ONT - LHR

$294 Find Cheap Flights from Ontario to London Heathrow Airport

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 Heathrow departing on 12/4. 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, 0 bags

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

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Ontario to London.
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Ontario to London.
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Everything you should know

Cheapest round-trip
$587
Overall average: $749
Virgin Atlantic
Tue 12/2Tue 12/16
ONT - LHR • 1 stop
Cheapest one-way
$294
Typical prices: $550-$644
Multiple Airlines
Thu 12/4
ONT - LHR • 3 stops
Top airlines
Virgin Atlantic
Cheapest • from $587 (round-trip)
Delta
Best reviews • 7.9 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
When to travel
November
Cheapest • 25% price drop
September
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
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We hope you love your trip to Heathrow!
Flight Deals
Booking Insights
Flight Deals

Cheap Flights from Ontario to Heathrow (ONT-LHR)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Ontario to Heathrow 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 Heathrow

Tue, Dec 2 - Tue, Dec 16
Virgin Atlantic Logo
6:40 am - 12:50 pmONT-LHR
22h 10m1 stop
Virgin Atlantic Logo
2:45 pm - 10:47 pmLHR-ONT
16h 02m1 stop
$587Virgin Atlantic
Find Deal
Tue, Dec 2 - Tue, Dec 16
Virgin Atlantic Logo
6:40 am - 12:50 pmONT-LHR
22h 10m1 stop
Virgin Atlantic Logo
2:45 pm - 10:47 pmLHR-ONT
16h 02m1 stop
$588Virgin Atlantic
Find Deal
Tue, Dec 9 - Tue, Dec 16
Virgin Atlantic Logo
6:00 am - 6:50 amONT-LHR
16h 50m2 stops
Virgin Atlantic Logo
11:05 am - 11:58 pmLHR-ONT
20h 53m2 stops
$589Virgin Atlantic
Find Deal
Tue, Dec 9 - Tue, Dec 16
Virgin Atlantic Logo
1:29 pm - 10:00 amONT-LHR
12h 31m1 stop
Virgin Atlantic Logo
11:05 am - 11:58 pmLHR-ONT
20h 53m2 stops
$594Virgin Atlantic
Find Deal
Mon, Jan 5 - Tue, Jan 20
Virgin Atlantic Logo
7:30 am - 12:50 pmONT-LHR
21h 20m1 stop
Virgin Atlantic Logo
10:45 am - 4:13 pmLHR-ONT
13h 28m1 stop
$595Virgin Atlantic
Find Deal
Mon, Jan 5 - Tue, Jan 20
Virgin Atlantic Logo
7:30 am - 12:50 pmONT-LHR
21h 20m1 stop
Virgin Atlantic Logo
10:45 am - 11:58 pmLHR-ONT
21h 13m1 stop
$596Virgin Atlantic
Find Deal
Tue, Dec 9 - Tue, Dec 16
Virgin Atlantic Logo
12:40 pm - 12:50 pmONT-LHR
16h 10m1 stop
Virgin Atlantic Logo
2:45 pm - 10:47 pmLHR-ONT
16h 02m1 stop
$599Virgin Atlantic
Find Deal
Fri, Jan 9 - Sun, Jan 18
Virgin Atlantic Logo
7:30 am - 10:30 amONT-LHR
19h 00m1 stop
Virgin Atlantic Logo
12:20 pm - 10:29 pmLHR-ONT
18h 09m1 stop
$615Virgin Atlantic
Find Deal
Mon, Jan 5 - Tue, Jan 20
Delta Logo
3:30 pm - 12:50 pmONT-LHR
13h 20m1 stop
Delta Logo
8:40 am - 9:07 pmLHR-ONT
20h 27m2 stops
$616Delta
Find Deal
Fri, Jan 9 - Sun, Jan 18
Virgin Atlantic Logo
7:30 am - 10:30 amONT-LHR
19h 00m1 stop
Virgin Atlantic Logo
12:20 pm - 10:29 pmLHR-ONT
18h 09m1 stop
$617Virgin Atlantic
Find Deal
Booking Insights

KAYAK's insights & trends for Ontario to Heathrow flights

Get data-powered insights and trends into flights from Ontario to Heathrow 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 Heathrow Airport?

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

If your flying dates are flexible, you should consider flying to London Heathrow Airport on a Wednesday, as we generally find the cheapest rates on that day for this route. On the other hand, Saturday is the most expensive day to fly from Ontario to London Heathrow Airport. For your return ticket, we recommend flying on a Tuesday and avoiding Mondays for the best deals.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Ontario to London Heathrow Airport, 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 Heathrow Airport is November, where tickets cost $624 (return) on average. On the other hand, the most expensive months are June and July, where the average cost of round-trip tickets is $1,310 and $1,011 respectively.

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

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 Heathrow Airport, 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 Heathrow Airport, you should book around 1 week before departure. For the absolute cheapest price, our data suggests you should book 15 weeks before departure.

Good to know

Low seasonJanuary
Cheapest flight$294
Most popular time to fly and prices are also 18% lower on average.
Flight from Ontario to London Heathrow Airport

When to book flights from Ontario to Heathrow

Are your dates flexible? Find out the best times to travel from Ontario to Heathrow 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 Ontario to London Heathrow Airport flights

  • What is the cheapest flight from Ontario to London Heathrow Airport?

    In the last 3 days, the lowest price for a flight from Ontario to London Heathrow Airport was $294 for a one-way ticket and $587 for a round-trip.

