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Cheap flights from Ontario to London from £303

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Ontario to London departing on 10/7. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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0 bags
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Find the cheapest flights from Ontario to London

Cheap return flights

Enter your travel dates to find the best prices.
Iberia Logo
12:35 - 14:25
ONT
-
LHR
17h 50m
1 stop
Iberia Logo
18:45 - 11:48
LHR
-
ONT
24h 03m
2 stops
£654Iberia
Wed, 21 Oct - Wed, 28 Oct
KLM Logo
11:55 - 15:35
ONT
-
LHR
19h 40m
1 stop
KLM Logo
06:30 - 16:14
LHR
-
ONT
17h 44m
2 stops
£657KLM
Sun, 23 Aug - Tue, 8 Sep
United Airlines Logo
13:18 - 09:40
ONT
-
LHR
12h 22m
1 stop
United Airlines Logo
07:25 - 18:16
LHR
-
ONT
18h 51m
2 stops
£658United Airlines
Mon, 17 Aug - Wed, 2 Sep
Iberia Logo
14:22 - 17:15
ONT
-
LHR
18h 53m
2 stops
Iberia Logo
19:40 - 11:48
LHR
-
ONT
23h 08m
2 stops
£660Iberia
Wed, 21 Oct - Wed, 28 Oct
Delta Logo
09:43 - 13:05
ONT
-
LHR
19h 22m
2 stops
Delta Logo
06:30 - 21:52
LHR
-
ONT
23h 22m
2 stops
£661Delta
Mon, 3 Aug - Thu, 20 Aug
Delta Logo
17:06 - 20:10
ONT
-
LHR
19h 04m
2 stops
Delta Logo
11:45 - 23:44
LHR
-
ONT
19h 59m
2 stops
£662Delta
Mon, 17 Aug - Wed, 2 Sep
Delta Logo
11:56 - 13:15
ONT
-
LHR
17h 19m
1 stop
Delta Logo
11:30 - 22:45
LHR
-
ONT
19h 15m
2 stops
£663Delta
Mon, 3 Aug - Thu, 20 Aug
Iberia Logo
14:22 - 14:25
ONT
-
LHR
16h 03m
1 stop
Iberia Logo
19:25 - 21:08
LHR
-
ONT
33h 43m
2 stops
£664Iberia
Wed, 16 Sep - Mon, 5 Oct
United Airlines Logo
13:18 - 09:40
ONT
-
LHR
12h 22m
1 stop
United Airlines Logo
07:30 - 20:16
LHR
-
ONT
20h 46m
2 stops
£666United Airlines
Wed, 23 Sep - Fri, 9 Oct
Air Canada Logo
05:00 - 06:30
ONT
-
LHR
17h 30m
2 stops
Air Canada Logo
14:05 - 20:52
LHR
-
ONT
38h 47m
2 stops
£667Air Canada
Wed, 23 Sep - Thu, 8 Oct

Iberia flights from Ontario to London Heathrow Airport

Our best Iberia deals on Ontario to London Heathrow Airport flight tickets
Iberia
21 Oct
ONT12:35Ontario
17h 50m
1 stop
LHR14:25London Heathrow
28 Oct
LHR18:45London Heathrow
24h 03m
2 stops
ONT11:48Ontario
£654
Iberia
21 Oct
ONT14:22Ontario
18h 53m
2 stops
LHR17:15London Heathrow
28 Oct
LHR19:40London Heathrow
23h 08m
2 stops
ONT11:48Ontario
£660
Iberia
16 Sept
ONT14:22Ontario
16h 03m
1 stop
LHR14:25London Heathrow
5 Oct
LHR19:25London Heathrow
33h 43m
2 stops
ONT21:08Ontario
£664

Air Canada flights from Ontario to London Heathrow Airport

Our best Air Canada deals on Ontario to London Heathrow Airport flight tickets
Air Canada
23 Sept
ONT05:00Ontario
17h 30m
2 stops
LHR06:30London Heathrow
8 Oct
LHR14:05London Heathrow
38h 47m
2 stops
ONT20:52Ontario
£667
Air Canada
23 Aug
ONT05:00Ontario
17h 35m
2 stops
LHR06:35London Heathrow
8 Sept
LHR14:05London Heathrow
38h 47m
2 stops
ONT20:52Ontario
£670
Air Canada
11 Aug
ONT05:00Ontario
17h 30m
2 stops
LHR06:30London Heathrow
27 Aug
LHR08:30London Heathrow
17h 41m
2 stops
ONT18:11Ontario
£681

momondo Fare Finder

 
Customise your flight search to find flights from Ontario to London Heathrow Airport that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, momondo users made 279,928 searches. Data last updated 10 May 2026.
Use the filters below to find and compare flights from Ontario to London Heathrow Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest return flight

