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Cheap flights from Ontario to London from $293

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 7/29. 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

Discover deals from 900+ travel sites with momondo.

Find the cheapest flights from Ontario to London

Cheap round-trip flights

Enter your travel dates to find the best prices.
British Airways Logo
2:22 pm - 12:50 pm
ONT
-
LHR
14h 28m
1 stop
British Airways Logo
2:45 pm - 11:06 pm
LHR
-
ONT
15h 21m
1 stop
$822British Airways
Sun, Oct 18 - Thu, Oct 29
Multiple Airlines Logo
6:00 am - 10:00 am
ONT
-
LHR
20h 00m
2 stops
Multiple Airlines Logo
8:20 am - 9:08 pm
LHR
-
ONT
19h 48m
1 stop
$825Multiple Airlines
Sun, Oct 18 - Thu, Oct 29
Multiple Airlines Logo
10:47 am - 12:00 pm
ONT
-
LHR
17h 13m
1 stop
Multiple Airlines Logo
2:45 pm - 11:55 pm
LHR
-
ONT
17h 10m
1 stop
$826Multiple Airlines
Tue, Nov 17 - Tue, Dec 15
British Airways Logo
1:05 pm - 10:30 am
ONT
-
LHR
13h 25m
1 stop
British Airways Logo
10:15 am - 6:57 pm
LHR
-
ONT
15h 42m
1 stop
$827British Airways
Sun, Oct 4 - Sat, Oct 31
Alaska Airlines Logo
12:12 pm - 3:05 pm
ONT
-
LHR
18h 53m
1 stop
Alaska Airlines Logo
5:00 pm - 11:45 pm
LHR
-
ONT
14h 45m
1 stop
$828Alaska Airlines
Sun, Sep 20 - Sat, Oct 3
Multiple Airlines Logo
7:00 am - 9:15 am
ONT
-
LHR
18h 15m
2 stops
Multiple Airlines Logo
2:45 pm - 10:19 pm
LHR
-
ONT
15h 34m
1 stop
$834Multiple Airlines
Tue, Nov 17 - Tue, Dec 15
Multiple Airlines Logo
12:00 pm - 12:20 pm
ONT
-
LHR
16h 20m
1 stop
Multiple Airlines Logo
2:45 pm - 10:23 pm
LHR
-
ONT
15h 38m
1 stop
$838Multiple Airlines
Wed, Nov 18 - Mon, Nov 30
Multiple Airlines Logo
12:00 pm - 12:20 pm
ONT
-
LHR
16h 20m
1 stop
Multiple Airlines Logo
2:45 pm - 10:23 pm
LHR
-
ONT
15h 38m
1 stop
$842Multiple Airlines
Wed, Nov 18 - Mon, Nov 30
Multiple Airlines Logo
12:00 pm - 12:20 pm
ONT
-
LHR
16h 20m
1 stop
Multiple Airlines Logo
2:45 pm - 10:23 pm
LHR
-
ONT
15h 38m
1 stop
$843Multiple Airlines
Wed, Nov 18 - Mon, Nov 30
Multiple Airlines Logo
1:05 pm - 10:30 am
ONT
-
LHR
13h 25m
1 stop
Multiple Airlines Logo
5:00 pm - 11:45 pm
LHR
-
ONT
14h 45m
1 stop
$844Multiple Airlines
Sun, Oct 4 - Mon, Oct 12

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Delta flights from Ontario to London Heathrow Airport

Our best Delta deals on Ontario to London Heathrow Airport flight tickets
Delta
Aug 31
ONT5:05 pmOntario
19h 05m
2 stops
LHR8:10 pmLondon Heathrow
Sep 16
LHR6:30 amLondon Heathrow
18h 50m
2 stops
ONT5:20 pmOntario
$899
Delta
Sep 23
ONT1:04 pmOntario
12h 56m
1 stop
LHR10:00 amLondon Heathrow
Sep 28
LHR9:55 amLondon Heathrow
20h 45m
2 stops
ONT10:40 pmOntario
$914
Delta
Sep 23
ONT7:05 amOntario
19h 15m
2 stops
LHR10:20 amLondon Heathrow
Sep 28
LHR11:45 amLondon Heathrow
18h 55m
2 stops
ONT10:40 pmOntario
$919

Air Canada flights from Ontario to London Heathrow Airport

Our best Air Canada deals on Ontario to London Heathrow Airport flight tickets
Air Canada
Oct 18
ONT6:00 amOntario
47h 20m
2 stops
LHR1:20 pmLondon Heathrow
Oct 29
LHR2:30 pmLondon Heathrow
37h 26m
2 stops
ONT8:56 pmOntario
$869
Air Canada
Sep 1
ONT5:00 amOntario
21h 00m
2 stops
LHR10:00 amLondon Heathrow
Sep 16
LHR9:30 amLondon Heathrow
43h 23m
2 stops
ONT8:53 pmOntario
$907
Air Canada
Aug 3
ONT5:00 amOntario
22h 50m
2 stops
LHR11:50 amLondon Heathrow
Aug 20
LHR3:00 pmLondon Heathrow
35h 11m
2 stops
ONT6:11 pmOntario
$908

momondo Fare Finder

 
Customize 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 832,500 searches. Data last updated June 22, 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 round-trip

