT
22h 24m2 stops
$656Delta
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Mon, Jan 5 - Tue, Jan 20
United Airlines Logo
6:04 am - 10:15 amONT-LHR
20h 11m1 stop
United Airlines Logo
9:30 am - 9:58 pmLHR-ONT
20h 28m2 stops
$660United Airlines
Find Deal
Tue, Oct 28 - Tue, Nov 25
British Airways Logo
10:57 am - 6:50 amONT-LHR
12h 53m1 stop
British Airways Logo
4:30 pm - 11:57 pmLHR-ONT
15h 27m1 stop
$673British Airways
Find Deal
Mon, Jan 5 - Tue, Jan 20
United Airlines Logo
11:59 pm - 6:40 amONT-LHR
22h 41m2 stops
United Airlines Logo
8:30 am - 9:58 pmLHR-ONT
21h 28m2 stops
$674United Airlines
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Sun, Mar 29 - Wed, Apr 8
Iberia Logo
10:57 am - 8:05 amONT-LHR
13h 08m1 stop
Iberia Logo
10:50 am - 11:40 pmLHR-ONT
20h 50m2 stops
$675Iberia
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Tue, Mar 17 - Tue, Mar 31
British Airways Logo
10:57 am - 6:50 amONT-LHR
12h 53m1 stop
British Airways Logo
3:40 pm - 9:40 pmLHR-ONT
14h 00m1 stop
$681British Airways
Find Deal
Tue, Jan 27 - Wed, Feb 4
Iberia Logo
7:16 am - 10:50 amONT-LGW
19h 34m2 stops
Iberia Logo
11:45 am - 2:18 pmLGW-ONT
34h 33m2 stops
$704Iberia
Find Deal
Sat, Nov 8 - Fri, Nov 21
American Airlines Logo
10:34 pm - 9:00 amONT-LGW
26h 26m2 stops
American Airlines Logo
11:20 am - 11:57 pmLGW-ONT
44h 37m2 stops
$825American Airlines
Find Deal
Wed, Mar 4 - Sun, Mar 8
American Airlines Logo
6:47 am - 9:00 amONT-LGW
18h 13m2 stops
American Airlines Logo
12:30 pm - 9:29 amLGW-ONT
27h 59m2 stops
$1,000American Airlines
Find Deal

Everything you should know

Top airlines
Delta
Cheapest • from $652 (round-trip)
Delta
Best reviews • 7.9 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
When to book
4 weeks
in advance
Our data shows that travelers who book at least 4 weeks in advance save around 12% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
October
Cheapest • 14% price drop
April
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
Cheapest round-trip
$652
Typical prices: $696-$1,048
Delta
Tue 10/28Thu 11/27
ONT - LHR • 1 stop
Cheapest one-way
$381
British Airways
Sun 2/8
ONT - LHR • 1 stop
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KAYAK searches 100s of sites at once to find you the best travel deals.
We hope you love your trip to London!
Booking Insights

KAYAK's insights & trends for Ontario to London flights

Get data-powered insights and trends into flights from Ontario to London to help you find the cheapest flights, the best time to fly and much more.

What’s the cheapest day of the week to fly from Ontario to London?

The average price of all round-trip flights from Ontario to London clicked on KAYAK for each day over the last 12 months.

For Ontario to London, Wednesday is the cheapest day to fly on average and Saturday is the most expensive. Flying from London back to Ontario, the best deals are generally found on Tuesday, with Monday being the most expensive.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Ontario to London, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Ontario to London is October, where tickets cost $678 (return) on average. On the other hand, the most expensive months are June and July, where the average cost of round-trip tickets is $1,064 and $926 respectively.

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

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Ontario to London, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from Ontario to London, you should book around 4 weeks before departure, which saves you about 12% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 15 weeks before departure.

Good to know

Low seasonJanuary
Cheapest flight$381
Best time to beat the crowds with an average 9% drop in price.
Most popular time to fly and prices are also 4% lower on average.
Flight from Ontario to London Heathrow Airport

When to book flights from Ontario to London

Are your dates flexible? Find out the best times to travel from Ontario to London based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking flights from Ontario to London

  • How can I get to the city center by public transport after my flight from Ontario to London?