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 21/10

12:35-14:25

1 stop17h 50m

London Heathrow

Wed 28/10

18:45-11:48

2 stops24h 03m

£654

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 23/8

11:55-15:35

1 stop19h 40m

London Heathrow

Tue 8/9

06:30-16:14

2 stops17h 44m

£657
Fastest return journey

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 17/8

13:18-09:40

1 stop12h 22m

London Heathrow

Wed 2/9

07:25-18:16

2 stops18h 51m

£658

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 21/10

14:22-17:15

2 stops18h 53m

London Heathrow

Wed 28/10

19:40-11:48

2 stops23h 08m

£660

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 3/8

09:43-13:05

2 stops19h 22m

London Heathrow

Thu 20/8

06:30-21:52

2 stops23h 22m

£661

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 17/8

17:06-20:10

2 stops19h 04m

London Heathrow

Wed 2/9

11:45-23:44

2 stops19h 59m

£662

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 3/8

11:56-13:15

1 stop17h 19m

London Heathrow

Thu 20/8

11:30-22:45

2 stops19h 15m

£663

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 16/9

14:22-14:25

1 stop16h 03m

London Heathrow

Mon 5/10

19:25-21:08

2 stops33h 43m

£664

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 23/9

13:18-09:40

1 stop12h 22m

London Heathrow

Fri 9/10

07:30-20:16

2 stops20h 46m

£666

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 23/9

05:00-06:30

2 stops17h 30m

London Heathrow

Thu 8/10

14:05-20:52

2 stops38h 47m

£667

Flights are sorted by cheapest return flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to London from

How to get the cheapest flight ticket from Ontario to London Heathrow Airport

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the typical price of a round-trip flight between Ontario and London Heathrow Airport?

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

In general, November is the cheapest month to fly from Ontario to London Heathrow Airport. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around £458. The month of September is another great option to travel to London Heathrow Airport, with average flight prices from Ontario averaging around £473.

What is the cheapest day to depart on your flight to London Heathrow Airport?

On average, the least expensive day to fly to London Heathrow Airport from Ontario is on a Wednesday. momondo users have found tickets for Wednesday departures for as low as £528. However, this price may fluctuate depending on the airline, the season, and holidays. Be sure to avoid booking your departure on a Sunday as prices are generally higher than usual. According to our data, the average ticket price to London Heathrow Airport on Sunday is £650.

What is the cheapest time of day to depart on your flight to London Heathrow Airport?

According to our data, the cheapest time of day to fly to London Heathrow Airport is at midday. momondo users have found flights departing from Ontario to London Heathrow Airport at midday for as low as £562. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. If you have a flexible travel schedule, then try to avoid flying in the evening when prices are £594 on average. Flights to London Heathrow Airport from Ontario in the evening are generally more expensive because this time of day is more convenient for travellers’ schedules.

When to book flights from Ontario to London Heathrow Airport

Are you open to changing your travel dates? Check out the ideal times to fly from Ontario to London Heathrow Airport according to our flight data. Find out which month and days have the cheapest flights.
Estimated return price

Cheap Ontario to London Heathrow Airport (ONT to LHR) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Ontario to London Heathrow Airport

Fastest flight time

12h 22m

Direct flights

None
The fastest flight from Ontario to London Heathrow Airport takes 12h 22m
There are no direct flights from Ontario to London Heathrow Airport. There are no popular flight routes from Ontario to London Heathrow Airport.
Search flight deals

Frequently asked questions about flying from Ontario to London Heathrow Airport

  • How far is Ontario to London Heathrow by plane?

    London Heathrow is 5408.1 mi away from Ontario. In terms of flight time, this usually takes a little over 12h 22m.

  • When did momondo last update prices for flights from Ontario Airport to London Heathrow Airport?

    Prices for flights from Ontario Airport to London Heathrow Airport refresh daily.

  • How old do you have to be to fly from Ontario Airport to London Heathrow Airport?

    The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Ontario Airport to London Heathrow Airport.

  • What documentation or ID do you need to fly to London Heathrow Airport?

    The travel and health documents you'll need for your trip to London Heathrow Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at London Heathrow Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

Travelling to a place near London?

Book flights to London if you plan to visit one of these locations
Eastbourne
Milton Keynes
Luton
Gatwick
Stratford-upon-Avon
Wembley
Slough
Maidstone
Northampton
Swindon
Ipswich
Southend-on-Sea
Canterbury
Ilford
Hayes
Guildford
Poole
Folkestone
Chelmsford
Dover

Why use momondo?

Why should I use momondo to find a flight deal from Ontario to London?

momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from Ontario to London . Millions of users trust and use momondo every year so you are in good hands.

Can I find flights from Ontario to London with flexible booking policies on momondo?

Flights from Ontario to London with flexible booking policies can be found by using the search form above and then selecting our dedicated flexible booking filter, which will highlight only the flights where this policy is applied.

How can momondo help me find flights from Ontario to London?

Once you have performed a search in the form on the page, momondo provides useful filters and insights. We can show you the cheapest days and times to fly as well as help filter your options to help you make an informed choice when booking flights to London from Ontario.

I’m not ready to book a flight from Ontario to London right now. Can momondo alert me if prices change?

Price alerts on flights to London from Ontario are quick and easy to set up on momondo. Simply perform a search and select the price alert feature. It is as simple as that.

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