$319 Find Cheap Flights from Ontario to the United Kingdom

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 the United Kingdom departing on 10/12. 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

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Cheap Flights from Ontario to the United Kingdom

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours
London
London1 stop$826
Edinburgh
Edinburgh2 stops$847
Manchester
Manchester3 stops$856
Birmingham
Birmingham2 stops$854
Belfast
Belfast2 stops$977
Leeds
Leeds2 stops$1,295
London
London1 stop$826
Edinburgh
Edinburgh2 stops$847
Manchester
Manchester3 stops$856
Birmingham
Birmingham2 stops$854
Belfast
Belfast2 stops$977
Leeds
Leeds2 stops$1,295

Book Cheap Ontario to the United Kingdom Plane Tickets

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

Sun, Sep 27 - Wed, Oct 7
Multiple Airlines Logo
1:05 pm - 3:05 pm
ONT
-
LHR
18h 00m
1 stop
Multiple Airlines Logo
10:50 am - 11:06 pm
LHR
-
ONT
20h 16m
2 stops
$826Multiple Airlines
Tue, Oct 6 - Thu, Oct 15
Multiple Airlines Logo
10:25 am - 2:25 pm
ONT
-
LHR
20h 00m
1 stop
Multiple Airlines Logo
10:50 am - 11:06 pm
LHR
-
ONT
20h 16m
2 stops
$827Multiple Airlines
Wed, Sep 9 - Sat, Sep 19
British Airways Logo
2:22 pm - 12:50 pm
ONT
-
LHR
14h 28m
1 stop
British Airways Logo
8:55 am - 10:37 pm
LHR
-
ONT
21h 42m
1 stop
$829British Airways
Sun, Oct 11 - Wed, Oct 14
United Airlines Logo
6:32 pm - 11:10 am
ONT
-
LHR
32h 38m
1 stop
United Airlines Logo
7:30 am - 8:31 pm
LHR
-
ONT
21h 01m
2 stops
$832United Airlines
Mon, Nov 2 - Thu, Nov 12
British Airways Logo
4:47 pm - 5:00 pm
ONT
-
EDI
16h 13m
2 stops
British Airways Logo
10:20 am - 9:59 pm
EDI
-
ONT
19h 39m
2 stops
$847British Airways
Tue, Nov 3 - Thu, Nov 12
United Airlines Logo
5:00 am - 8:40 am
ONT
-
MAN
43h 40m
3 stops
United Airlines Logo
11:30 am - 10:26 pm
MAN
-
ONT
42h 56m
2 stops
$856United Airlines
Wed, Sep 23 - Mon, Sep 28
Delta Logo
7:05 am - 9:25 am
ONT
-
LGW
18h 20m
2 stops
Delta Logo
10:25 am - 10:40 pm
LGW
-
ONT
20h 15m
2 stops
$907Delta
Wed, Sep 23 - Mon, Sep 28
Delta Logo
7:05 am - 9:25 am
ONT
-
LGW
18h 20m
2 stops
Delta Logo
10:25 am - 10:40 pm
LGW
-
ONT
20h 15m
2 stops
$928Delta
Sun, Sep 6 - Wed, Sep 16
KLM Logo
5:05 pm - 4:55 pm
ONT
-
BHD
15h 50m
2 stops
KLM Logo
9:50 am - 7:57 pm
BHD
-
ONT
18h 07m
2 stops
$1,697KLM
Sat, Aug 8 - Sun, Aug 16
KLM Logo
7:05 am - 9:20 am
ONT
-
BHD
18h 15m
2 stops
KLM Logo
9:50 am - 9:52 pm
BHD
-
ONT
20h 02m
2 stops
$3,047KLM
Booking Insights

KAYAK's insights & trends for Ontario to the United Kingdom flights

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

What is the cheapest month to fly from Ontario to the United Kingdom?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Ontario to the United Kingdom, 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 the United Kingdom is September, when tickets cost $251 (return) on average. On the other hand, the most expensive months are June and July, when the average cost of round-trip tickets is $1,105 and $721 respectively.

Good to know

Low seasonJanuary
Cheapest flight$319
Best time to beat the crowds but there is an average 5% increase in price.
Most popular time to fly and prices are also 30% lower on average.
Flight from Ontario to London Heathrow Airport

FAQs - booking United Kingdom flights

  • How does KAYAK find such low prices on flights from Ontario to the United Kingdom?

    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 the United Kingdom.

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

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

    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 from Ontario to the United Kingdom 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 from Ontario to the United Kingdom?

    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 from Ontario to the United Kingdom 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 the United Kingdom

 
Need help choosing which airline to fly with from Ontario to the United Kingdom? 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
DeltaOverall score based on 8395 reviews
8.5Crew
8.1Boarding
7.2Food
7.8Comfort
7.8Entertainment
Airline reviews

While they turned off most cabin lights to allow people to sleep, I was bothered by how bright the side lights still were. It was still quite bright for me in a window seat, when I wish I could have slept!

