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Cheap flights from Ontario to London from £275

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 2/6. 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.
KLM Logo
11:55 - 15:35
ONT
-
LHR
19h 40m
1 stop
KLM Logo
06:30 - 16:14
LHR
-
ONT
17h 44m
2 stops
£662KLM
Sun, 23 Aug - Tue, 8 Sep
Virgin Atlantic Logo
13:35 - 12:10
ONT
-
LHR
14h 35m
1 stop
Virgin Atlantic Logo
09:55 - 23:34
LHR
-
ONT
21h 39m
2 stops
£663Virgin Atlantic
Wed, 13 May - Wed, 20 May
Delta Logo
06:00 - 07:10
ONT
-
LHR
17h 10m
2 stops
Delta Logo
06:30 - 18:01
LHR
-
ONT
19h 31m
2 stops
£665Delta
Sun, 23 Aug - Tue, 8 Sep
Virgin Atlantic Logo
09:55 - 13:15
ONT
-
LHR
19h 20m
2 stops
Virgin Atlantic Logo
11:45 - 22:40
LHR
-
ONT
18h 55m
2 stops
£666Virgin Atlantic
Mon, 10 Aug - Wed, 19 Aug
Delta Logo
13:00 - 10:00
ONT
-
LHR
13h 00m
1 stop
Delta Logo
06:15 - 16:14
LHR
-
ONT
17h 59m
2 stops
£667Delta
Mon, 10 Aug - Fri, 21 Aug
Air Canada Logo
05:00 - 10:00
ONT
-
LHR
21h 00m
2 stops
Air Canada Logo
10:15 - 20:52
LHR
-
ONT
42h 37m
2 stops
£669Air Canada
Mon, 10 Aug - Wed, 19 Aug
United Airlines Logo
13:50 - 11:10
ONT
-
LHR
13h 20m
1 stop
United Airlines Logo
09:30 - 21:59
LHR
-
ONT
20h 29m
2 stops
£671United Airlines
Mon, 3 Aug - Thu, 20 Aug
British Airways Logo
10:59 - 08:05
ONT
-
LHR
13h 06m
1 stop
British Airways Logo
10:05 - 16:22
LHR
-
ONT
14h 17m
1 stop
£672British Airways
Mon, 11 May - Tue, 19 May
British Airways Logo
10:59 - 08:05
ONT
-
LHR
13h 06m
1 stop
British Airways Logo
10:05 - 16:22
LHR
-
ONT
14h 17m
1 stop
£673British Airways
Tue, 12 May - Tue, 19 May
United Airlines Logo
19:13 - 06:45
ONT
-
LHR
27h 32m
2 stops
United Airlines Logo
09:30 - 21:59
LHR
-
ONT
20h 29m
2 stops
£674United Airlines
Sat, 22 Aug - Tue, 8 Sep

United Airlines flights from Ontario to London

Our best United Airlines deals on Ontario to London flight tickets
United Airlines
3 Aug
ONT13:50Ontario
13h 20m
1 stop
LHR11:10London Heathrow
20 Aug
LHR09:30London Heathrow
20h 29m
2 stops
ONT21:59Ontario
£671
United Airlines
22 Aug
ONT19:13Ontario
27h 32m
2 stops
LHR06:45London Heathrow
8 Sept
LHR09:30London Heathrow
20h 29m
2 stops
ONT21:59Ontario
£674
United Airlines
22 Aug
ONT19:13Ontario
28h 12m
1 stop
LHR07:25London Heathrow
8 Sept
LHR09:30London Heathrow
20h 29m
2 stops
ONT21:59Ontario
£674

Delta flights from Ontario to London

Our best Delta deals on Ontario to London flight tickets
Delta
23 Aug
ONT06:00Ontario
17h 10m
2 stops
LHR07:10London Heathrow
8 Sept
LHR06:30London Heathrow
19h 31m
2 stops
ONT18:01Ontario
£665
Delta
10 Aug
ONT13:00Ontario
13h 00m
1 stop
LHR10:00London Heathrow
20 Aug
LHR06:15London Heathrow
17h 59m
2 stops
ONT16:14Ontario
£667
Delta
20 Jul
ONT13:00Ontario
13h 00m
1 stop
LHR10:00London Heathrow
20 Aug
LHR10:55London Heathrow
13h 19m
1 stop
ONT16:14Ontario
£683

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 26 April 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

Sun 23/8

11:55-15:35

1 stop19h 40m

London Heathrow

Tue 8/9

06:30-16:14

2 stops17h 44m

£662

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 13/5

13:35-12:10

1 stop14h 35m

London Heathrow

Wed 20/5

09:55-23:34

2 stops21h 39m

£663

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 23/8

06:00-07:10

2 stops17h 10m

London Heathrow

Tue 8/9

06:30-18:01

2 stops19h 31m

£665

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 10/8

09:55-13:15

2 stops19h 20m

London Heathrow

Wed 19/8

11:45-22:40

2 stops18h 55m

£666

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 10/8

13:00-10:00

1 stop13h 00m

London Heathrow

Fri 21/8

06:15-16:14

2 stops17h 59m

£667

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 10/8

05:00-10:00

2 stops21h 00m

London Heathrow

Wed 19/8

10:15-20:52

2 stops42h 37m

£669

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 3/8

13:50-11:10

1 stop13h 20m

London Heathrow

Thu 20/8

09:30-21:59

2 stops20h 29m

£671
Fastest return journey

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 11/5

10:59-08:05

1 stop13h 06m

London Heathrow

Tue 19/5

10:05-16:22

1 stop14h 17m

£672

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 12/5

10:59-08:05

1 stop13h 06m

London Heathrow

Tue 19/5

10:05-16:22

1 stop14h 17m

£673

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 22/8

19:13-06:45

2 stops27h 32m

London Heathrow

Tue 8/9

09:30-21:59

2 stops20h 29m

£674

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 £426, are often lower during this time because this is during the off-season. The month of September is another great option to travel to London, with average flight prices from Ontario averaging around £449.

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 £500. 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 £621.

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 £535. Flights in the evening are often more expensive, with an average ticket price of £591.

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

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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