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

Alaska Airlines, United Airlines, and Iberia are the most popular carriers operating from Ontario to London

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 airlines fly to London?

British Airways, United Airlines and American 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 48% 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 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 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 April 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.

$372 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 $1,054 to $756. The lowest price recently found on this route was $891.

1 adult

0 bags

Discover deals from 900+ travel sites with momondo.

Save money when you book flights with momondo

Big names and deals

Search 100s of travel sites to compare prices.

Filter for what you want

Free Wi-Fi? Stopover? Instantly customize your results.

Trusted and free

We’re completely free to use - no hidden charges or fees.

Price Alerts

Not ready to book? to track prices.

Search flight deals

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.

10:25 am - 12:50 pm

ONT

LHR

18h 25m

1 stop

6:15 am - 6:57 pm

LHR

ONT

20h 42m

2 stops

$891Iberia

Mon, Oct 5 - Tue, Oct 20

11:55 am - 3:35 pm

ONT

LHR

19h 40m

1 stop

6:30 am - 4:14 pm

LHR

ONT

17h 44m

2 stops

$896KLM

Sun, Aug 23 - Tue, Sep 8

6:00 am - 11:20 am

ONT

LHR

21h 20m

2 stops

6:30 am - 9:56 pm

LHR

ONT

23h 26m

2 stops

$900Delta

Mon, Aug 3 - Thu, Aug 20

9:55 am - 1:15 pm

ONT

LHR

19h 20m

2 stops

6:30 am - 4:14 pm

LHR

ONT

17h 44m

2 stops

$901Virgin Atlantic

Mon, Aug 10 - Wed, Aug 19

1:00 pm - 10:00 am

ONT

LHR

13h 00m

1 stop

6:15 am - 4:14 pm

LHR

ONT

17h 59m

2 stops

$903Delta

Mon, Aug 10 - Fri, Aug 21

5:00 am - 10:00 am

ONT

LHR

21h 00m

2 stops

10:15 am - 8:52 pm

LHR

ONT

42h 37m

2 stops

$905Air Canada

Mon, Aug 10 - Wed, Aug 19

1:18 pm - 9:40 am

ONT

LHR

12h 22m

1 stop

7:30 am - 6:11 pm

LHR

ONT

18h 41m

2 stops

$907United Airlines

Wed, Aug 19 - Tue, Sep 8

10:59 am - 8:05 am

ONT

LHR

13h 06m

1 stop

10:05 am - 4:22 pm

LHR

ONT

14h 17m

1 stop

$910British Airways

Tue, May 12 - Tue, May 19

5:00 am - 9:00 am

ONT

LHR

20h 00m

2 stops

9:30 am - 9:59 pm

LHR

ONT

20h 29m

2 stops

$911United Airlines

Sun, Aug 23 - Tue, Sep 8

10:29 am - 11:30 am

ONT

LCY

17h 01m

2 stops

7:00 am - 9:11 pm

LCY

ONT

22h 11m

3 stops

$1,273British Airways

Sun, Aug 9 - Wed, Aug 19

KLM flights from Ontario to London

Our best KLM deals on Ontario to London flight tickets

KLM

Aug 23

ONT11:55 amOntario

19h 40m

1 stop

LHR3:35 pmLondon Heathrow

Sep 8

LHR6:30 amLondon Heathrow

17h 44m

2 stops

ONT4:14 pmOntario

$896

KLM

Oct 19

ONT1:00 pmOntario

13h 00m

1 stop

LHR10:00 amLondon Heathrow

Oct 27

LHR10:00 amLondon Heathrow

14h 17m

1 stop

ONT5:17 pmOntario

$924

KLM

May 11

ONT1:35 pmOntario

18h 00m

1 stop

LHR3:35 pmLondon Heathrow

May 22

LHR11:40 amLondon Heathrow

18h 54m

1 stop

ONT10:34 pmOntario

$925

Delta flights from Ontario to London

Our best Delta deals on Ontario to London flight tickets

Delta

Aug 3

ONT6:00 amOntario

21h 20m

2 stops

LHR11:20 amLondon Heathrow

Aug 20

LHR6:30 amLondon Heathrow

23h 26m

2 stops

ONT9:56 pmOntario

$900

Delta

Aug 10

ONT1:00 pmOntario

13h 00m

1 stop

LHR10:00 amLondon Heathrow

Aug 21

LHR6:15 amLondon Heathrow

17h 59m

2 stops

ONT4:14 pmOntario

$903

Delta

Aug 10

ONT9:55 amOntario

16h 05m

1 stop

LHR10:00 amLondon Heathrow

Aug 18

LHR5:35 pmLondon Heathrow

30h 39m

2 stops

ONT4:14 pmOntario

$916

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 10/5

10:25 am-12:50 pm

1 stop18h 25m

London Heathrow

Tue 10/20

6:15 am-6:57 pm

2 stops20h 42m

$891

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 8/23

11:55 am-3:35 pm

1 stop19h 40m

London Heathrow

Tue 9/8

6:30 am-4:14 pm

2 stops17h 44m

$896

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 8/3

6:00 am-11:20 am

2 stops21h 20m

London Heathrow

Thu 8/20

6:30 am-9:56 pm

2 stops23h 26m

$900

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 8/10

