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Cheap flights from Ontario to London from $304

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 1/17. 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
6:00 am - 6:50 amONT-LHR
17h 50m1 stop
Iberia Logo
6:00 am - 10:48 pmLHR-ONT
23h 48m2 stops
$575Iberia
Find Deal
Tue, Mar 10 - Tue, Mar 17
Iberia Logo
10:58 am - 8:35 amONT-LHR
13h 37m1 stop
Iberia Logo
7:30 am - 10:48 pmLHR-ONT
23h 18m2 stops
$577Iberia
Find Deal
Wed, Jan 21 - Thu, Jan 29
British Airways Logo
10:58 am - 8:35 amONT-LHR
13h 37m1 stop
British Airways Logo
6:00 am - 6:45 pmLHR-ONT
20h 45m2 stops
$584British Airways
Find Deal
Tue, Jan 13 - Tue, Jan 20
British Airways Logo
10:56 am - 6:50 amONT-LHR
12h 54m1 stop
British Airways Logo
10:15 am - 6:42 pmLHR-ONT
15h 27m1 stop
$591British Airways
Find Deal
Tue, Mar 10 - Tue, Mar 17
British Airways Logo
4:45 pm - 1:15 pmONT-LHR
12h 30m1 stop
British Airways Logo
10:35 am - 6:39 pmLHR-ONT
16h 04m1 stop
$596British Airways
Find Deal
Mon, Feb 2 - Thu, Feb 19
Delta Logo
7:30 am - 10:30 amONT-LHR
19h 00m1 stop
Delta Logo
6:20 am - 9:05 pmLHR-ONT
22h 45m2 stops
$598Delta
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Wed, Jan 14 - Wed, Jan 21
Iberia Logo
7:16 am - 10:00 amONT-LHR
18h 44m1 stop
Iberia Logo
7:30 am - 10:48 pmLHR-ONT
23h 18m2 stops
$602Iberia
Find Deal
Fri, Jan 16 - Thu, Jan 22
Delta Logo
3:30 pm - 8:10 pmONT-LHR
20h 40m2 stops
Delta Logo
6:20 am - 10:51 pmLHR-ONT
24h 31m2 stops
$603Delta
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Tue, Jan 13 - Tue, Jan 20
Delta Logo
6:00 am - 9:00 amONT-LHR
19h 00m2 stops
Delta Logo
8:40 am - 9:05 pmLHR-ONT
20h 25m2 stops
$604Delta
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Wed, Jan 21 - Thu, Jan 29
Iberia Logo
10:58 am - 8:35 amONT-LHR
13h 37m1 stop
Iberia Logo
3:00 pm - 10:48 pmLHR-ONT
15h 48m1 stop
$605Iberia
Find Deal
Wed, Jan 21 - Tue, Feb 3

Air Canada flights from Ontario to London Heathrow Airport

Our best Air Canada deals on Ontario to London Heathrow Airport flight tickets
Air Canada
Jan 5
ONT1:40 pmOntario
56h 50m
2 stops
LHR6:30 amLondon Heathrow
Jan 20
LHR1:25 pmLondon Heathrow
31h 22m
2 stops
ONT12:47 pmOntario
$656
Find similar
Air Canada
Feb 3
ONT5:05 amOntario
17h 25m
2 stops
LHR6:30 amLondon Heathrow
Feb 28
LHR1:25 pmLondon Heathrow
39h 25m
2 stops
ONT8:50 pmOntario
$675
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KLM flights from Ontario to London Heathrow Airport

Our best KLM deals on Ontario to London Heathrow Airport flight tickets
KLM
Jan 21
ONT7:30 amOntario
19h 00m
1 stop
LHR10:30 amLondon Heathrow
Jan 29
LHR12:30 pmLondon Heathrow
16h 35m
1 stop
ONT9:05 pmOntario
$605
Find similar
KLM
May 5
ONT12:00 pmOntario
17h 30m
1 stop
LHR1:30 pmLondon Heathrow
May 21
LHR10:55 amLondon Heathrow
19h 14m
1 stop
ONT10:09 pmOntario
$620
Find similar
KLM
May 5
ONT1:00 pmOntario
12h 50m
1 stop
LHR9:50 amLondon Heathrow
May 15
LHR11:20 amLondon Heathrow
13h 56m
1 stop
ONT5:16 pmOntario
$621
Find similar

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 December 3, 2025.
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

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 3/10

6:00 am-6:50 am

1 stop17h 50m

London Heathrow

Tue 3/17

6:00 am-10:48 pm

2 stops23h 48m

$575

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 1/21

10:58 am-8:35 am

1 stop13h 37m

London Heathrow

Thu 1/29

7:30 am-10:48 pm

2 stops23h 18m

$577

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 1/13

10:58 am-8:35 am

1 stop13h 37m

London Heathrow

Tue 1/20

6:00 am-6:45 pm

2 stops20h 45m

$584

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 3/10

10:56 am-6:50 am

1 stop12h 54m

London Heathrow

Tue 3/17

10:15 am-6:42 pm

1 stop15h 27m

$591

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 2/2

4:45 pm-1:15 pm

1 stop12h 30m

London Heathrow

Thu 2/19

10:35 am-6:39 pm

1 stop16h 04m

$596

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 1/14

7:30 am-10:30 am

1 stop19h 00m

London Heathrow

Wed 1/21

6:20 am-9:05 pm

2 stops22h 45m

$598

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 1/16

7:16 am-10:00 am

1 stop18h 44m

London Heathrow

Thu 1/22

7:30 am-10:48 pm

2 stops23h 18m

$602

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 1/13

3:30 pm-8:10 pm

2 stops20h 40m

London Heathrow

Tue 1/20

6:20 am-10:51 pm

2 stops24h 31m

$603

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 1/21

6:00 am-9:00 am

2 stops19h 00m

London Heathrow

Thu 1/29

8:40 am-9:05 pm

2 stops20h 25m

$604

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 1/21

10:58 am-8:35 am

1 stop13h 37m

London Heathrow

Tue 2/3

3:00 pm-10:48 pm

1 stop15h 48m

$605

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 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 $644. 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 $689.

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 $766. The most expensive day to fly to London Heathrow Airport is Saturday, with ticket prices averaging around $869.

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 $773. 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 evening are often more expensive with an average ticket price of $822.

How far in advance should I book a flight to London Heathrow Airport?

You are more likely to see cheaper flights to London Heathrow Airport from Ontario when booking weeks ahead of your departure date. In general, you can expect to find flights to London Heathrow Airport for around $834 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to London Heathrow Airport from Ontario for as low as $606 on momondo.

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 06m

Direct flights

None
The fastest flight from Ontario to London Heathrow Airport takes 12h 06m
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

  • 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 09m 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
8,011 reviews
Search Delta flights
KLMPriceFrom $580Free CancellationRating
7.7
1,428 reviews
Search KLM flights
IberiaPriceFrom $615Free CancellationRating
7.0
3,039 reviews
Search Iberia flights
American AirlinesPriceFrom $624Free CancellationRating
7.2
11,044 reviews
Search American Airlines flights
British AirwaysPriceFrom $653Free CancellationRating
6.7
7,557 reviews
Search British Airways flights
United AirlinesPriceFrom $665Free CancellationRating
7.4
9,065 reviews
Search United Airlines flights

Traveling to a place near London?

Book flights to London if you plan to visit one of these locations
Gatwick
Hounslow
Milton Keynes
Dover
Luton
Slough
Guildford
Hayes
Dartford
Stratford-upon-Avon
Crawley
Brentwood
Salisbury
Wembley
Romford
Watford
Ilford
Cobham
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

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.
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