    Upon arrival at London Heathrow Airport from Ontario, you can easily reach the city center using public transportation. Take the Heathrow Express train to Paddington Station, which operates every 15 minutes. From Paddington, you can transfer to the London Underground and take the Bakerloo Line or Circle Line to reach the city center.

  • Can I pre-book my seat on WestJet flights from Ontario to London?

    Yes, you can pre-book your seat on WestJet flights from Ontario to London. WestJet offers the option to select your preferred seat in advance, allowing you to secure your desired seating arrangement for a more comfortable journey. By accessing their online booking portal or contacting their customer service, you can make seat reservations according to your preferences and availability.

  • Which kid-friendly amenities does WestJet have on flights from Ontario to London?

    WestJet offers several kid-friendly amenities on flights from Ontario to London. These amenities include children's entertainment options such as movies, TV shows, and games suitable for different age groups. They also provide complimentary activity packs with coloring books, crayons, and puzzles to keep young travelers engaged during the flight.

  • What are the baggage restrictions when flying Virgin Atlantic from Ontario to London?

    The baggage restrictions when flying Virgin Atlantic from Ontario to London include a checked baggage allowance of two pieces weighing up to 50 lbs each in Economy class. Additionally, passengers are allowed one carry-on bag weighing up to 22 lbs and one personal item such as a laptop or handbag.

  • What is the cheapest flight from Ontario to London?

    In the last 3 days, the lowest price for a flight from Ontario to London was $381 for a one-way ticket and $652 for a round-trip.

  • Do I need a passport to fly between Ontario and London?

    A passport is required to fly from Ontario to London.

  • Which aircraft models fly most regularly from Ontario to London?

    We unfortunately don’t have that data for this specific route.

  • Which airline alliances offer flights from Ontario to London?

    Star Alliance, SkyTeam, and oneworld are the airline alliances operating flights between Ontario and London, with Star Alliance being the most commonly used for this route.

  • Which is the best airline for flights from Ontario to London, Delta or United Airlines?

    The two airlines most popular with KAYAK users for flights from Ontario to London are Delta and United Airlines. With an average price for the route of $854 and an overall rating of 7.9, Delta is the most popular choice. United Airlines is also a great choice for the route, with an average price of $818 and an overall rating of 7.4.

  • How does KAYAK find such low prices on flights from Ontario to London?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Ontario to London.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Ontario to London?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to London from Ontario is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Ontario to London?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to London with an airline and back to Ontario with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Ontario to London?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to London from Ontario up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

KAYAK’s top tips for finding a cheap flight from Ontario to London

  • Common layover options for Air Canada flights from Ontario (ONT) to London (LON) may include stopovers in major hub cities such as Toronto, Montreal, or Ottawa. These layovers often provide convenient connections for passengers, allowing them to change planes and continue their journey to London.
  • Additionally, Air Canada offers a special food service called "Chef's Menu" on its flights from Ontario to London. Passengers can enjoy a delectable selection of culinary delights prepared by renowned chefs. The menu features a range of gourmet dishes using fresh, locally sourced ingredients, ensuring a delightful dining experience in the skies. From appetizers to main courses and desserts, Air Canada's Chef's Menu promises to satisfy the taste buds of travelers throughout their journey.
  • Air Canada offers a variety of in-flight entertainment options on its flights from Ontario to London. Passengers can enjoy a selection of movies, TV shows, and music, with a wide range of genres to choose from. Additionally, the airline provides personal screens with touch controls, offering a seamless and enjoyable viewing experience.
  • WestJet assists passengers with disabilities traveling from Ontario to London. They offer wheelchair assistance, accessible seating options, and priority boarding. Passengers can request special services such as mobility aids or medical equipment during their journey. WestJet's trained staff is available to ensure a comfortable and safe travel experience for passengers with disabilities, addressing their specific needs and providing necessary support throughout the journey.
  • You can change your seat when flying with WestJet from Ontario to London. Seat changes are subject to availability, and you can make the change either during the booking process or by accessing your reservation online. Alternatively, you can contact WestJet's customer service for assistance with seat changes.

