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

Flights via San Francisco (SFO) offer the lowest average round-trip price of $725.

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 31m.

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

Denver (DEN) has the shortest average layover time for this route: 1h 22m.

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

JetBlue, British Airways, and Virgin Atlantic 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 44% of people opting to fly with this airline when traveling to London. Keep in mind that there are 24 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?

Denver (DEN) was the most common stop: 40% of momondo users choosing 1-stop flights on this route connected there.

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 October 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.

$317 Cheap Flights from Ontario to London in 2026/27

Discover deals from 900+ travel sites with momondo.

Find the cheapest flights from Ontario to London

Round-trip

One-way

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Cheap round-trip flights

Enter your travel dates to find the best prices.

6:35 pm - 7:25 amONT Ontario-LHR London Heathrow

28h 50m1 stop San Francisco

6:50 am - 6:44 pmLHR London Heathrow-ONT Ontario

19h 54m2 stops Brussels Bruxelles-National Chicago O'Hare Intl

$752United Airlines

Tue, Mar 2 - Fri, Mar 5

1:00 pm - 10:15 amONT Ontario-LHR London Heathrow

37h 15m2 stops Denver Intl Houston George Bush Intcntl

6:50 am - 6:44 pmLHR London Heathrow-ONT Ontario

19h 54m2 stops Brussels Bruxelles-National Chicago O'Hare Intl

$767United Airlines

Tue, Mar 2 - Fri, Mar 5

6:30 am - 7:30 pmONT Ontario-LHR London Heathrow

29h 00m2 stops Denver Intl Reykjavik Keflavik Intl

12:15 pm - 11:51 pmLHR London Heathrow-ONT Ontario

19h 36m2 stops Reykjavik Keflavik Intl Denver Intl

$799Multiple Airlines

Wed, Nov 4 - Mon, Nov 9

6:25 am - 10:50 amONT Ontario-LHR London Heathrow

20h 25m2 stops Denver Intl Reykjavik Keflavik Intl

12:15 pm - 11:51 pmLHR London Heathrow-ONT Ontario

19h 36m2 stops Reykjavik Keflavik Intl Denver Intl

$800Multiple Airlines

Tue, Nov 10 - Tue, Nov 17

11:36 am - 12:20 pmONT Ontario-LHR London Heathrow

16h 44m1 stop Seattle/Tacoma Intl

2:45 pm - 10:41 pmLHR London Heathrow-ONT Ontario

15h 56m1 stop Seattle/Tacoma Intl

$802Alaska Airlines

Sun, Jan 10 - Fri, Jan 22

7:00 am - 12:20 pmONT Ontario-LHR London Heathrow

21h 20m1 stop Seattle/Tacoma Intl

2:45 pm - 10:41 pmLHR London Heathrow-ONT Ontario

15h 56m1 stop Seattle/Tacoma Intl

$802Alaska Airlines

Sun, Jan 17 - Wed, Jan 27

5:02 pm - 1:35 pmONT Ontario-LHR London Heathrow

13h 33m1 stop Phoenix Sky Harbor Intl

2:25 pm - 9:28 pmLHR London Heathrow-ONT Ontario

15h 03m1 stop Dallas/Fort Worth

$842British Airways

Wed, Mar 17 - Wed, Mar 31

5:02 pm - 1:35 pmONT Ontario-LHR London Heathrow

13h 33m1 stop Phoenix Sky Harbor Intl

2:35 pm - 10:07 pmLHR London Heathrow-ONT Ontario

14h 32m1 stop Phoenix Sky Harbor Intl

$842British Airways

Wed, Mar 17 - Mon, Mar 22

7:07 am - 7:50 amONT Ontario-LHR London Heathrow

17h 43m1 stop Atlanta Hartsfield-Jackson

6:30 am - 10:43 pmLHR London Heathrow-ONT Ontario

24h 13m2 stops Amsterdam Schiphol Seattle/Tacoma Intl

$902Delta

Mon, Oct 26 - Tue, Nov 3

1:35 pm - 10:00 amONT Ontario-LHR London Heathrow

13h 25m1 stop Salt Lake City

6:30 am - 5:16 pmLHR London Heathrow-ONT Ontario

18h 46m2 stops Amsterdam Schiphol Seattle/Tacoma Intl

$903Delta

Wed, Oct 28 - Thu, Nov 26

Cheap last minute flights

Enter your travel dates to find the best prices.

