ONT - LON

$367 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 10/22. 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

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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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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

Wed, Oct 1 - Thu, Oct 30
Delta Logo
6:00 am - 2:15 pmONT-LHR
24h 15m1 stop
Delta Logo
6:20 am - 10:41 pmLHR-ONT
23h 21m2 stops
$523Delta
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Wed, Oct 1 - Thu, Oct 30
Delta Logo
11:55 am - 11:25 amONT-LHR
15h 30m2 stops
Delta Logo
6:20 am - 10:41 pmLHR-ONT
23h 21m2 stops
$527Delta
Find Deal
Wed, Oct 8 - Wed, Oct 15
United Airlines Logo
9:36 am - 11:50 amONT-LHR
18h 14m2 stops
United Airlines Logo
9:30 am - 9:24 pmLHR-ONT
19h 54m2 stops
$645United Airlines
Find Deal
Tue, Oct 21 - Tue, Oct 28
American Airlines Logo
4:49 pm - 12:50 pmONT-LHR
12h 01m1 stop
American Airlines Logo
2:55 pm - 10:42 pmLHR-ONT
14h 47m1 stop
$647American Airlines
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Wed, Oct 22 - Fri, Oct 31
United Airlines Logo
1:15 pm - 9:40 amONT-LHR
12h 25m1 stop
United Airlines Logo
10:05 am - 5:34 pmLHR-ONT
14h 29m1 stop
$650United Airlines
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Mon, Oct 6 - Wed, Oct 15
Iberia Logo
12:48 pm - 10:50 amONT-LHR
14h 02m1 stop
Iberia Logo
12:00 pm - 7:03 pmLHR-ONT
15h 03m1 stop
$652Iberia
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Mon, Sep 15 - Thu, Oct 16
British Airways Logo
10:53 am - 9:00 amONT-LHR
14h 07m1 stop
British Airways Logo
3:40 pm - 9:49 pmLHR-ONT
14h 09m1 stop
$675British Airways
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Mon, Oct 13 - Wed, Oct 29
Iberia Logo
2:51 pm - 8:00 pmONT-LGW
21h 09m2 stops
Iberia Logo
11:45 am - 10:18 pmLGW-ONT
41h 33m2 stops
$749Iberia
Find Deal
Mon, Dec 29 - Thu, Jan 15
American Airlines Logo
11:59 pm - 7:30 amONT-LGW
23h 31m2 stops
American Airlines Logo
12:30 pm - 2:57 pmLGW-ONT
34h 27m2 stops
$788American Airlines
Find Deal
Tue, Dec 9 - Mon, Dec 15
British Airways Logo
10:47 am - 7:00 pmONT-LGW
24h 13m2 stops
British Airways Logo
7:40 pm - 6:17 pmLGW-ONT
30h 37m2 stops
$938British Airways
Find Deal
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 September, where tickets cost $666 (return) on average. On the other hand, the most expensive months are December and June, where the average cost of round-trip tickets is $1,138 and $1,072 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 11% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 16 weeks before departure.

Good to know

Low seasonJanuary
Cheapest flight$367
Best time to beat the crowds with an average 17% drop in price.
Most popular time to fly and prices are also 7% 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 $367 for a one-way ticket and $523 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?

    oneworld, Star Alliance, and SkyTeam are the airline alliances operating flights between Ontario and London, with SkyTeam 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 $796 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 $829 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 7979 reviews
7.9Comfort
7.3Food
8.5Crew
8.2Boarding
7.9Entertainment
Airline reviews

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

10.0 ExcellentRobert, Jul 2025DTW - LHR
Read more Delta reviews

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.

It would be nice if was given wires ear buds. Overall was a good experience was able to sleep on the plane

737-800 in first class was pretty dumpy. Seat had an uncomfortable angle, storage under the seat was blocked so even my very modest backpack didn't fit, power outlet was flaky. Weird tiny seat pockets that couldn't hold a gallon ziploc bag, emesis bag missing, etc. etc. No in-flight service due to turbulence. Crew was excellent, boarding was smooth despite a full flight.

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.

