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Cheap flights from Ontario to London from £307

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 20/10. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
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
14:22 - 14:25
ONT
-
LHR
16h 03m
1 stop
Iberia Logo
11:30 - 23:06
LHR
-
ONT
19h 36m
2 stops
£663Iberia
Wed, 9 Sep - Wed, 16 Sep
Iberia Logo
07:20 - 09:00
ONT
-
LHR
17h 40m
1 stop
Iberia Logo
06:15 - 18:57
LHR
-
ONT
20h 42m
2 stops
£664Iberia
Tue, 6 Oct - Tue, 13 Oct
KLM Logo
11:56 - 13:15
ONT
-
LHR
17h 19m
1 stop
KLM Logo
06:30 - 16:14
LHR
-
ONT
17h 44m
2 stops
£666KLM
Sun, 23 Aug - Tue, 8 Sep
Delta Logo
18:01 - 15:35
ONT
-
LHR
13h 34m
1 stop
Delta Logo
06:30 - 23:34
LHR
-
ONT
25h 04m
2 stops
£667Delta
Mon, 3 Aug - Thu, 20 Aug
Delta Logo
22:00 - 06:25
ONT
-
LHR
24h 25m
1 stop
Delta Logo
06:30 - 18:29
LHR
-
ONT
19h 59m
2 stops
£667Delta
Mon, 3 Aug - Thu, 20 Aug
United Airlines Logo
07:00 - 05:55
ONT
-
LHR
14h 55m
1 stop
United Airlines Logo
06:35 - 20:20
LHR
-
ONT
21h 45m
2 stops
£668United Airlines
Mon, 2 Nov - Tue, 17 Nov
Delta Logo
06:00 - 07:10
ONT
-
LHR
17h 10m
2 stops
Delta Logo
06:30 - 18:29
LHR
-
ONT
19h 59m
2 stops
£670Delta
Mon, 3 Aug - Thu, 20 Aug
Delta Logo
12:55 - 13:05
ONT
-
LHR
16h 10m
2 stops
Delta Logo
06:30 - 18:29
LHR
-
ONT
19h 59m
2 stops
£671Delta
Mon, 3 Aug - Thu, 20 Aug
Delta Logo
11:55 - 13:50
ONT
-
LHR
17h 55m
2 stops
Delta Logo
06:30 - 22:40
LHR
-
ONT
24h 10m
2 stops
£673Delta
Sun, 23 Aug - Tue, 8 Sep
British Airways Logo
13:31 - 10:30
ONT
-
LHR
12h 59m
1 stop
British Airways Logo
14:25 - 21:08
LHR
-
ONT
14h 43m
1 stop
£673British Airways
Wed, 9 Sep - Wed, 16 Sep

Iberia flights from Ontario to London

Our best Iberia deals on Ontario to London flight tickets
Iberia
9 Sept
ONT14:22Ontario
16h 03m
1 stop
LHR14:25London Heathrow
16 Sept
LHR11:30London Heathrow
19h 36m
2 stops
ONT23:06Ontario
£663
Iberia
6 Oct
ONT07:20Ontario
17h 40m
1 stop
LHR09:00London Heathrow
13 Oct
LHR06:15London Heathrow
20h 42m
2 stops
ONT18:57Ontario
£664
Iberia
26 Aug
ONT14:27Ontario
15h 58m
1 stop
LHR14:25London Heathrow
12 Sept
LHR11:30London Heathrow
19h 36m
2 stops
ONT23:06Ontario
£702

United Airlines flights from Ontario to London

Our best United Airlines deals on Ontario to London flight tickets
United Airlines
2 Nov
ONT07:00Ontario
14h 55m
1 stop
LHR05:55London Heathrow
17 Nov
LHR06:35London Heathrow
21h 45m
2 stops
ONT20:20Ontario
£668
United Airlines
22 Aug
ONT11:00Ontario
26h 20m
2 stops
LHR21:20London Heathrow
8 Sept
LHR14:10London Heathrow
37h 47m
2 stops
ONT19:57Ontario
£679
United Airlines
22 Aug
ONT13:56Ontario
23h 24m
2 stops
LHR21:20London Heathrow
8 Sept
LHR14:10London Heathrow
37h 47m
2 stops
ONT19:57Ontario
£680

momondo Fare Finder

 
Customise your flight search to find flights from Ontario to London 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 21 May 2026.
Use the filters below to find and compare flights from Ontario to London that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest return flight

