ONT - LHR

$321 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 9/22. 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, 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, 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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Everything you should know

Cheapest round-trip
$429
Typical prices: $646-$756
Virgin Atlantic
Thu 12/17Tue 12/22
ONT - LHR • 1 stop
Cheapest one-way
$321
Alaska Airlines
Tue 9/22
ONT - LHR • 1 stop
Top airlines
Cheapest • from $429 (round-trip)
Best reviews • 7.8 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
Nonstop flights
Not available
There are currently no direct flights between Ontario and Heathrow. You'll need at least 1 connection.
Insights
Insights
Insights
Insights
Top layover airports
Cheapest • Avg $580 (round-trip)
Shortest trip • 12h 21m (one-way)
Insights
Insights
Insights
Insights
When to travel
Cheapest • 35% price drop
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
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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 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

Thu, Dec 17 - Tue, Dec 22
Virgin Atlantic Logo
12:00 pm - 11:40 am
ONT
-
LHR
15h 40m
1 stop
Virgin Atlantic Logo
12:20 pm - 10:43 pm
LHR
-
ONT
18h 23m
1 stop
$429Virgin Atlantic
Thu, Dec 17 - Tue, Dec 22
Virgin Atlantic Logo
7:00 am - 11:40 am
ONT
-
LHR
20h 40m
1 stop
Virgin Atlantic Logo
11:40 am - 11:48 pm
LHR
-
ONT
20h 08m
2 stops
$431Virgin Atlantic
Fri, Jul 24 - Sun, Aug 2
Virgin Atlantic Logo
11:59 am - 12:10 pm
ONT
-
LHR
16h 11m
1 stop
Virgin Atlantic Logo
9:40 am - 11:48 pm
LHR
-
ONT
22h 08m
2 stops
$796Virgin Atlantic
Tue, Sep 29 - Tue, Oct 13
Multiple Airlines Logo
10:25 am - 12:50 pm
ONT
-
LHR
18h 25m
1 stop
Multiple Airlines Logo
11:30 am - 11:06 pm
LHR
-
ONT
19h 36m
2 stops
$819Multiple Airlines
Mon, Sep 28 - Thu, Oct 1
Multiple Airlines Logo
10:25 am - 9:05 am
ONT
-
LHR
14h 40m
1 stop
Multiple Airlines Logo
4:25 pm - 11:36 pm
LHR
-
ONT
15h 11m
1 stop
$821Multiple Airlines
Tue, Sep 29 - Tue, Oct 13
Multiple Airlines Logo
5:00 am - 6:30 am
ONT
-
LHR
17h 30m
2 stops
Multiple Airlines Logo
11:30 am - 11:06 pm
LHR
-
ONT
19h 36m
2 stops
$822Multiple Airlines
Sun, Oct 18 - Thu, Oct 29
Multiple Airlines Logo
6:00 am - 10:00 am
ONT
-
LHR
20h 00m
2 stops
Multiple Airlines Logo
8:20 am - 9:08 pm
LHR
-
ONT
19h 48m
1 stop
$825Multiple Airlines
Mon, Sep 28 - Thu, Oct 1
Multiple Airlines Logo
3:14 pm - 3:05 pm
ONT
-
LHR
15h 51m
1 stop
Multiple Airlines Logo
9:15 am - 11:36 pm
LHR
-
ONT
22h 21m
2 stops
$826Multiple Airlines
Mon, Sep 28 - Thu, Oct 1
Multiple Airlines Logo
5:00 am - 10:00 am
ONT
-
LHR
21h 00m
2 stops
Multiple Airlines Logo
9:15 am - 11:36 pm
LHR
-
ONT
22h 21m
2 stops
$827Multiple Airlines
Tue, Sep 22 - Fri, Oct 2
Multiple Airlines Logo
6:00 am - 11:50 am
ONT
-
LHR
21h 50m
2 stops
Multiple Airlines Logo
5:00 pm - 1:21 pm
LHR
-
ONT
28h 21m
1 stop
$828Multiple Airlines
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.

How much is a round-trip flight from Ontario to London Heathrow Airport?

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from Ontario to London Heathrow Airport departing in December.

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 $1,592 and $1,356 respectively.

Good to know

Low seasonJanuary
Cheapest flight$321
Best time to beat the crowds but there is an average 32% increase in price.
Most popular time to fly with an average 41% increase in price.
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 5 days, the lowest price for a flight from Ontario to London Heathrow Airport was $208 for a one-way ticket and $429 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?

    oneworld, SkyTeam, and Star Alliance are the airline alliances operating flights between Ontario and London Heathrow Airport, with oneworld 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 $672 and an overall rating of 7.8, 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 7.8.

  • 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.
7.8
KLMOverall score based on 1531 reviews
7.7Comfort
7.2Entertainment
8.4Crew
7.8Boarding
7.3Food
Airline reviews

As per usual when you Hit the UK it's a slow process through customs Not as efficient at Thailand for sure

10.0 ExcellentDiane, Apr 2026
AMS - HUY
Read more KLM reviews

As per usual when you Hit the UK it's a slow process through customs Not as efficient at Thailand for sure

The crew were unprofessional with a racist element. I was physically abused as well from one of the crew members

Empty seats next to me - wish it had been for a longer flight!!

