$451 Find Cheap Flights from the United Kingdom to Ontario

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight to Ontario departing on 4/29. 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 Ontario

 
These are the airlines KAYAK users have selected most often from within our search results for flights to Ontario, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results for flights to Ontario, as well as popular online travel agencies
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Everything you should know

Cheapest round-trip
$492
Overall average: $694
United Airlines
Fri 3/6Thu 3/19
LHR - ONT • 2 stops
Cheapest one-way
$451
United Airlines
Wed 4/29
LHR - ONT • 2 stops
When to travel
September
Cheapest • 22% price drop
November
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 Ontario!
Flight Deals
Booking Insights
Flight Deals

Cheap Flights from the United Kingdom to Ontario

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

Fri, Mar 6 - Thu, Mar 19
United Airlines Logo
1:30 pm - 10:57 pm
LHR
-
ONT
17h 27m
2 stops
United Airlines Logo
1:40 pm - 12:00 pm
ONT
-
LHR
15h 20m
1 stop
$492United Airlines
Sun, Mar 1 - Wed, Mar 11
United Airlines Logo
1:30 pm - 10:57 pm
LHR
-
ONT
17h 27m
2 stops
United Airlines Logo
6:00 am - 6:20 am
ONT
-
LHR
17h 20m
2 stops
$493United Airlines
Fri, Mar 6 - Thu, Mar 19
United Airlines Logo
11:35 am - 8:50 pm
LHR
-
ONT
17h 15m
1 stop
United Airlines Logo
1:40 pm - 12:00 pm
ONT
-
LHR
15h 20m
1 stop
$524United Airlines
Sat, Feb 28 - Sun, Mar 8
Air Canada Logo
1:25 pm - 12:43 pm
LHR
-
ONT
31h 18m
2 stops
Air Canada Logo
6:15 am - 6:30 am
ONT
-
LHR
41h 15m
2 stops
$556Air Canada
Mon, Apr 27 - Sat, May 9
Delta Logo
10:25 am - 10:37 pm
LGW
-
ONT
20h 12m
2 stops
Delta Logo
1:35 pm - 4:00 pm
ONT
-
LGW
18h 25m
2 stops
$627Delta
Thu, Feb 19 - Wed, Feb 25
Iberia Logo
7:50 am - 11:59 pm
LCY
-
ONT
24h 09m
2 stops
Iberia Logo
10:56 am - 2:05 pm
ONT
-
LCY
19h 09m
2 stops
$668Iberia
Mon, Mar 9 - Mon, Mar 30
Iberia Logo
7:15 pm - 1:48 pm
LCY
-
ONT
25h 33m
2 stops
Iberia Logo
2:39 pm - 4:30 pm
ONT
-
LCY
17h 51m
2 stops
$749Iberia
Tue, Mar 17 - Tue, Mar 31
British Airways Logo
10:55 am - 10:06 am
EDI
-
ONT
30h 11m
2 stops
British Airways Logo
5:02 pm - 10:20 pm
ONT
-
EDI
21h 18m
2 stops
$784British Airways
Tue, Mar 17 - Tue, Mar 31
British Airways Logo
10:55 am - 10:06 am
EDI
-
ONT
30h 11m
2 stops
British Airways Logo
5:02 pm - 10:20 pm
ONT
-
EDI
21h 18m
2 stops
$786British Airways
Fri, May 1 - Fri, May 8
Delta Logo
6:00 am - 5:15 pm
GLA
-
ONT
19h 15m
2 stops
Delta Logo
1:25 pm - 4:15 pm
ONT
-
GLA
18h 50m
2 stops
$1,058Delta
Booking Insights

KAYAK's insights & trends for flights to Ontario

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

What is the cheapest month to fly to Ontario?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for flights to Ontario, 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 to Ontario is February, where tickets cost $526 on average for one-way flights. On the other hand, the most expensive months are December and May, where the average cost of tickets from the United Kingdom is $1,019 and $716 respectively. For return trips, the best month to travel is September with an average price of $547.

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

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights to Ontario, 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, you should book around 1 week before departure. For the absolute cheapest price, our data suggests you should book 75 days before departure.

Good to know

Low seasonApril
Cheapest flight$451
Best time to beat the crowds with an average 12% drop in price.
Most popular time to fly and prices are also 1% lower on average.
Flight from London Heathrow Airport to Ontario

FAQs - booking Ontario flights

  • How far is Ontario Airport from central Ontario?

    You’ll need to travel 3 miles to reach the Ontario city center from Ontario Airport.

  • What is the name of Ontario’s airport?

    All flights to Ontario land at Ontario Airport. The airport code is ONT,and it can also be referred to as Ontario or Ontario Intl.

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

    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 to Ontario.

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

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

    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 Ontario with an airline and back with another airline.

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

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

  • How many direct flights to Ontario are there each week?

    Each week there are around 818 direct flights from within United Kingdom to Ontario. The most common day for departures is Thursday, with 16% of flights taking off on this day.

Top tips for finding cheap flights to Ontario

  • Enter your preferred departure airport and travel dates into the search form above to unlock the latest Ontario flight deals.

Reviews of the top airline flying from the United Kingdom to Ontario

 
See real verified KAYAK customer reviews for airlines flying to Ontario. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline from the United Kingdom to Ontario. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with to Ontario? 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.
7.4
United AirlinesOverall score based on 9257 reviews
7.1Entertainment
8.1Crew
7.7Boarding
7.3Comfort
6.6Food
Airline reviews

the whole trip was smooth, and as comfortable as flying is these days. flight crew was friendly and very courteous and helpful.

10.0 ExcellentJanaki, Feb 2026
PDX - SFO
Read more United Airlines reviews

the whole trip was smooth, and as comfortable as flying is these days. flight crew was friendly and very courteous and helpful.

Very poor. The flight was delayed from Toronto because some forget to do there job . I got to my connecting gate in San Francisco 10 minutes before the departure.but this didn’t let me board even though the flight was still there for an other 30 minutes. The the gentleman at the unite airline desk told me that they usually wait for passengers but air Canada called and told them not to we I been rerouted to Manila instead of Hong Kong . In San Francisco they mad me check in my carryon bag . I was told the it will directly go yo ho chi minn cuyt but I was told that by the Vietnams airline desk that’s not there I’m 10 hours behind my scheduled flight and looks like I I’m going without baggage. I don’t have a chance of catching ..

First class ticket gets you a choice of chips or nuts. . Just like economy Southwest. Also no screen in the seats. This is first class???!

Flight arrived 30 min early and bag was waiting at the baggage pickup. United Club HNL was one of the nicest in the system

Mean flight attendant. I wanted to reuse my plastic cup, but he (Matthew) said he can't for safety. I then said "I don't want water then" and he poured me a glass. I hope Matthew gets herpes and spends the rest of his life poor, lonely, and homeless.

Yet another flight in which beverage and snack service was skipped. Other that that, firmly mediocre. Landed early, to gate late due to congestion at the gates. Airline's fault or airports fault: unknown.

Both flights delayed. 2nd flight over 3 hours late mechanical issues

Flight was delayed 45 minutes because originating flight was coming from Newark. No complimentary snacks were offered on this 5+ hour flight. No screens for the flight, but movies offered if you had already downloaded the United app (which I hadn't on my ipad). No USB ports, only a flimsy plug-in port near the bottom of the seat that was hard to see and kept coming unplugged.

It was good but only meal served is very less. Meantime good to add rice and chicken in one of meal

Teeny tiny bathrooms, crew was not realistic about when we'd arrive.

Everything you need to know for your flight to Ontario

Information on the airport you'll fly into in Ontario