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 10/18

2:22 pm-12:50 pm

1 stop14h 28m

London Heathrow

Thu 10/29

2:45 pm-11:06 pm

1 stop15h 21m

$822

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 10/18

6:00 am-10:00 am

2 stops20h 00m

London Heathrow

Thu 10/29

8:20 am-9:08 pm

1 stop19h 48m

$825

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 11/17

10:47 am-12:00 pm

1 stop17h 13m

London Heathrow

Tue 12/15

2:45 pm-11:55 pm

1 stop17h 10m

$826

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 10/4

1:05 pm-10:30 am

1 stop13h 25m

London Heathrow

Sat 10/31

10:15 am-6:57 pm

1 stop15h 42m

$827

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 9/20

12:12 pm-3:05 pm

1 stop18h 53m

London Heathrow

Sat 10/3

5:00 pm-11:45 pm

1 stop14h 45m

$828

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 11/17

7:00 am-9:15 am

2 stops18h 15m

London Heathrow

Tue 12/15

2:45 pm-10:19 pm

1 stop15h 34m

$834

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 11/18

12:00 pm-12:20 pm

1 stop16h 20m

London Heathrow

Mon 11/30

2:45 pm-10:23 pm

1 stop15h 38m

$838

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 11/18

12:00 pm-12:20 pm

1 stop16h 20m

London Heathrow

Mon 11/30

2:45 pm-10:23 pm

1 stop15h 38m

$842

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 11/18

12:00 pm-12:20 pm

1 stop16h 20m

London Heathrow

Mon 11/30

2:45 pm-10:23 pm

1 stop15h 38m

$843
Quickest round-trip

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 10/4

1:05 pm-10:30 am

1 stop13h 25m

London Heathrow

Mon 10/12

5:00 pm-11:45 pm

1 stop14h 45m

$844

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
1
2

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?

The month of November is, on average, the cheapest month to fly to London Heathrow Airport from Ontario, with most prices found around $624. If you’re not able to fly to London Heathrow Airport in November, then September is your next best option. Flight prices from Ontario to London Heathrow Airport during September average around $640.

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

Our data shows that Wednesday is the least expensive day to fly to London Heathrow Airport. Tickets to fly out on this day can be as low as $795. The most expensive day to fly to London Heathrow Airport is Saturday, with ticket prices averaging around $940.

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 noon. momondo users have found flights departing from Ontario to London Heathrow Airport at noon for as low as $660. Keep in mind that these prices may fluctuate based on what airline you choose and the time of year you plan to travel. Flights in the afternoon are often more expensive with an average ticket price of $921.

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 round-trip 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 16m

Direct flights

None
The fastest flight from Ontario to London Heathrow Airport takes 12h 16m
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?

    The straight-line distance from Ontario to London Heathrow is 5408.1 mi. Typically, this will take 12h 16m by plane in normal conditions.

  • 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 are updated daily.

  • How many operators does momondo search for flights from Ontario Airport to London Heathrow Airport?

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

    The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Ontario Airport to London Heathrow Airport.

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

    The necessary travel and health documents for your London Heathrow Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

  • What is the most popular airline from Ontario to London Heathrow Airport?

Best airlines flying from Ontario to London Heathrow Airport

Compare and see reviews for airlines that fly from Ontario to London Heathrow Airport with momondo
Airline
Rating
Free Cancellation
Price
DeltaPriceFrom $570Free CancellationRating
7.8
8,421 reviews
Search Delta flights
KLMPriceFrom $580Free CancellationRating
7.8
1,530 reviews
Search KLM flights
American AirlinesPriceFrom $620Free CancellationRating
7.1
11,740 reviews
Search American Airlines flights
British AirwaysPriceFrom $624Free CancellationRating
6.7
8,064 reviews
Search British Airways flights
United AirlinesPriceFrom $665Free CancellationRating
7.4
9,874 reviews
Search United Airlines flights

Traveling to a place near London?

Book flights to London if you plan to visit one of these locations
Hounslow
Gatwick
Milton Keynes
Luton
Hayes
Dover
Crawley
Croydon
Wembley
Stansted
Stratford-upon-Avon
Harrow
Slough
Watford
Cobham
Brentwood
Guildford
Ilford
Folkestone
Uxbridge

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?

momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from Ontario to London.

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

Yes momondo offers price alerts on flights to London from Ontario. After performing a search on this page you should be able to see the price alert set up feature. Simply provide a valid email address and momondo will instantly alert you when prices change.

An easier way to manage your London Heathrow Airport trip

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Wed 7/22
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