10.0 ExcellentTeresa, Apr 2026
SMF - LAX
Read more Delta reviews

While they turned off most cabin lights to allow people to sleep, I was bothered by how bright the side lights still were. It was still quite bright for me in a window seat, when I wish I could have slept!

Generally on time departures and arrivals, clean planes, sky miles membership provides great benefits (complimentary upgrades, etc).

N Everything was perfect from boarding to assistance to baggage in Tampa

Loved the crew! Sucks that we went from 1 hour and 8 minute layover to a 3 hour layover. But weather sucks like that.

Fast, lovely scenery, great info on the Delta flight screen about landmarks we were flying over. Great landing!

Long flight but comfortable and not freezing as I have experienced on Hawaiian flights to the islands. They gave us blankets just in case. Nice touch.

I took seat 15A in anticipation of window seat, there is no window.

Flight late, the waited for a long time for “personal” to arrive at gate to dock the plane in Rochester. So annoying. This flight was expected, why aren’t personel available for the jet bridge?

My recent experience was excellent on Delta! I flew with Delta Comfort and I was really comfortable in my seat. I enjoyed the in-flight service. The flight attendants were so friendly and hospitable. I love the snack on the flight as well. This was my first time flying on Delta and I will definitely consider flying with them again.

My flight was canceled on Sunday. Rebooking took three hours. Had to pay for accommodations another night. New flight was delayed for 5 hours, all that was sent was a 12 dollar food voucher, which doesn’t tell you how to use it. Then when we landed we had to sit on the plane for an hour before we could get off.

As always, it’s a pleasure to travel with KLM. It is one of my favorite airlines.

Brand new plane lots of room the snack was very flavourful and enjoyable

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

Crew is not the cheerful type. very slow meal service (this is their style as have flown this many times)

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

Delay on my previous leg, had to run to catch my flight. But that happens. Overall ok.

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.

Horrifying Almost 2 million miles. Bring your own food and drink. One coffee or drink every three hours. Have to order meals on app more than 24 hours ahead Tiny and dirty bathrooms

Flight was delayed but more than 90 minutes. This caused me to miss my available windows for pick-up by a friend. I had to pay $125 for an uber back home from the airport which was an added expense that I had not budgeted for my trip. Staff was friendly.

Seat pitch is horrible especially on the 15 hour flight. Gate crew at SFO was Outstanding. The flight crew was also great.

Easy of boarding, helpfully staff at check in, surprisingly comfortable seating

Lost of requested seat assignments. Lost my husband's meal choice

My service dog and I were asked to deplane just before they closed the door - clearly very last minute they couldn’t find the documentation that I have filled out many many times before that is for flying service animals. I purposely purchase 3seats (a whole row) since he is large and not all passengers want to sit next to a dog on a cross country flight. The plane departed with my husband on it!!! They made me fill out a hard copy of the same form and had to reschedule me on a later flight where they could find 3 seats together!! I’ve done this so many times before - clearly the error was on their part in a technology glitch - but really people - do better!! Very traumatic - and my husband had to wait for us when he landed ….so bad. Poor pup was confused and tired.

Late plane. Only one crew on the ground so we b had to wait for Denver flight to come in, board, and depart. At 78 yrs of age I was not pleased trying to get my connection. What really made me angry was the notification you sent me to hurry up or I would miss my connection. Why tell me to hurry up when you got me in late. It was not a good way of treating customers.

My flight time was changed without any notification to me which ruined my time sensitive plans so I ended up completely changing my travel plans and no reimbursement.

No screens or meal options. Freezing cold. Dirty seats. Left late.

I liked that my son and I were reseated next to each other (we had different bookings). I liked that it was a directg flight and mostly on time. I liked that you provided pillows and blankets. Flight attendants were generally courteous. The messaging through wifi did not work well. The food was not good. Seats are very narrow and I felt slightly claustraphobic in the window seat.

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

Take-off delayed an hour because of a missing flight officer, so,arrived in Charlotte lates causing many passengers to miss connections. Otherwise a very good flight, safe and comfortable, with an excellent professional crew.

The flight from LA to Chicago was smooth and service was very good overall.

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.

Ontario airport boarding was very easy to park and access, is clean and TSA took 10 minutes total. Check-in was a breeze and cruise was very nice.

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 crew was very attentive through out the flight. Seats were comfortable, nice flight bag with pillow and blanket. Food was okay, since it was a overnight flight seemed to go by fast.

Left early arrived early..right amount of talking from pilots..of course had to love the biscuit and water!

Boarding gate at LAX was too crowded—two gates next to one another

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.

Check-in in SAN was long. ORD was good. Flight delayed On board crew was ok. No warmth or personality. LHrR barely made connection

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

Everything you need to know for your flight from Ontario to the United Kingdom

Information on your arrival and departure airports