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 9/9

14:22-14:25

1 stop16h 03m

London Heathrow

Wed 16/9

11:30-23:06

2 stops19h 36m

£663

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 6/10

07:20-09:00

1 stop17h 40m

London Heathrow

Tue 13/10

06:15-18:57

2 stops20h 42m

£664

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 23/8

11:56-13:15

1 stop17h 19m

London Heathrow

Tue 8/9

06:30-16:14

2 stops17h 44m

£666

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 3/8

18:01-15:35

1 stop13h 34m

London Heathrow

Thu 20/8

06:30-23:34

2 stops25h 04m

£667

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 3/8

22:00-06:25

1 stop24h 25m

London Heathrow

Thu 20/8

06:30-18:29

2 stops19h 59m

£667

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 2/11

07:00-05:55

1 stop14h 55m

London Heathrow

Tue 17/11

06:35-20:20

2 stops21h 45m

£668

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 3/8

06:00-07:10

2 stops17h 10m

London Heathrow

Thu 20/8

06:30-18:29

2 stops19h 59m

£670

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 3/8

12:55-13:05

2 stops16h 10m

London Heathrow

Thu 20/8

06:30-18:29

2 stops19h 59m

£671

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 23/8

11:55-13:50

2 stops17h 55m

London Heathrow

Tue 8/9

06:30-22:40

2 stops24h 10m

£672
Fastest return journey

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 9/9

13:31-10:30

1 stop12h 59m

London Heathrow

Wed 16/9

14:25-21:08

1 stop14h 43m

£673

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

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?

What is the cheapest month to fly to London?

The cheapest month to fly to London from Ontario is in September. Flight prices, which tend to average around £187, are often lower during this time because this is during the off-season. The month of December is another great option to travel to London, with average flight prices from Ontario averaging around £210.

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

Our data shows that Wednesday is the least expensive day to fly to London. Tickets to fly out on this day can be as low as £523. When flying out on a Sunday, the most expensive travel day of the week, you can expect to see flight prices from Ontario to London for around £649.

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

The cheapest time of day to fly to London is in the afternoon when flights can be purchased for as low as £557. Flights in the evening are often more expensive, with an average ticket price of £605.

When to book flights from Ontario to London

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

Cheap Ontario to London (ONT to LON) flight deals and tips

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

Fastest flight time

12h 22m

Direct flights

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

Frequently asked questions about flying from Ontario to London

  • How far is Ontario to London by plane?

    Ontario and London are 5417.5 mi apart from one another. Typically, this will take 12h 22m by plane in normal conditions.

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

    Prices for flights from Ontario Airport to London refresh daily.

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

    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.

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

    The travel and health documents you'll need for your trip to London 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. 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
Gatwick
Luton
Wembley
Slough
Maidstone
Ipswich
Southend-on-Sea
Canterbury
Ilford
Hayes
Guildford
Folkestone
Chelmsford
Dover
Bedford
Chichester
Colchester
Harlow

Why use momondo?

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

Finding the right flight to London from Ontario is quick and easy when you have a range of options in front of you, from reputable agents and recognisable airlines. Options that can then be filtered down to find the best fit. That is what momondo does. We make finding flights to London quick and easy, saving you time and money.

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

Yes. momondo allows you to filter the results for Ontario to London flights to just show those with flexible booking policies.

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

Once you have performed a search for Ontario to London flights, momondo helps you find the right one by offering useful filters to narrow down your flight selection. Flights can be filtered by multiple factors such as airline, airport and price; but also by other criteria like aircraft type and payment method.

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

Of course. momondo tracks the price of Ontario to London flights. All you need is a valid email address and we will do the rest; it is that quick and easy.

An easier way to manage your London trip

We make it super easy to schedule, organise and travel with friends or family. Trips is free – and available to use no matter where you book.
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Find better results for your trip to the United Kingdom

Fly into one of these airports located in London

Airports listed have a maximum distance of 35.6 mi from London
London City Airport
London Gatwick Airport
London Heathrow Airport
London Luton Airport
London Southend Airport
London Stansted Airport