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.

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

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

Overall very positive. Boarding was quick and organized. Cabin was clean and seats were reasonably comfortable. Cabin crew was excellent and the meals provided were also of good quality

The IFE was quite old, but it worked fine and the content was good. The cabin crew were excellent and the food was as also very good

The plane. Airbus A330-200. Comfortable for a 7-hour flight. Seats seemed to have more legroom. I was in row 17. Flight was operated by Delta but was better than expected.

The crew were efficient. The pilots seemed professional. It was a bit chilly in our seats. The sheet provided weren’t very helpful.

The Boarding process was great. Particularly since my wife and I require assistance. The flight attendants were amazing. We travel frequently; they honestly were a cut above. 😀

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

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

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

All fine save for the abominable catering. Really gone downhill. We found it all inedible.

Late flight caused a missed connection, had to be put on a later international flight without my requested vegan meal.

Half the bathrooms assigned to economy were out of action

The crew members were great. The food was good. Entertainment was average - Could use a wider and better selections of movies and series.

Flight was cancelled after 3 1/2 hours. Support for rebooking was overwhelmed. Lost first class tickets and to fly economy.

I was very disappointed with my experience at the United Airlines baggage check. The representative was rude and unhelpful. I was required to remove approximately 1.5 pounds from my two checked bags, even though it was a very small amount over the limit. The interaction was unnecessarily unpleasant, and I expected much better customer service. I hope United will review this incident and provide additional customer service training to its staff.

Cree was organized and pleasant. Plane had good seating but as it’s a shuttle toilets hadn’t been thoroughly cleaned (eg. bins too full)

Some flight attendants were great others were cranky. Seats were very tight and sitting on an aisle was very hard as the carts and people walking constantly bumped shoulder and arm.

Although the flight was delayed the crew and the flight itself were very good. Couldn't fault anything and after the disappointment of being abandoned in the US by BA it was a welcome relief to travel with United

Liked fold flat bed. Didn’t like having no window. Didn’t like poor choice of food and being served dinner very late, hours after take off of a 7:40pm flight. Servers not friendly. Food horrible in business class.

The flight was heavily booked so boarding was a lengthy process. The FA’s were rather abrupt during this process but became more gracious as the flight went on. Breakfast (puffed pastry and chewy sausage) was pretty horrible but there was fruit and yogurt which they didn’t mess up. Overall it was fine.

Waited for our plane from HNL so we didn't miss connection. AMAZING Service for that, then really clean plane. Nice airline attendants.

The trip was very smooth. Flight crew were very friendly and efficient.

Old plane with broken interiors, unclean restrooms and non attentive crew.

The infotainment system is liking compared to Airlines like Emirates Etihad Singapore Qantas

Luggage did not make it onto my plane. Business seats were economy with empty row seat. Just horrible experience. Why would the company allow for transfers that don’t give employees enough time to transfer luggages??

For an long range economy flight I feel more space and more meal options need to be offered for flights over 5 hours

B-class on an old plane with antiquated amenities and poor service. Landed in Rome w/o bag that didn’t make the connection (plenty of time in London). Bag will come to hotel NOT the day it lands but the following night!! Still waiting for bag…BA had nothing to offer in support and couldn’t even tell me their comp, told to submit receipts and then I’ll learn what is or isn’t covered.

It's a long flight and that is always difficult. I was comfortable and well. The movies available were great and the crew was good.

Premium Economy Good crew, good service, excellent food. Seat back screen just not bright enough.

The business class layout of chairs was weired. You are sitting directly across stranger.,

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.

British Airways staff are very polite and willing to help.

The boarding process was a nightmare and though we were traveling business class, we were in Group 2 and the organization was terrible. The Business Class on this flight was crowded and did not feel clean and nice. Overall, I would not travel Business again on the American Airline flight through British Airways Not nearly special enough for the considerable cost .

not enough crew for business class and not great service as a result. underwhelmed overall

Canceled flight late London to Florence. Help at airport very poor. Treated poorly. Had to sleep in the airport. Lost bags- still do not have them. Horrible. I should be reimbursed!

Boarding was orderly, pilot and flight attendants were nice, entertainment options were good, and low sodium meals were quite tasty.

Flight delayed, connection was not at gate listed and so missed, staff were rude at Heathrow, phone tree stupid and difficult, took me 21 actual hours to reach my destination. Almost lost my hotel reservation after walking in a strange city alone after midnight because they would not put me up in a hotel at sfo or heathrow. I will never fly BA again and will tell all people and Instagram followers never to fly BA.

Wish the food and overall service was better. They treat Business class passengers same as economy

They had us seating down for one hour just waiting on the plane

Flying with BA is always a good experience—even in economy class. It is better if in business and first class. Timely, breeze through security and timely connections

The issue was not with BA it was with the link yoiu sent fopr booking the flight

Loved the boarding option from Business class lounge, experience on flight was excellent, plenty of good food choices

Awful it always is unfortunately is the only way to fly direct to london

Check in was was and the agent was very friendly and helpful The lounge was nice...boarding was straight from the lounge Everything worked at our seats, and video entertainment was good ..food was mediocre

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

Information on your arrival and departure airports