What is the cheapest airline that flies from Ontario to London?

British Airways, United Airlines, and Delta are the most popular carriers operating from Ontario to London

What airlines fly to London?

British Airways, Virgin Atlantic and United Airlines are the top three most popular airlines that fly to London from Ontario according to our data. British Airways is the first choice among our users, with 50% of people opting to fly with this airline when traveling to London. Keep in mind that there are 20 different airlines that fly to London on a routine basis, so you have a few additional options to choose from.

Which layover airport has the shortest travel time from Ontario to London?

Flights connecting via Denver (DEN) have the shortest average one-way travel time: 12h 40m.

Which layover airport has the shortest connection time from Ontario to London?

Salt Lake City (SLC) has the shortest average layover time for this route: 1h 13m.

Which airport is the most popular layover for flights between Ontario and London?

Dallas (DFW) was the most common stop: 25% of momondo users choosing 1-stop flights on this route connected there.

Which layover airport offers the lowest fares from Ontario to London?

Flights via Salt Lake City (SLC) offer the lowest average round-trip price of $624.

When did momondo last update prices for flights from Ontario Airport to London?

Prices for flights from Ontario Airport to London are updated daily.

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

As of January 2026, there are 6 operators available to choose from for flights from Ontario Airport to London.

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

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.

What documentation or ID do you need to fly to London?

The necessary travel and health documents for your London 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.

$374 Cheap Flights from Ontario to London in 2026

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Find the cheapest flights from Ontario to London

Round-trip

One-way

Last minute

Cheap round-trip flights

Enter your travel dates to find the best prices.

