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Cheap flights from Ontario to London from $448

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 10/4. 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 round-trip flights

Enter your travel dates to find the best prices.
Iberia Logo
10:25 am - 12:50 pm
ONT
-
LHR
18h 25m
1 stop
Iberia Logo
6:15 am - 9:08 pm
LHR
-
ONT
22h 53m
2 stops
$891Iberia
Tue, Oct 6 - Wed, Oct 14
Iberia Logo
2:22 pm - 2:25 pm
ONT
-
LHR
16h 03m
1 stop
Iberia Logo
7:50 am - 9:08 pm
LHR
-
ONT
21h 18m
2 stops
$895Iberia
Tue, Oct 6 - Thu, Oct 15
Delta Logo
10:00 pm - 6:25 am
ONT
-
LHR
24h 25m
1 stop
Delta Logo
6:30 am - 6:01 pm
LHR
-
ONT
19h 31m
2 stops
$896Delta
Mon, Aug 3 - Thu, Aug 20
Iberia Logo
2:22 pm - 5:15 pm
ONT
-
LHR
18h 53m
2 stops
Iberia Logo
3:45 pm - 11:48 am
LHR
-
ONT
27h 03m
2 stops
$899Iberia
Wed, Oct 21 - Wed, Oct 28
Delta Logo
11:48 am - 1:05 pm
ONT
-
LHR
17h 17m
2 stops
Delta Logo
6:30 am - 6:01 pm
LHR
-
ONT
19h 31m
2 stops
$900Delta
Mon, Aug 3 - Thu, Aug 20
Delta Logo
12:55 pm - 1:05 pm
ONT
-
LHR
16h 10m
2 stops
Delta Logo
6:30 am - 9:52 pm
LHR
-
ONT
23h 22m
2 stops
$901Delta
Mon, Aug 3 - Thu, Aug 20
Air Canada Logo
1:00 pm - 9:20 am
ONT
-
LHR
37h 20m
2 stops
Air Canada Logo
2:30 pm - 5:47 pm
LHR
-
ONT
35h 17m
2 stops
$902Air Canada
Sat, Oct 31 - Fri, Nov 13
United Airlines Logo
1:18 pm - 12:25 pm
ONT
-
LHR
15h 07m
1 stop
United Airlines Logo
7:30 am - 9:59 pm
LHR
-
ONT
22h 29m
2 stops
$907United Airlines
Mon, Aug 3 - Thu, Aug 20
Air Canada Logo
5:00 am - 9:20 am
ONT
-
LHR
45h 20m
2 stops
Air Canada Logo
11:10 am - 8:20 pm
LHR
-
ONT
41h 10m
2 stops
$910Air Canada
Sat, Oct 31 - Thu, Nov 12
United Airlines Logo
5:45 am - 8:40 pm
ONT
-
LHR
30h 55m
2 stops
United Airlines Logo
7:30 am - 9:59 pm
LHR
-
ONT
22h 29m
2 stops
$911United Airlines
Sat, Aug 22 - Tue, Sep 8

Delta flights from Ontario to London Heathrow Airport

Our best Delta deals on Ontario to London Heathrow Airport flight tickets
Delta
Aug 3
ONT10:00 pmOntario
24h 25m
1 stop
LHR6:25 amLondon Heathrow
Aug 20
LHR6:30 amLondon Heathrow
19h 31m
2 stops
ONT6:01 pmOntario
$896
Delta
Aug 3
ONT11:48 amOntario
17h 17m
2 stops
LHR1:05 pmLondon Heathrow
Aug 20
LHR6:30 amLondon Heathrow
19h 31m
2 stops
ONT6:01 pmOntario
$900
Delta
Aug 3
ONT12:55 pmOntario
16h 10m
2 stops
LHR1:05 pmLondon Heathrow
Aug 20
LHR6:30 amLondon Heathrow
23h 22m
2 stops
ONT9:52 pmOntario
$901

British Airways flights from Ontario to London Heathrow Airport

Our best British Airways deals on Ontario to London Heathrow Airport flight tickets
British Airways
Aug 5
ONT2:27 pmOntario
13h 43m
1 stop
LHR12:10 pmLondon Heathrow
Aug 19
LHR2:25 pmLondon Heathrow
16h 33m
1 stop
ONT10:58 pmOntario
$939
British Airways
Aug 22
ONT11:59 pmOntario
22h 21m
1 stop
LHR6:20 amLondon Heathrow
Sep 8
LHR10:05 amLondon Heathrow
19h 07m
1 stop
ONT9:12 pmOntario
$940
British Airways
Oct 22
ONT1:31 pmOntario
12h 59m
1 stop
LHR10:30 amLondon Heathrow
Oct 30
LHR2:25 pmLondon Heathrow
14h 10m
1 stop
ONT9:35 pmOntario
$960

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 May 4, 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

Tue 10/6

10:25 am-12:50 pm

1 stop18h 25m

London Heathrow

Wed 10/14

6:15 am-9:08 pm

2 stops22h 53m

$891

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 10/6

2:22 pm-2:25 pm

1 stop16h 03m

London Heathrow

Thu 10/15

7:50 am-9:08 pm

2 stops21h 18m

$895

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 8/3

10:00 pm-6:25 am

1 stop24h 25m

London Heathrow

Thu 8/20

6:30 am-6:01 pm

2 stops19h 31m

$896

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 10/21

2:22 pm-5:15 pm

2 stops18h 53m

London Heathrow

Wed 10/28

3:45 pm-11:48 am

2 stops27h 03m

$899
Quickest round-trip

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 8/3

11:48 am-1:05 pm

2 stops17h 17m

London Heathrow

Thu 8/20

6:30 am-6:01 pm

2 stops19h 31m

$900

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 8/3

12:55 pm-1:05 pm

2 stops16h 10m

London Heathrow

Thu 8/20

6:30 am-9:52 pm

2 stops23h 22m

$901

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 10/31

1:00 pm-9:20 am

2 stops37h 20m

London Heathrow

Fri 11/13

2:30 pm-5:47 pm

2 stops35h 17m

$902

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 8/3

1:18 pm-12:25 pm

1 stop15h 07m

London Heathrow

Thu 8/20

7:30 am-9:59 pm

2 stops22h 29m

$907

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 10/31

5:00 am-9:20 am

2 stops45h 20m

London Heathrow

Thu 11/12

11:10 am-8:20 pm

2 stops41h 10m

$910

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 8/22

5:45 am-8:40 pm

2 stops30h 55m

London Heathrow

Tue 9/8

7:30 am-9:59 pm

2 stops22h 29m

$911

Flights are sorted by cheapest round-trip 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?

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 $668.

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 $756. The most expensive day to fly to London Heathrow Airport is Saturday, with ticket prices averaging around $887.

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 $721. 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 $835.

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 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?

    The straight-line distance from Ontario to London Heathrow is 5408.1 mi. Typically, this will take 12h 22m 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
7.9
8,461 reviews
Search Delta flights
KLMPriceFrom $580Free CancellationRating
7.8
1,511 reviews
Search KLM flights
American AirlinesPriceFrom $620Free CancellationRating
7.1
11,673 reviews
Search American Airlines flights
British AirwaysPriceFrom $624Free CancellationRating
6.7
7,943 reviews
Search British Airways flights
United AirlinesPriceFrom $662Free CancellationRating
7.4
9,680 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
Dover
Luton
Hayes
Stratford-upon-Avon
Crawley
Slough
Wembley
Stansted
Watford
Croydon
Uxbridge
Brentwood
Dartford
Cobham
Folkestone
Romford
Harrow

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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