Not a great experience. We paid for the upgrade for premium economy seats and seated ourselves in very comfortable seats. Someone came along with the same seat on their boarding pass. The aircraft had been changed and as a result we were booted out and sent further back to small uncomfortable seats. After complaining we were moved to emergency row seats, which gave us more leg room but the seats don’t recline. For people in our 70’s we found having to sit upright from California to NJ very uncomfortable. Not sure why they chose to move senior citizens instead of the two people that were allowed to take the more comfortable seats. Not happy.

Everything was great. Only thing that could’ve made it better was buy on board options for hot food, but the snacks were decent. The flight attendants were great. I had no complaints. I was able to make it to my destination safely

Boarded plane and then delayed 1.5 hours while on the plane

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.

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

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.

Again flight was awesome except British Airways lost both gate checked luggage’s. Still missing

really bad they refused to check in luggages that I had purchased, even showing them the transaction receipt from british airways app the staff in miami was MEDIOCRE

Crew was great and responsive. Entertainment quit working with about 4 hours remaining on the flight. My seat cushion was broken.

Not very good , the stewardess were unfriendly and they don't like to be bothered. Cos was a night flight and they need to sleep.

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

Iberia lost my bag, said they found it in another country, said they sent it to me, but never did. Went my whole trip without my stuff, but expecting it to show up because that’s what they said would happen. Their communication sucks, their website sucks, and to top it all off, their seats are small and uncomfortable. They’re bad at their jobs and they should feel bad about themselves. Do not even get me started on the flight home. AVOID!

I described my experience in the previous window. I didn't realize that there would be another opportunity for this flight. Please look at my response in the previous window.

Boarding was 2 1/2 late no explanation Captain said he did not know why, but he rested at home for an extra couple of hours. Food was edible, Nothing more.

I liked the comfort of the plane. It was unexpected from past experiences.

BEWARE!!! Iberia changes your seats at random. I paid for a window seat and they changed it to one in the middle aisle resting against the bathroom- can’t lean back + hear every flush. This on a 11 hour flight.. There were families that were broken up with separate seats all over the plane. Lots of upset passengers showing their seat confirmation to the besieged and helpless airline steward. Also, the gluten free meal was tasteless.

Chair is very high. Your feet cannot touch the ground for 8 hours flight. It was a nightmare. Food was bad.

ground crew and check-in was pathetic - insisted on charging me for luggage even though the ticket said it was already included. They also accidentally sent my luggage through without a luggage tag and had to retrieve it. Generally, it was like a bad movie.

Boarding was efficient and quick, crew was very attentive, seats were comfortable.

Everything was very good! I personally struggled with the heat in the cabin for the first 2 hours

Very caring crew on board. Didn’t have dinner as I was sleeping. Was seating in the emergency row so I had comfortable leg room

Had a nice little suite although I couldn’t close the door (but I didn’t ask anyone to help). 5K is a nice seat and very private (you look in on first class). Enjoyable flight and nice crew.

Although the crew were great and the good nice, I might as well have been on Ryanair for the amount of space I had. Not good enough BA. I’d rather pay more and not feel like a human sardine.

Love the A380 - loads of room. Headphone socket on my seat didn’t work. Sounds like a trivial issue? Well when flying long-haul the in-flight entertainment is what keeps you going so when it doesn’t work it’s a disaster. Pay attention to the details please BA. Spoiled what was otherwise an excellent flight with the usual brilliant crew.

Crew were fantastic can’t fault them at all. Couldn’t do enough for us

Crying baby the ENTIRE flight. Not your fault, but I paid 2700 for a premium economy ticket and it wasn't worth it. should have just stuck with coach. flight attendants very mediocre - minimal effort. Plane didn't seem very clean. Didn't have any cleansing wipes - most airlines give you this when you board. Flat screen scrolling didn't work. Toiletry case a joke - why bother at all?

The overall seat and cushion needs to be updated. It was hard and no support. My butt was numb for most of the flight. The food was subpar at best being in premium economy cost. The flight attendants were excellent and attentive during the whole flight. Disappointed I had to select our seats 24 hours prior.

I enjoyed the comfort of Premium Economy. The Purser on London-Nairobi was a little testy, snappish in his tone. I understand stressed, tired, etc but his tone in addressing passengers I found wanting.

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