12:57 pm - 11:40 am

ONT

LHR

15h 43m

1 stop

8:25 pm - 4:28 pm

LHR

ONT

27h 03m

2 stops

$624KLM

Mon, Mar 9 - Mon, Mar 16

10:56 am - 6:50 am

ONT

LHR

12h 54m

1 stop

4:25 pm - 11:59 pm

LHR

ONT

15h 34m

1 stop

$625Iberia

Wed, Mar 25 - Wed, Apr 1

10:59 am - 8:05 am

ONT

LHR

13h 06m

1 stop

10:05 am - 4:22 pm

LHR

ONT

14h 17m

1 stop

$633British Airways

Tue, Apr 21 - Tue, Apr 28

3:30 pm - 8:10 pm

ONT

LHR

20h 40m

2 stops

6:30 am - 5:12 pm

LHR

ONT

17h 42m

2 stops

$636Delta

Tue, Mar 3 - Tue, Mar 10

3:19 pm - 12:15 pm

ONT

LHR

13h 56m

1 stop

10:05 am - 4:22 pm

LHR

ONT

14h 17m

1 stop

$637British Airways

Tue, Mar 24 - Wed, Apr 1

6:10 am - 7:25 am

ONT

LHR

17h 15m

1 stop

9:30 am - 9:59 pm

LHR

ONT

20h 29m

2 stops

$641United Airlines

Sat, Feb 21 - Sat, Feb 28

5:15 am - 5:55 am

ONT

LHR

16h 40m

2 stops

9:30 am - 10:36 pm

LHR

ONT

20h 06m

2 stops

$646United Airlines

Thu, Mar 5 - Thu, Mar 12

7:30 am - 9:25 am

ONT

LGW

17h 55m

2 stops

10:25 am - 10:37 pm

LGW

ONT

20h 12m

2 stops

$754Delta

Thu, Apr 23 - Mon, May 4

7:00 am - 8:50 am

ONT

LCY

17h 50m

2 stops

6:15 pm - 10:36 pm

LCY

ONT

35h 21m

2 stops

$899Multiple Airlines

Tue, Mar 3 - Tue, Mar 10

6:14 am - 10:55 am

ONT

LGW

20h 41m

2 stops

11:55 am - 10:44 pm

LGW

ONT

18h 49m

2 stops

$960Multiple Airlines

Wed, Feb 25 - Wed, Mar 4

United Airlines flights from Ontario to London

Our best United Airlines deals on Ontario to London flight tickets

United Airlines

Feb 21

ONT6:10 amOntario

17h 15m

1 stop

LHR7:25 amLondon Heathrow

Feb 28

LHR9:30 amLondon Heathrow

20h 29m

2 stops

ONT9:59 pmOntario

$641

United Airlines

Mar 5

ONT5:15 amOntario

16h 40m

2 stops

LHR5:55 amLondon Heathrow

Mar 12

LHR9:30 amLondon Heathrow

20h 06m

2 stops

ONT10:36 pmOntario

$646

United Airlines

Mar 18

ONT1:50 pmOntario

12h 50m

1 stop

LHR9:40 amLondon Heathrow

Mar 26

LHR11:35 amLondon Heathrow

16h 15m

1 stop

ONT8:50 pmOntario

$652

Delta flights from Ontario to London

Our best Delta deals on Ontario to London flight tickets

Delta

Mar 3

ONT3:30 pmOntario

20h 40m

2 stops

LHR8:10 pmLondon Heathrow

Mar 10

LHR6:30 amLondon Heathrow

17h 42m

2 stops

ONT5:12 pmOntario

$636

Delta

Apr 20

ONT6:00 amOntario

20h 00m

1 stop

LHR10:00 amLondon Heathrow

May 13

LHR6:15 amLondon Heathrow

20h 00m

2 stops

ONT6:15 pmOntario

$653

Delta

Feb 20

ONT1:10 pmOntario

12h 50m

1 stop

LHR10:00 amLondon Heathrow

Feb 26

LHR2:30 pmLondon Heathrow

16h 07m

1 stop

ONT10:37 pmOntario

$658

Fly from

Fly to

Route

Depart

Return

Price

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 3/9

12:57 pm-11:40 am

1 stop15h 43m

London Heathrow

Mon 3/16

8:25 pm-4:28 pm

2 stops27h 03m

$624

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 3/25

10:56 am-6:50 am

1 stop12h 54m

London Heathrow

Wed 4/1

4:25 pm-11:59 pm

1 stop15h 34m

$625

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 4/21

10:59 am-8:05 am

1 stop13h 06m

London Heathrow

Tue 4/28

10:05 am-4:22 pm

1 stop14h 17m

$633

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 3/3

3:30 pm-8:10 pm

2 stops20h 40m

London Heathrow

Tue 3/10

6:30 am-5:12 pm

2 stops17h 42m

$636

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 3/24

3:19 pm-12:15 pm

1 stop13h 56m

London Heathrow

Wed 4/1

10:05 am-4:22 pm

1 stop14h 17m

$637

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 2/21

6:10 am-7:25 am

1 stop17h 15m

London Heathrow

Sat 2/28

9:30 am-9:59 pm

2 stops20h 29m

$641

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Thu 3/5

5:15 am-5:55 am

2 stops16h 40m

London Heathrow

Thu 3/12

9:30 am-10:36 pm

2 stops20h 06m

$646

OntarioLondon

ONT - LGW

ONTLGW

Ontario

Thu 4/23

7:30 am-9:25 am

2 stops17h 55m

London Gatwick

Mon 5/4

10:25 am-10:37 pm

2 stops20h 12m

$754

OntarioLondon

ONT - LCY

ONTLCY

Ontario

Tue 3/3

7:00 am-8:50 am

2 stops17h 50m

London City

Tue 3/10

6:15 pm-10:36 pm

2 stops35h 21m

$899

OntarioLondon

ONT - LGW

ONTLGW

Ontario

Wed 2/25

6:14 am-10:55 am

2 stops20h 41m

London Gatwick

Wed 3/4

11:55 am-10:44 pm

2 stops18h 49m

$960

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first

How to get the cheapest flight ticket from Ontario to London

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

Prices

Airlines

Layovers

What is the cheapest month to fly to London?