Reviews of the top 5 airlines serving from Ontario to London

 
See real verified KAYAK customer reviews for airlines flying from Ontario to London. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Ontario to London? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
7.9
DeltaOverall score based on 7971 reviews
7.9Comfort
7.3Food
8.2Boarding
7.9Entertainment
8.5Crew
Airline reviews

Passengers need to check in big baggage instead of bringing on the plane. That cause inconvenience for everyone. Otherwise flight was good.

8.0 ExcellentTarun, Sep 2025MCO - LHR
Read more Delta reviews

Passengers need to check in big baggage instead of bringing on the plane. That cause inconvenience for everyone. Otherwise flight was good.

Flight delayed for two and half hours and then canceled altogether due to mechanical issues. No mechanic onsite to fix so had to send one from LAX.

Great. Very smooth. Plenty of information. However, wish they would give out a menu in advance of making a dinner choice like other international airlines. The flight attendant says chicken or pasta and there are details about ingredients or spices requiring the passenger to ask which requires the flight attendant to answer many times. So easy to solve this problem. P

My husband upgraded our seats and I don't know if it was due to the type of planet was or if they didn't upgrade our seats. We were supposed to be in I believe comfort seats and they were just as tight as any other seat- no leg room and we are very tall people but at least it wasn't extremely cold. My husband did put in a complaint about our seating because he paid extra and if we would have known that the space and the tightness would have been the same, we just would have gotten the emergency row emergency row seats that we normally get. We love Delta but both our flights coming home we're not good. Oh I forgot to mention that on our flight to Hawaii our luggage wheels got broke and we had to purse new luggage on vacation then we never had this problem so we didn't know protocol and reported it after we got home only for them to tell is we only had 24hrs to report the damage. Not sure what was going on with Delta this vacation trip.

Crew was excellent. Comfort seats not as nice as other kinds of planes.

It was a great flight and the stewards and stewardess were all kind and accommodating!! The seats were comfortable and entertainment screen excellent!

There are 4 flights in consecutive gates with about the same departure time. Two flights were boarding at the same time. One was delayed or boarding would be happening at the same time. I am not sure what Delta and LAX need to do to have a better layout at the end of Terminal 2

There was a security issue at the airport and we were unable to land. We circled endlessly and then landed at another airfield for fuel. We then circled the airport again, almost landed but didn’t fully touch down before circling again. I am thankful to the crew for keeping us safe- the issue was the airline and staff at the airport getting us seats on our connecting flights. That part was hours of searching for someone and getting in double my steps.

Most aspects were good however if they assign boarding zones they ought to enforce them or why bother? My luggage from SAN-JFK-MAD was lost in NY so I without my main bag for two days upon arrival in Spain. They were helpful in tracking it and eventually delivered it to my hotel. The flub was because of a delay upon arrival in NYC. I had booked 2 1/2 hours between flights but we had to hold on the taxiway for an hour after landing while waiting for a clear gate which likely caused the baggage error.

Excellent flight, the planes were newer, they did a nice job with boarding, great service overall.

We were in business class. the angled seats in that class do not have a real window view & the placement of the controls are bad. But we knew that. But the food options were mediocre. The taste was fine, but the size was for a child. It’s just really feels like United is skimping on everything. Even when we were in the Polaris lounge they did not have diet sodas. They said they were out no Coke zero no Diet Coke, etc. I do not think the portion of nuts they serve on the plane could get any smaller. Really a minimal service and offer for what you’re paying for in business.

I was in first class. The outlets at my seat did not work. The plane was shabby and run down. I had prepurchsed a day subscription for internet that was not redeemable. I had to repurchase the internet for my flight and then it didn’t work anyway. Quite disappointed in what was supposed to be the launch of a great vacation.

