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 offers the lowest fares from Ontario to London?

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

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.

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 46% of people opting to fly with this airline when traveling to London. Keep in mind that there are 21 different airlines that fly to London on a routine basis, so you have a few additional options to choose from.

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.

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

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

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 June 2026, there are 5 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.

$184 Cheap Flights from Ontario to London in 2026

Q: What is the typical price of a round-trip flight between Ontario and London?

Prices are currently low for flights on this route. Typical prices usually range from $1,545 to $1,336. The lowest price recently found on this route was $822.

Discover deals from 900+ travel sites with momondo.

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.

2:22 pm - 2:25 pm

ONT

LHR

16h 03m

1 stop

11:30 am - 11:06 pm

LHR

ONT

19h 36m

2 stops

$822Multiple Airlines

Wed, Sep 16 - Tue, Oct 13

1:05 pm - 10:30 am

ONT

LHR

13h 25m

1 stop

12:55 pm - 8:09 pm

LHR

ONT

15h 14m

1 stop

$825British Airways

Wed, Sep 9 - Fri, Sep 11

5:00 am - 6:30 am

ONT

LHR

17h 30m

2 stops

11:30 am - 11:06 pm

LHR

ONT

19h 36m

2 stops

$826Multiple Airlines

Wed, Sep 16 - Tue, Oct 13

2:14 pm - 3:05 pm

ONT

LHR

16h 51m

1 stop

5:00 pm - 11:42 pm

LHR

ONT

14h 42m

1 stop

$842Alaska Airlines

Wed, Oct 7 - Sun, Oct 11

12:12 pm - 3:05 pm

ONT

LHR

18h 53m

1 stop

5:00 pm - 1:19 pm

LHR

ONT

28h 19m

1 stop

$848Alaska Airlines

Sun, Sep 27 - Sun, Oct 4

7:05 am - 9:25 am

ONT

LGW

18h 20m

2 stops

10:25 am - 10:40 pm

LGW

ONT

20h 15m

2 stops

$927Delta

Wed, Sep 23 - Mon, Sep 28

1:00 pm - 4:40 pm

ONT

LCY

19h 40m

2 stops

9:20 am - 10:40 pm

LCY

ONT

21h 20m

2 stops

$944Delta

Wed, Sep 23 - Mon, Sep 28

7:00 am - 8:20 am

ONT

LGW

17h 20m

2 stops

9:25 am - 8:01 pm

LGW

ONT

18h 36m

2 stops

$998SWISS

Sat, Aug 22 - Fri, Sep 4

10:29 am - 1:10 pm

ONT

LCY

18h 41m

2 stops

9:50 am - 10:59 pm

LCY

ONT

21h 09m

2 stops

$1,129Iberia

Wed, Aug 26 - Fri, Sep 4

10:25 am - 3:15 pm

ONT

LCY

20h 50m

2 stops

7:15 pm - 9:29 am

LCY

ONT

21h 14m

2 stops

$1,259Iberia

Sun, Oct 18 - Mon, Oct 26

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Alaska Airlines flights from Ontario to London