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

    A passport is required to fly from Ontario to London Heathrow Airport.

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

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

  • Which airline alliances offer flights from Ontario to London Heathrow Airport?

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

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

    The two airlines most popular with KAYAK users for flights from Ontario to London are Delta and KLM. With an average price for the route of $673 and an overall rating of 7.9, Delta is the most popular choice. KLM is also a great choice for the route, with an average price of $672 and an overall rating of 7.7.

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

    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 Heathrow Airport.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to London Heathrow Airport 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 Heathrow Airport?

    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 Heathrow Airport with an airline and back to Ontario with another airline. Booking your flights between Ontario and LHR can sometimes prove cheaper using this method.

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

    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 Heathrow Airport from Ontario up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top 5 airlines serving from Ontario to Heathrow

 
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 Heathrow? 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 8007 reviews
8.5Crew
7.9Entertainment
8.1Boarding
7.9Comfort
7.3Food
Airline reviews

Plenty of leg room, temperature was great and staff was excellent. Would do it more often.

10.0 ExcellentJacky, Nov 2025JFK - LHR
Read more Delta reviews

Plenty of leg room, temperature was great and staff was excellent. Would do it more often.

Staff were friendly and happy. Delta could make sure passengers that don't have the app know of changes. Without Kayak I would not have known about the change of gate or the delay. Kayak was faster to notify me.

The flight used a B767 with a very old interior from before 2014. The entertainment system did not work at all during the flight despite attempts to reset the system. It was like they flew this route just to be competitive.

Delayed flight (1hour) plus a long layover after an overnight flight with no backup plane available.

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!

They forgot to serve food and the crew was very unfriendly. Never experienced such a bad KLM flight. Usually fly from Toronto. New York was different.

Over 1 Hr delay. No APU so no AC on ground. Plane was hot during boarding and then they closed the doors over 20 minutes before engine start so interior of plane was steamy hot and stuffy. Could have been helped by opening doors until ready to depart.

First of all we couldn’t check in online, then we learn at the airport we were on stand by for KLM’s mistake of overbooking. The seats were not comfy at all. Our luggage got lost.

Ad experience - been flying many years with them but they are losing out to other carriers with their service and bagage / seating policy. My 2 12-yo kids were not placed with the parent. Absurdity.

KLM remains a quality flag carrier airline which maintains its standards whilst all their competitors are lowering theirs.

Our first flight was delayed so we missed our connecting flight. However it was easy to book a later flight on their app.

My flight was delayed by 6 hours then I missed BOTH of my connecting flights, I then had to stay in the AIRPORT at JFK because soooooo many people also suffered from missing flights and there was no hotels available. I would like to be compensated for this experience! I had to stay in the airport for over 16 hours!

The service was great. However the lounge only gets passing grade

I appreciate that KLM was proactive in informing me of the 2 hour delay which enabled me to replan my travel. It was a bit stressful not knowing whether my connection from Montreal to Ottawa was happening. But the ground and air crew did a good job at comforting and assuring me.

Cabin crew professional, polite and friendly, boarding was seemless, but come on KLM surely you can do better than a pack of cheesy biscuits as an inflight snack

Older aircraft, no meal, only food was for purchase. Not impressed United.

Not pleasant trip cross country when the entertainment and WiFi system not working. No entertainment for entirety of route. Staff was rather nonchalant in that they dismissed the problem due to age of plane. It would have been nice to know this up front so I could have come prepared to read or download movies before boarding Coincidentally or not, there was a similar issue with the entertainment system on my previous flight I took on my fist leg of the trip. There are no seat TVs, so you must rely on the app when it works. United can do better. Also, what use it it to pay for boarding group 2 when half of the passengers are in the same line as you?

My experience on this United Airlines flight was highly uncomfortable, primarily due to two issues: Cabin Temperature: The temperature on the Boeing 737 MAX 8 was unacceptably high, feeling consistently around 80 degrees throughout the flight. This made sleeping impossible and significantly detracted from the experience. Seating Arrangement: Being stuck in a middle seat for a six-and-a-half-hour overnight flight compounded the discomfort. Moving forward, I will always purchase a seat assignment to avoid this situation.

Premium Plus is a really good idea for longer flights

Same as last comment. Food sucks. Quality. Not surprising most people have no clue about nourishment Clearly

The flight attendants were great, I joked with one I can’t remember her name, a blond, really sweet. I thought it was run well very professional. This was great i survived Spirit, I know for which I speak.

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.

Disliked having to wait a little longer to disembark from the plan when we landed in London

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.

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.

More choices on menu. Seemed only thing offered was Scottish, and while that’s good for the Scot’s it doesn’t help the Americans who don’t like that food. And I really hate it when, during sleep time the attendants have a very loud conversation right over you. Lastly, I paid 5000 dollars for business class, and having to pay more to choose my seat early is really an insult. Seems greedy

Flying on the Boeing 787 from Seattle to London was everything that I expected. Every thing was great.

Seat pitch is not enough to eat comfortably. When seat in front is reclined, your screen comes closer to your face. Ryanair seats are actually more comfortable.

The leg from Portland to Heathrow was great for a business class ticket. The BA leg from Heathrow to Lisbon was terrible. Basically coach seating with an empty seat between you and next passenger. Absolutely no leg room. Should not have been charged for business class and it was a 3 hour flight.

The flat beds. Other than that, the place was not clean.

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.

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

Information on your arrival and departure airports