We had to deboard 2 times due to maintenance issues. They changed the plane, and then we got deviated to LAX due to maibtenance issues on the other plane, had to sleep at LAX and los a full day.

From the first moment you interact with United Airlines, you can expect nothing less but extreme frustration. The baggage handler at the bag drop seems completely unbothered by the presence of customers waiting in line. No help was extended to load the baggage whatsoever. And if any of your bags is overweight by 0.01 pound they will make you re-distribute everything in your suitcase just to play power trip. When it was time to board no help was extended to customers to locate their seats. Moreover. It was a chaotic mess at the gate when it was unclear who should board first and everyone just bunched up, trying to get on the plane. I am sure the crew was doing their best to perform their jobs while being paid their wages however it shouldn’t be that hard to smile once or twice when you’re in the business if serving customers. It is a shame for the United States of America to have a flagship carrier of such low caliber. Our flight was also delayed by about an hour and a half due to further delays prior to our inbound flight. Being someone who has travelled for both business and leisure in Asia, Europe, and South America I have never experienced such poor quality of service.

I understand stuff happens, but plane failures are likely due to lack of maintenance. Additionally, air conditioning wasn't working, no snack/drink service, no WiFi. Fortunately, the crew was communicative and light-hearted. United grabbed another plane and we were able to get to our destination.

The pilots were late and it made us 1 hour late. The meat was tough and bok choy was also tough.

Stuck on tarmac for two hours plus a 5.5 hour flight. Rude flight attendant. And no meals, not even for purchase!

I learned that seating towards the end of plane that a line forms for the restroom and people use your chair as a hand railing, bumping your seat consistently. I was seated in the aisle. I think that next time if I am towards the back row I would want to sit in the middle or window seat.

The best airline I have ever travel , really good customer service, attention and service !!

United sent me a mileage plus number last year but that number is invalid so I can’t use it to check into flights or collect mileage. There is human to speak about the problem, only computers who keep asking me if I am using the correct email. It’s so frustrating and I cannot resolve it.

Food should be better quality. Video screens have poor resolution and the library of movies is poor. The other airlines are much better.

The trip was smooth but the crew were very abrupt, snatching things before finished and being quite snappy when asked questions.

My wife and I love to travel, so we fly a lot. We've already logged 381,075 miles and with practically every major airline. But this flight was very disappointing. It started off well, with no delays and a new plane. But when lunchtime approached, all that good impression was ruined. Instead of white tablecloths, we were offered small, dark placemats, which, as it turned out, were perfectly adequate for the food. All the food offered—and my wife and I only took fish, and the meat—was not just bad, it was downright disgusting and not heated enough. The same applies to the appetizers. This was the first time in many years of traveling that we've been offered such disgusting food.

Lost luggage stuck no clothes and no word after 2 days leaving on cruise no stuff or clothes

Don’t know they cancelled the flight day before I was to leave. They sent a email at 9:00 pm at night saying they cancelled. That is the smooth way to say we don’t want your business! I think they didn’t have enough people booking so they cancelled the flight! It’s all about the money anymore there is no honesty in business.

The flight was canceled 3 hours after original take off time

Pathetic check in experience at JFK. Everything is self check in. Not enough staff present to help with when the check in process or the kiosk gets stuck. Staff present not welcoming or pleasant at all. On the other hand the NY based flight crew was great. Courteous and friendly throughout the flight. Special meals leave a lot to be desired. Kids meals should be made available when kids are flying and same goes for special kids meals too.

The chair cushions may need an upgrade. I have been noticing they are so worn out, thin so you’d sit in a dip 😄. Other than that, all was an enjoyable trip. Thanks AA!

Flight was full, and would have preferred an aisle seat, but due to getting a late ticket ,the seat I had was adequate. The flight crew were very help full and hard working. Food and drink were excellent for the 11hr flight. Overall I was pleased with flight, and would recommend British Airways again.

The chicken adobo was a little too spicy but good otherwise. My personal opinion. Movie selection could be improved, too many horror movies. Could add a few more chick flicks! The flight was bumpy at times. We arrived a little early too! Flight attendants friendly.