Our best Alaska Airlines deals on Ontario to London flight tickets

Alaska Airlines

Oct 7

ONT2:14 pmOntario

16h 51m

1 stop

LHR3:05 pmLondon Heathrow

Oct 11

LHR5:00 pmLondon Heathrow

14h 42m

1 stop

ONT11:42 pmOntario

$842

Alaska Airlines

Sep 27

ONT12:12 pmOntario

18h 53m

1 stop

LHR3:05 pmLondon Heathrow

Oct 4

LHR5:00 pmLondon Heathrow

28h 19m

1 stop

ONT1:19 pmOntario

$848

Alaska Airlines

Oct 20

ONT2:14 pmOntario

16h 51m

1 stop

LHR3:05 pmLondon Heathrow

Oct 27

LHR2:45 pmLondon Heathrow

15h 57m

1 stop

ONT11:42 pmOntario

$877

United Airlines flights from Ontario to London

Our best United Airlines deals on Ontario to London flight tickets

United Airlines

Sep 18

ONT7:00 amOntario

19h 40m

2 stops

LHR10:40 amLondon Heathrow

Sep 20

LHR7:30 amLondon Heathrow

22h 29m

2 stops

ONT9:59 pmOntario

$854

United Airlines

Dec 6

ONT6:02 amOntario

17h 28m

1 stop

LHR7:30 amLondon Heathrow

Dec 10

LHR9:30 amLondon Heathrow

19h 51m

2 stops

ONT9:21 pmOntario

$876

United Airlines

Dec 6

ONT5:00 amOntario

18h 55m

2 stops

LHR7:55 amLondon Heathrow

Dec 10

LHR7:30 amLondon Heathrow

20h 50m

2 stops

ONT8:20 pmOntario

$881

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 9/16

2:22 pm-2:25 pm

1 stop16h 03m

London Heathrow

Tue 10/13

11:30 am-11:06 pm

2 stops19h 36m

$822

Quickest round-trip

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 9/9

1:05 pm-10:30 am

1 stop13h 25m

London Heathrow

Fri 9/11

12:55 pm-8:09 pm

1 stop15h 14m

$825

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 9/16

5:00 am-6:30 am

2 stops17h 30m

London Heathrow

Tue 10/13

11:30 am-11:06 pm

2 stops19h 36m

$826

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 10/7

2:14 pm-3:05 pm

1 stop16h 51m

London Heathrow

Sun 10/11

5:00 pm-11:42 pm

1 stop14h 42m

$842

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 9/27

12:12 pm-3:05 pm

1 stop18h 53m

London Heathrow

Sun 10/4

5:00 pm-1:19 pm

1 stop28h 19m

$848

OntarioLondon

ONT - LGW

ONTLGW

Ontario

Wed 9/23

7:05 am-9:25 am

2 stops18h 20m

London Gatwick

Mon 9/28

10:25 am-10:40 pm

2 stops20h 15m

$927

OntarioLondon

ONT - LCY

ONTLCY

Ontario

Wed 9/23

1:00 pm-4:40 pm

2 stops19h 40m

London City

Mon 9/28

9:20 am-10:40 pm

2 stops21h 20m

$944

OntarioLondon

ONT - LGW

ONTLGW

Ontario

Sat 8/22

7:00 am-8:20 am

2 stops17h 20m

London Gatwick

Fri 9/4

9:25 am-8:01 pm

2 stops18h 36m

$998

OntarioLondon

ONT - LCY

ONTLCY

Ontario

Wed 8/26

10:29 am-1:10 pm

2 stops18h 41m

London City

Fri 9/4

9:50 am-10:59 pm

2 stops21h 09m

$1,129

OntarioLondon

ONT - LCY

ONTLCY

Ontario

Sun 10/18

10:25 am-3:15 pm

2 stops20h 50m

London City

Mon 10/26

7:15 pm-9:29 am

2 stops21h 14m

$1,259

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 typical price of a round-trip flight between Ontario and London?

What is the cheapest month to fly to London?

The cheapest month to fly to London from Ontario is in September. Flight prices, which tend to average around $251, are often lower during this time because this is during the off-season. The month of December is another great option to travel to London, with average flight prices from Ontario averaging around $282.

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 $772. If your travel schedule is flexible, try to avoid departing on a Saturday because tickets tend to average around $909. 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 $676 when looking at flights departing at noon. Flights to London are more costly in the afternoon, with an average ticket price of $856. Departure times in the afternoon fall within the peak daily travel times, which is why tickets can be more expensive.

Can stopping save me money on Ontario to London flights?

You could potentially save up to 45% on your flight if you consider stops on a Ontario to London flight.

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 22m
Direct flights	None

The fastest flight from Ontario to London takes 12h 22m

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

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Frequently asked questions about flying from Ontario to London

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 22m.
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 June 2026, there are 5 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 United Airlines, representing 51% of all bookings. The subsequent popular airlines are British Airways at 31% and Delta at 18%.

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 8,403 reviews	Search Delta flights
KLM	PriceFrom $580	Free Cancellation	Rating 7.8 1,529 reviews	Search KLM flights
American Airlines	PriceFrom $620	Free Cancellation	Rating 7.1 11,654 reviews	Search American Airlines flights
British Airways	PriceFrom $624	Free Cancellation	Rating 6.7 8,047 reviews	Search British Airways flights
United Airlines	PriceFrom $665	Free Cancellation	Rating 7.4 9,819 reviews	Search United Airlines flights

Hounslow

Gatwick

Milton Keynes

Luton

Dover

Hayes

Crawley

Croydon

Wembley

Stansted

Harrow

Slough

Brentwood

Watford

Cobham

Guildford

Folkestone

Uxbridge

Romford

Chelmsford

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.

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Fly into one of these airports located in London

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London Stansted Airport

Cheap flights from Ontario to London from $184

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 8/29. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.

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Alaska Airlines flights from Ontario to London

Our best Alaska Airlines deals on Ontario to London flight tickets

United Airlines flights from Ontario to London

Our best United Airlines deals on Ontario to London flight tickets

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How to get the cheapest flight ticket from Ontario to London

What is the typical price of a round-trip flight between Ontario and London?

What is the cheapest month to fly to London?

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

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

Can stopping save me money on Ontario to London flights?

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

What airlines fly to London?

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

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

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

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

When to book flights from Ontario to London

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

Direct flights

Frequently asked questions about flying from Ontario to London

Best airlines flying from Ontario to London

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

Traveling to a place near London?

Why use momondo?

An easier way to manage your London 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.

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.

Find better results for your trip to the United Kingdom

Fly into one of these airports located in London

Airports listed have a maximum distance of 35.6 mi from London

Fly your favorite airline to London

Airlines are sorted and displayed according to clicks in the past 7 days on momondo

Cabin classes currently available on flights to London

List of cabin classes available on flights landing in London. Availability may vary depending on flight origin and airline.

Popular cities in the United Kingdom

Popular flights according to clicks in the last 7 days on momondo

Fly to other destinations from Ontario

According to popular flight searches on momondo this year

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