9:55 am-1:15 pm

2 stops19h 20m

London Heathrow

Wed 8/19

6:30 am-4:14 pm

2 stops17h 44m

$901

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 8/10

1:00 pm-10:00 am

1 stop13h 00m

London Heathrow

Fri 8/21

6:15 am-4:14 pm

2 stops17h 59m

$903

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 8/10

5:00 am-10:00 am

2 stops21h 00m

London Heathrow

Wed 8/19

10:15 am-8:52 pm

2 stops42h 37m

$905

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 8/19

1:18 pm-9:40 am

1 stop12h 22m

London Heathrow

Tue 9/8

7:30 am-6:11 pm

2 stops18h 41m

$907

Quickest round-trip

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 5/12

10:59 am-8:05 am

1 stop13h 06m

London Heathrow

Tue 5/19

10:05 am-4:22 pm

1 stop14h 17m

$910

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 8/23

5:00 am-9:00 am

2 stops20h 00m

London Heathrow

Tue 9/8

9:30 am-9:59 pm

2 stops20h 29m

$911

OntarioLondon

ONT - LCY

ONTLCY

Ontario

Sun 8/9

10:29 am-11:30 am

2 stops17h 01m

London City

Wed 8/19

7:00 am-9:11 pm

3 stops22h 11m

$1,273

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 $743. If your travel schedule is flexible, try to avoid departing on a Saturday because tickets tend to average around $857. 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 $729 when looking at flights departing at noon. Flights to London are more costly in the evening, with an average ticket price of $808. Departure times in the evening 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 31% 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.

Search flight deals

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 April 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 47% of all bookings. The subsequent popular airlines are British Airways at 36% and Delta at 17%.

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 8,465 reviews	Search Delta flights
KLM	PriceFrom $580	Free Cancellation	Rating 7.8 1,508 reviews	Search KLM flights
American Airlines	PriceFrom $624	Free Cancellation	Rating 7.1 11,671 reviews	Search American Airlines flights
British Airways	PriceFrom $624	Free Cancellation	Rating 6.7 7,916 reviews	Search British Airways flights
United Airlines	PriceFrom $662	Free Cancellation	Rating 7.4 9,666 reviews	Search United Airlines flights

Hounslow

Gatwick

Milton Keynes

Dover

Luton

Hayes

Crawley

Slough

Wembley

Stansted

Watford

Croydon

Uxbridge

Brentwood

Dartford

Cobham

Folkestone

Romford

Harrow

Guildford

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.

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.

Start using Trips

Find my bookings

Get notified when prices go down

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

1 adult

Wed 5/27

Wed 6/3

Email me momondo's favorite deals

By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to the United Kingdom

Nearby airports

Airlines

Cabin classes

Other United Kingdom destinations

Other flights from Ontario

Complete your trip

Feeling lucky

Fly into one of these airports located in London

London City Airport

London Gatwick Airport

London Heathrow Airport

London Luton Airport

London Southend Airport

London Stansted Airport

Cheap flights from Ontario to London from $372

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 6/2. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.

Big names and deals

Big names and deals

Filter for what you want

Filter for what you want

Trusted and free

Trusted and free

Price Alerts

Price Alerts

Find the cheapest flights from Ontario to London

Cheap round-trip flights

Cheap one-way flights

Cheap last minute flights

KLM flights from Ontario to London

Our best KLM deals on Ontario to London flight tickets

Delta flights from Ontario to London

Our best Delta deals on Ontario to London flight tickets

momondo Fare Finder

Use the filters below to find and compare flights from Ontario to London that are best for you.

See travel insights to London from

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

Complete your trip to London

Explore popular destinations other users love

According to popular flight searches on momondo this year