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Cheap flights from Ontario to London from $256

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 11/3. 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.
KLM Logo
7:05 am - 7:50 amONT-LHR
16h 45m1 stop
KLM Logo
6:30 am - 5:09 pmLHR-ONT
18h 39m2 stops
$643KLM
Find Deal
Tue, Nov 18 - Tue, Nov 25
KLM Logo
7:05 am - 7:50 amONT-LHR
16h 45m1 stop
KLM Logo
6:30 am - 5:09 pmLHR-ONT
18h 39m2 stops
$652KLM
Find Deal
Tue, Nov 18 - Tue, Nov 25
Delta Logo
6:00 am - 7:05 amONT-LHR
17h 05m2 stops
Delta Logo
6:30 am - 7:39 pmLHR-ONT
21h 09m2 stops
$656Delta
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Wed, Nov 19 - Tue, Dec 9
British Airways Logo
10:47 am - 11:40 amONT-LHR
16h 53m1 stop
British Airways Logo
11:55 am - 10:28 pmLHR-ONT
18h 33m1 stop
$672British Airways
Find Deal
Tue, Nov 11 - Tue, Dec 9
British Airways Logo
4:47 pm - 1:15 pmONT-LHR
12h 28m1 stop
British Airways Logo
3:00 pm - 10:29 pmLHR-ONT
15h 29m1 stop
$673British Airways
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Tue, Nov 11 - Tue, Nov 18
Delta Logo
11:48 am - 10:30 amONT-LHR
14h 42m1 stop
Delta Logo
2:45 pm - 10:55 pmLHR-ONT
16h 10m1 stop
$680Delta
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Sun, Nov 16 - Tue, Nov 25
United Airlines Logo
6:38 pm - 7:25 amONT-LHR
28h 47m1 stop
United Airlines Logo
10:05 am - 5:37 pmLHR-ONT
15h 32m1 stop
$685United Airlines
Find Deal
Sat, Nov 22 - Tue, Dec 9
Iberia Logo
6:10 am - 10:00 amONT-LHR
19h 50m1 stop
Iberia Logo
7:40 pm - 11:53 amLHR-ONT
24h 13m2 stops
$694Iberia
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Tue, Nov 4 - Wed, Nov 19
United Airlines Logo
10:40 am - 7:25 amONT-LHR
13h 45m1 stop
United Airlines Logo
10:35 am - 6:00 pmLHR-ONT
15h 25m1 stop
$704United Airlines
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Wed, Mar 25 - Wed, Apr 1
Iberia Logo
10:57 am - 6:50 amONT-LHR
12h 53m1 stop
Iberia Logo
4:30 pm - 11:54 amLHR-ONT
27h 24m1 stop
$708Iberia
Find Deal
Mon, Oct 27 - Fri, Nov 7

United Airlines flights from Ontario to London Heathrow Airport

Our best United Airlines deals on Ontario to London Heathrow Airport flight tickets
United Airlines
Nov 22
ONT6:38 pmOntario
28h 47m
1 stop
LHR7:25 amLondon Heathrow
Dec 9
LHR10:05 amLondon Heathrow
15h 32m
1 stop
ONT5:37 pmOntario
$685
Find similar
United Airlines
Mar 25
ONT10:40 amOntario
13h 45m
1 stop
LHR7:25 amLondon Heathrow
Apr 1
LHR10:35 amLondon Heathrow
15h 25m
1 stop
ONT6:00 pmOntario
$704
Find similar
United Airlines
Jan 9
ONT6:39 pmOntario
55h 01m
2 stops
LHR9:40 amLondon Heathrow
Jan 18
LHR8:30 amLondon Heathrow
21h 28m
2 stops
ONT9:58 pmOntario
$711
Find similar

