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Cheap flights from Ontario to London from $422

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 5/12. 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
2:08 pm - 2:25 pm
ONT
-
LHR
16h 17m
1 stop
Iberia Logo
6:10 am - 8:54 pm
LHR
-
ONT
22h 44m
2 stops
$793Iberia
Wed, Apr 15 - Tue, May 5
Delta Logo
5:55 pm - 3:35 pm
ONT
-
LHR
13h 40m
1 stop
Delta Logo
6:30 am - 6:36 pm
LHR
-
ONT
20h 06m
2 stops
$794Delta
Wed, May 6 - Wed, May 13
Delta Logo
1:29 pm - 1:15 pm
ONT
-
LHR
15h 46m
2 stops
Delta Logo
11:45 am - 10:37 pm
LHR
-
ONT
18h 52m
2 stops
$798Delta
Wed, Apr 15 - Tue, May 5
British Airways Logo
10:56 am - 7:55 am
ONT
-
LHR
12h 59m
1 stop
British Airways Logo
10:05 am - 4:22 pm
LHR
-
ONT
14h 17m
1 stop
$801British Airways
Wed, Apr 1 - Fri, Apr 24
British Airways Logo
10:56 am - 8:05 am
ONT
-
LHR
13h 09m
1 stop
British Airways Logo
10:05 am - 4:22 pm
LHR
-
ONT
14h 17m
1 stop
$804British Airways
Sun, Apr 5 - Tue, Apr 21
British Airways Logo
10:56 am - 7:55 am
ONT
-
LHR
12h 59m
1 stop
British Airways Logo
10:05 am - 4:22 pm
LHR
-
ONT
14h 17m
1 stop
$808British Airways
Wed, Apr 1 - Thu, Apr 9
British Airways Logo
10:56 am - 7:55 am
ONT
-
LHR
12h 59m
1 stop
British Airways Logo
10:05 am - 4:22 pm
LHR
-
ONT
14h 17m
1 stop
$810British Airways
Wed, Apr 1 - Wed, Apr 8
Air Canada Logo
1:34 pm - 6:35 am
ONT
-
LHR
33h 01m
2 stops
Air Canada Logo
2:05 pm - 8:36 pm
LHR
-
ONT
38h 31m
2 stops
$811Air Canada
Sat, Apr 25 - Fri, May 8
British Airways Logo
10:59 am - 8:05 am
ONT
-
LHR
13h 06m
1 stop
British Airways Logo
10:05 am - 4:22 pm
LHR
-
ONT
14h 17m
1 stop
$815British Airways
Tue, Apr 14 - Tue, Apr 21
British Airways Logo
10:56 am - 8:05 am
ONT
-
LHR
13h 09m
1 stop
British Airways Logo
10:05 am - 4:22 pm
LHR
-
ONT
14h 17m
1 stop
$816British Airways
Sun, Apr 5 - Tue, Apr 21

Iberia flights from Ontario to London Heathrow Airport

Our best Iberia deals on Ontario to London Heathrow Airport flight tickets
Iberia
Apr 15
ONT2:08 pmOntario
16h 17m
1 stop
LHR2:25 pmLondon Heathrow
May 5
LHR6:10 amLondon Heathrow
22h 44m
2 stops
ONT8:54 pmOntario
$793
Iberia
Apr 6
ONT2:39 pmOntario
13h 31m
1 stop
LHR12:10 pmLondon Heathrow
Apr 16
LHR4:25 pmLondon Heathrow
15h 21m
1 stop
ONT11:46 pmOntario
$870
Iberia
Mar 30
ONT2:39 pmOntario
13h 31m
1 stop
LHR12:10 pmLondon Heathrow
Apr 11
LHR4:25 pmLondon Heathrow
15h 21m
1 stop
ONT11:46 pmOntario
$923

United Airlines flights from Ontario to London Heathrow Airport

Our best United Airlines deals on Ontario to London Heathrow Airport flight tickets
United Airlines
Aug 25
ONT1:44 pmOntario
13h 26m
1 stop
LHR11:10 amLondon Heathrow
Sep 7
LHR3:30 pmLondon Heathrow
38h 29m
2 stops
ONT9:59 pmOntario
$843
United Airlines
Apr 15
ONT1:27 pmOntario
13h 43m
1 stop
LHR11:10 amLondon Heathrow
May 5
LHR9:30 amLondon Heathrow
20h 28m
2 stops
ONT9:58 pmOntario
$854
United Airlines
Apr 12
ONT5:10 amOntario
20h 30m
1 stop
LHR9:40 amLondon Heathrow
Apr 19
LHR7:30 amLondon Heathrow
22h 20m
2 stops
ONT9:50 pmOntario
$855

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 March 21, 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

Wed 4/15

2:08 pm-2:25 pm

1 stop16h 17m

London Heathrow

Tue 5/5

6:10 am-8:54 pm

2 stops22h 44m

$793

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 5/6

5:55 pm-3:35 pm

1 stop13h 40m

London Heathrow

Wed 5/13

6:30 am-6:36 pm

2 stops20h 06m

$794

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 4/15

1:29 pm-1:15 pm

2 stops15h 46m

London Heathrow

Tue 5/5

11:45 am-10:37 pm

2 stops18h 52m

$798
Quickest round-trip

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 4/1

10:56 am-7:55 am

1 stop12h 59m

London Heathrow

Fri 4/24

10:05 am-4:22 pm

1 stop14h 17m

$801

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 4/5

10:56 am-8:05 am

1 stop13h 09m

London Heathrow

Tue 4/21

10:05 am-4:22 pm

1 stop14h 17m

$804

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 4/1

10:56 am-7:55 am

1 stop12h 59m

London Heathrow

Thu 4/9

10:05 am-4:22 pm

1 stop14h 17m

$808

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 4/1

10:56 am-7:55 am

1 stop12h 59m

London Heathrow

Wed 4/8

10:05 am-4:22 pm

1 stop14h 17m

$810

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 4/25

1:34 pm-6:35 am

2 stops33h 01m

London Heathrow

Fri 5/8

2:05 pm-8:36 pm

2 stops38h 31m

$811

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 4/14

10:59 am-8:05 am

1 stop13h 06m

London Heathrow

Tue 4/21

10:05 am-4:22 pm

1 stop14h 17m

$815

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 4/5

10:56 am-8:05 am

1 stop13h 09m

London Heathrow

Tue 4/21

10:05 am-4:22 pm

1 stop14h 17m

$816

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 $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 $674.

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 $754. The most expensive day to fly to London Heathrow Airport is Saturday, with ticket prices averaging around $851.

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 $744. 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 $802.

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 56m

Direct flights

None
The fastest flight from Ontario to London Heathrow Airport takes 12h 56m
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 56m 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
8,312 reviews
Search Delta flights
KLMPriceFrom $580Free CancellationRating
7.8
1,475 reviews
Search KLM flights
American AirlinesPriceFrom $624Free CancellationRating
7.1
11,487 reviews
Search American Airlines flights
British AirwaysPriceFrom $624Free CancellationRating
6.7
7,805 reviews
Search British Airways flights
United AirlinesPriceFrom $662Free CancellationRating
7.4
9,452 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
Crawley
Stratford-upon-Avon
Wembley
Hayes
Dartford
Croydon
Harrow
Watford
Brentwood
Guildford
Stansted
Cobham
Folkestone
Romford

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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