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Cheap flights from Ontario to London from £311

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 9/5. 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
1 adult, Economy, 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.
Delta Logo
17:55 - 15:35
ONT
-
LHR
13h 40m
1 stop
Delta Logo
09:55 - 21:00
LHR
-
ONT
19h 05m
2 stops
£636Delta
Wed, 15 Apr - Tue, 5 May
Delta Logo
06:00 - 07:10
ONT
-
LHR
17h 10m
2 stops
Delta Logo
06:30 - 17:15
LHR
-
ONT
18h 45m
2 stops
£639Delta
Wed, 15 Apr - Tue, 5 May
Air Canada Logo
05:10 - 06:30
ONT
-
LHR
17h 20m
2 stops
Air Canada Logo
10:15 - 17:28
LHR
-
ONT
39h 13m
2 stops
£642Air Canada
Wed, 15 Apr - Thu, 21 May
United Airlines Logo
05:45 - 11:35
ONT
-
LHR
21h 50m
1 stop
United Airlines Logo
09:30 - 21:59
LHR
-
ONT
20h 29m
2 stops
£644United Airlines
Sun, 23 Aug - Tue, 8 Sep
Air Canada Logo
05:10 - 06:30
ONT
-
LHR
17h 20m
2 stops
Air Canada Logo
09:30 - 20:42
LHR
-
ONT
43h 12m
2 stops
£645Air Canada
Wed, 15 Apr - Fri, 22 May
British Airways Logo
10:59 - 07:55
ONT
-
LHR
12h 56m
1 stop
British Airways Logo
10:05 - 16:22
LHR
-
ONT
14h 17m
1 stop
£648British Airways
Wed, 29 Apr - Fri, 15 May
United Airlines Logo
07:00 - 06:55
ONT
-
LHR
15h 55m
2 stops
United Airlines Logo
17:40 - 18:19
LHR
-
ONT
32h 39m
2 stops
£649United Airlines
Wed, 19 Aug - Wed, 9 Sep
Iberia Logo
14:08 - 20:00
ONT
-
LGW
21h 52m
2 stops
Iberia Logo
11:30 - 23:46
LGW
-
ONT
20h 16m
2 stops
£675Iberia
Tue, 21 Apr - Sun, 3 May
British Airways Logo
10:59 - 15:15
ONT
-
LCY
20h 16m
2 stops
British Airways Logo
09:35 - 23:46
LCY
-
ONT
22h 11m
2 stops
£905British Airways
Tue, 21 Apr - Wed, 29 Apr
Iberia Logo
10:59 - 15:15
ONT
-
LCY
20h 16m
2 stops
Iberia Logo
19:15 - 20:54
LCY
-
ONT
33h 39m
2 stops
£922Iberia
Thu, 16 Apr - Mon, 20 Apr

Delta flights from Ontario to London

Our best Delta deals on Ontario to London flight tickets
Delta
15 Apr
ONT17:55Ontario
13h 40m
1 stop
LHR15:35London Heathrow
5 May
LHR09:55London Heathrow
19h 05m
2 stops
ONT21:00Ontario
£636
Delta
15 Apr
ONT06:00Ontario
17h 10m
2 stops
LHR07:10London Heathrow
5 May
LHR06:30London Heathrow
18h 45m
2 stops
ONT17:15Ontario
£639
Delta
23 Aug
ONT07:00Ontario
18h 15m
2 stops
LHR09:15London Heathrow
9 Sept
LHR06:30London Heathrow
18h 46m
2 stops
ONT17:16Ontario
£639

Air Canada flights from Ontario to London

Our best Air Canada deals on Ontario to London flight tickets
Air Canada
15 Apr
ONT05:10Ontario
17h 20m
2 stops
LHR06:30London Heathrow
21 May
LHR10:15London Heathrow
39h 13m
2 stops
ONT17:28Ontario
£642
Air Canada
15 Apr
ONT05:10Ontario
17h 20m
2 stops
LHR06:30London Heathrow
22 May
LHR09:30London Heathrow
43h 12m
2 stops
ONT20:42Ontario
£645
Air Canada
14 Apr
ONT06:00Ontario
16h 35m
2 stops
LHR06:35London Heathrow
21 Apr
LHR15:05London Heathrow
29h 15m
2 stops
ONT12:20Ontario
£646

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 28 March 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 15/4

17:55-15:35

1 stop13h 40m

London Heathrow

Tue 5/5

09:55-21:00

2 stops19h 05m

£636

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 15/4

06:00-07:10

2 stops17h 10m

London Heathrow

Tue 5/5

06:30-17:15

2 stops18h 45m

£639

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 15/4

05:10-06:30

2 stops17h 20m

London Heathrow

Thu 21/5

10:15-17:28

2 stops39h 13m

£642

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 23/8

05:45-11:35

1 stop21h 50m

London Heathrow

Tue 8/9

09:30-21:59

2 stops20h 29m

£644

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 15/4

05:10-06:30

2 stops17h 20m

London Heathrow

Fri 22/5

09:30-20:42

2 stops43h 12m

£645
Fastest return journey

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 29/4

10:59-07:55

1 stop12h 56m

London Heathrow

Fri 15/5

10:05-16:22

1 stop14h 17m

£648

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 19/8

07:00-06:55

2 stops15h 55m

London Heathrow

Wed 9/9

17:40-18:19

2 stops32h 39m

£649

OntarioLondon

ONT - LGW

ONTLGW

Ontario

Tue 21/4

14:08-20:00

2 stops21h 52m

London Gatwick

Sun 3/5

11:30-23:46

2 stops20h 16m

£675

OntarioLondon

ONT - LCY

ONTLCY

Ontario

Tue 21/4

10:59-15:15

2 stops20h 16m

London City

Wed 29/4

09:35-23:46

2 stops22h 11m

£905

OntarioLondon

ONT - LCY

ONTLCY

Ontario

Thu 16/4

10:59-15:15

2 stops20h 16m

London City

Mon 20/4

19:15-20:54

2 stops33h 39m

£922

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 March. Flight prices, which tend to average around £492, are often lower during this time because this is during the off-season. The month of April is another great option to travel to London, with average flight prices from Ontario averaging around £492.

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 £508. 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 £615.

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 £518. Flights at midday are often more expensive, with an average ticket price of £650.

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

  • 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
Luton
Gatwick
Maidstone
Slough
Southend-on-Sea
Ipswich
Wembley
Canterbury
Ilford
Guildford
Hayes
Chelmsford
Dover
Folkestone
Ramsgate
Chichester
Bedford
Worthing

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.

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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