Terrible customer service. I booked business class and the counter agent didn’t bother asking me about any choice or preferred seat, basically assigned me that last seat and couldn’t even answer if it was a business class seat. Also iberia lost my suitcase on my flight from JFK to MAD with the layover in BCN. Useless customer service at the counter. Thank goodness I happened to check the baggage claim area of the next flight in…there it was.

Disaster. Downgraded. Zero apology. No effort or coordination between gate and crew. Awful seat blocked by door emergency slide box. Iberia is a mess. App never works. Avoid this airline.

We departed late but made up most of the time in flight. Our ticket was pure economy, so it wasn’t anything fancy; however, I heard that we arrived in Madrid at the exact same time that First Class passengers arrived! Overall, our experience was similar to what we had on other American Airlines transatlantic flights - good value at a reasonable price. We were even able to get our carry-on baggage onto the plane without needing to gate check it.

The crew were friendly and helpful. Iberia lost our luggage on arrival, Friday and we didn't get it until Sunday at 10:00 p.m. local Malaga time. I also paid $382.80 for seat assignments but two out out of the four were not together. Iberia mentioned that it was because the plane was delayed in Madrid before our flight began in LAX. They should compensate us half of my payment.

It was fortunate that the flight arrived in London in accordance with schedule, and the luggage was promptly transferred to the luggage carousel. However, I find it concerning that even minor issues in economy cabins are prevalent within the industry. American Airlines, in particular, appears to have the least legroom and feels more crowded due to the proximity of neighboring passengers. Additionally, the crew’s adherence to protocol is inconsistent. While they may enforce certain rules set by the FAA on a select few individuals, they often overlook numerous violations, such as failing to reset seat recline during landing.

Easy and organized getting in and out of the flight

We liked the flight but while we purchased an aisle seat, our seats had a different configuration on this flight. A fellow passenger suggested that the airplane had been changed. Too bad we were not informed and had no chance to modify our seat preferences. We were stuck in the window and middle seats with no chance to walk around and go to the bathroom without disturbing our sleeping fellow passenger.

The crew were not very personable. The crew did not serve tea or coffee. The bathroom was not kept clean. Two out of the 5 toilets in the cabin weren't working.

It was extremely cold in the back of the plane. The seats are uncomfortable and space very small. Crew was excellent as usual.

Check in needed to be in person, not nice. Also I won’t do connections in Charlotte again because you need to go through security again and short connections become a problem

Moved me away from my family and refused to fix it.

I have always been pleased with their service. Would not change a thing

Seating and food was the worst we have experienced in 35 years of traveling for both personal and busines .

Economy seats felt more cramped than other flights we have taken.7 hr, painful sitting hours 6 and 7. Web site difficult to deal with. Originally put in for 1 special meal due to type 2. Meal was awful. Tried to change selection to standard for return flight, on app and website, unable to complete that action.

I was sleeping during dinner service, no one bothered to offer meal later, I remained hungry….until I got a morning sandwich!

Need to offer Better food from LAX to London Service from London to Delhi very delayed after take off.

Connection at Hethrow was horrible..We couldn't get out of the plane for an hour as they were buying people to the airport and there were not enough busses. We had 2 and half hf between flights so it was very tight. After departing plane we had to go thru security again. People with less time in between connections missed their flights

Horrible… I was downgraded without notice, had to sit in economy and given my back injury was in pain most of the journey. I expect to be reimbursed for this inconvenience and after my return flight home, I never plan to fly with British Airways again.

Great crew and food and beverage. Seating tight but not the airline's fault. Will definitely fly BA in future!

The seating has become ridiculous… like a contest to see how narrow and short they can be made- forcing anyone over 5’1 to pay more to not be twisting oneself into a pretzel. Really insane- would have thought BA was better than this. Frankly- it cancels out a lot of the positive aspects.

Everything you need to know for your flight from Ontario to London

Information on your arrival and departure airports

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