British Airways flights from Ontario to London Heathrow Airport

Our best British Airways deals on Ontario to London Heathrow Airport flight tickets
British Airways
Nov 11
ONT10:47 amOntario
16h 53m
1 stop
LHR11:40 amLondon Heathrow
Dec 9
LHR11:55 amLondon Heathrow
18h 33m
1 stop
ONT10:28 pmOntario
$672
Find similar
British Airways
Nov 11
ONT4:47 pmOntario
12h 28m
1 stop
LHR1:15 pmLondon Heathrow
Nov 18
LHR3:00 pmLondon Heathrow
15h 29m
1 stop
ONT10:29 pmOntario
$673
Find similar
British Airways
Feb 3
ONT4:49 pmOntario
12h 26m
1 stop
LHR1:15 pmLondon Heathrow
Feb 10
LHR3:00 pmLondon Heathrow
15h 49m
1 stop
ONT10:49 pmOntario
$681
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 October 6, 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 11/18

7:05 am-7:50 am

1 stop16h 45m

London Heathrow

Tue 11/25

6:30 am-5:09 pm

2 stops18h 39m

$643

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 11/18

7:05 am-7:50 am

1 stop16h 45m

London Heathrow

Tue 11/25

6:30 am-5:09 pm

2 stops18h 39m

$652

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 11/19

6:00 am-7:05 am

2 stops17h 05m

London Heathrow

Tue 12/9

6:30 am-7:39 pm

2 stops21h 09m

$656

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 11/11

10:47 am-11:40 am

1 stop16h 53m

London Heathrow

Tue 12/9

11:55 am-10:28 pm

1 stop18h 33m

$672

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 11/11

4:47 pm-1:15 pm

1 stop12h 28m

London Heathrow

Tue 11/18

3:00 pm-10:29 pm

1 stop15h 29m

$673

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 11/16

11:48 am-10:30 am

1 stop14h 42m

London Heathrow

Tue 11/25

2:45 pm-10:55 pm

1 stop16h 10m

$680

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 11/22

6:38 pm-7:25 am

1 stop28h 47m

London Heathrow

Tue 12/9

10:05 am-5:37 pm

1 stop15h 32m

$685

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 11/4

6:10 am-10:00 am

1 stop19h 50m

London Heathrow

Wed 11/19

7:40 pm-11:53 am

2 stops24h 13m

$694

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 3/25

10:40 am-7:25 am

1 stop13h 45m

London Heathrow

Wed 4/1

10:35 am-6:00 pm

1 stop15h 25m

$704

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 10/27

10:57 am-6:50 am

1 stop12h 53m

London Heathrow

Fri 11/7

4:30 pm-11:54 am

1 stop27h 24m

$708

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 March is, on average, the cheapest month to fly to London Heathrow Airport from Ontario, with most prices found around $663. If you’re not able to fly to London Heathrow Airport in March, 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 $772. The most expensive day to fly to London Heathrow Airport is Saturday, with ticket prices averaging around $895.

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 $776. 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 morning are often more expensive with an average ticket price of $1,321.

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 $862 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

Direct flights

None
There are no direct flights from Ontario to London Heathrow Airport. There are no popular flight routes from Ontario to London Heathrow Airport.
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  • 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 01m 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
Virgin AtlanticPriceFrom $469Free CancellationRating
7.4
666 reviews
Search Virgin Atlantic flights
DeltaPriceFrom $572Free CancellationRating
7.9
7,967 reviews
Search Delta flights
KLMPriceFrom $580Free CancellationRating
7.8
1,394 reviews
Search KLM flights
IberiaPriceFrom $615Free CancellationRating
7.0
2,973 reviews
Search Iberia flights
American AirlinesPriceFrom $653Free CancellationRating
7.2
11,040 reviews
Search American Airlines flights
British AirwaysPriceFrom $662Free CancellationRating
6.7
7,430 reviews
Search British Airways flights
United AirlinesPriceFrom $677Free CancellationRating
7.4
8,957 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
Luton
Dover
Slough
Guildford
Dartford
Hayes
Crawley
Chelmsford
Brentwood
Salisbury
Colchester
Ilford
Folkestone
Romford
Swindon
Stratford-upon-Avon
Cobham

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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