The cheapest month to fly to London from Ontario is in February. Flight prices, which tend to average around $654, are often lower during this time because this is during the off-season. The month of October is another great option to travel to London, with average flight prices from Ontario averaging around $679.

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

The cheapest day to depart from Ontario to London is on a Wednesday. Travelers who choose to depart for London on a Wednesday will often find tickets for as low as $742. If your travel schedule is flexible, try to avoid departing on a Saturday because tickets tend to average around $833. These prices are subject to change though, so be sure to set up a Price Alert for flights to London.

What is the cheapest time of day to depart on your flight to London?

Flying to London from Ontario at noon is the least expensive time of day to depart. momondo users have found prices as low as $756 when looking at flights departing at noon. Flights to London are more costly in the evening, with an average ticket price of $806. Departure times in the evening fall within the peak daily travel times, which is why tickets can be more expensive.

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

You are more likely to see cheaper flights to London from Ontario when booking weeks ahead of your departure date. In general, you can expect to find flights to London for around $846 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to London from Ontario for as low as $607 on momondo.

When to book flights from Ontario to London

Are you open to changing your travel dates? Check out the ideal times to fly from Ontario to London according to our flight data. Find out which month and days have the cheapest flights.

Estimated round-trip price

Cheap Ontario to London (ONT to LON) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Ontario to London

Fastest flight time	12h 30m
Direct flights	None

The fastest flight from Ontario to London takes 12h 30m

There are no direct flights from Ontario to London. There are no popular flight routes from Ontario to London.

Search flight deals

How far is Ontario to London by plane?
The straight-line distance from Ontario to London is 5417.5 mi. A reasonable flight in good conditions will take 12h 30m.
When did momondo last update prices for flights from Ontario Airport to London?
Prices for flights from Ontario Airport to London are updated daily.
How many operators does momondo search for flights from Ontario Airport to London?
As of January 2026, there are 6 operators available to choose from for flights from Ontario Airport to London.
How old do you have to be to fly from Ontario Airport to London?
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.
What documentation or ID do you need to fly to London?
The necessary travel and health documents for your London 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?
momondo data reveals that the most frequently booked airline on the route from Ontario to London is British Airways, representing 29% of all bookings. The subsequent popular airlines are United Airlines at 26%, Delta at 18%, and Iberia at 14%.

Best airlines flying from Ontario to London

Compare and see reviews for airlines that fly from Ontario to London with momondo

Airline	Rating	Free Cancellation	Price
Delta	PriceFrom $570	Free Cancellation	Rating 7.9 8,113 reviews	Search Delta flights
KLM	PriceFrom $580	Free Cancellation	Rating 7.7 1,442 reviews	Search KLM flights
Iberia	PriceFrom $615	Free Cancellation	Rating 7.0 3,098 reviews	Search Iberia flights
British Airways	PriceFrom $624	Free Cancellation	Rating 6.7 7,700 reviews	Search British Airways flights
American Airlines	PriceFrom $624	Free Cancellation	Rating 7.2 11,189 reviews	Search American Airlines flights
United Airlines	PriceFrom $662	Free Cancellation	Rating 7.4 9,198 reviews	Search United Airlines flights

Gatwick

Hounslow

Milton Keynes

Luton

Dover

Slough

Guildford

Crawley

Wembley

Dartford

Hayes

Brentwood

Harrow

Watford

Cobham

Folkestone

Romford

Stansted

Croydon

Richmond

Why use momondo?

Why should I use momondo to find a flight deal from Ontario to London?

momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from Ontario to London. Millions of users trust and use momondo every year so you are in good hands.

Can I find flights from Ontario to London with flexible booking policies on momondo?

All flight searches from Ontario to London on momondo can be filtered to show those which offer 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 can track prices for Ontario to London flights and alert you when they change. Perform a search to set up the price alert. All that is required is a valid email address.