10:39 pm - 9:30 amONT Ontario-LHR London Heathrow

26h 51m1 stop New York John F Kennedy Intl

11:55 am - 10:12 pmLHR London Heathrow-ONT Ontario

18h 17m1 stop New York John F Kennedy Intl

$889JetBlue

Sun, Oct 4 - Tue, Oct 13

10:42 pm - 8:45 pmONT Ontario-LHR London Heathrow

14h 03m1 stop New York John F Kennedy Intl

8:15 am - 10:12 pmLHR London Heathrow-ONT Ontario

21h 57m1 stop New York John F Kennedy Intl

$891JetBlue

Tue, Oct 6 - Tue, Oct 13

9:45 am - 10:20 amONT Ontario-LHR London Heathrow

16h 35m2 stops Salt Lake City Minneapolis St Paul

11:45 am - 10:43 pmLHR London Heathrow-ONT Ontario

18h 58m2 stops Amsterdam Schiphol Seattle/Tacoma Intl

$1,062Delta

Tue, Oct 6 - Thu, Oct 15

1:24 pm - 9:40 amONT Ontario-LHR London Heathrow

12h 16m1 stop Denver Intl

11:05 am - 6:47 pmLHR London Heathrow-ONT Ontario

39h 42m2 stops Brussels Bruxelles-National Chicago O'Hare Intl

$1,070United Airlines

Sun, Oct 4 - Mon, Nov 2

1:24 pm - 9:40 amONT Ontario-LHR London Heathrow

12h 16m1 stop Denver Intl

4:15 pm - 10:51 pmLHR London Heathrow-ONT Ontario

14h 36m1 stop San Francisco

$1,086United Airlines

Wed, Oct 7 - Thu, Oct 15

2:13 pm - 3:05 pmONT Ontario-LHR London Heathrow

16h 52m1 stop Seattle/Tacoma Intl

5:00 pm - 11:42 pmLHR London Heathrow-ONT Ontario

14h 42m1 stop Seattle/Tacoma Intl

$1,086Alaska Airlines

Wed, Oct 7 - Thu, Oct 15

11:13 am - 3:05 pmONT Ontario-LHR London Heathrow

19h 52m1 stop Seattle/Tacoma Intl

2:45 pm - 11:06 pmLHR London Heathrow-ONT Ontario

16h 21m1 stop Seattle/Tacoma Intl

$1,087Alaska Airlines

Mon, Oct 5 - Thu, Nov 19

1:05 pm - 10:30 amONT Ontario-LHR London Heathrow

13h 25m1 stop Phoenix Sky Harbor Intl

10:05 am - 3:16 pmLHR London Heathrow-ONT Ontario

13h 11m1 stop Phoenix Sky Harbor Intl

$1,095British Airways

Tue, Oct 6 - Thu, Oct 15

1:05 pm - 10:30 amONT Ontario-LHR London Heathrow

13h 25m1 stop Phoenix Sky Harbor Intl

10:05 am - 3:24 pmLHR London Heathrow-ONT Ontario

13h 19m1 stop Phoenix Sky Harbor Intl

$1,096British Airways

Tue, Oct 6 - Tue, Oct 13

12:29 pm - 10:00 amONT Ontario-LHR London Heathrow

13h 31m1 stop Salt Lake City

11:40 am - 10:43 pmLHR London Heathrow-ONT Ontario

19h 03m1 stop Seattle/Tacoma Intl

$1,137Delta

Mon, Oct 5 - Sun, Oct 11

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Alaska Airlines flights from Ontario to London

Our best Alaska Airlines deals on Ontario to London flight tickets

Alaska Airlines

Jan 16

ONT4:16 pmOntario

36h 04m

1 stop

LHR12:20 pmLondon Heathrow

Jan 20

LHR2:45 pmLondon Heathrow

15h 56m

1 stop

ONT10:41 pmOntario

$813

Alaska Airlines

Jan 23

ONT4:16 pmOntario

36h 04m

1 stop

LHR12:20 pmLondon Heathrow

Jan 31

LHR2:45 pmLondon Heathrow

27h 53m

1 stop

ONT10:38 amOntario

$819

Alaska Airlines

Jan 6

ONT7:00 amOntario

21h 20m

1 stop

LHR12:20 pmLondon Heathrow

Jan 15

LHR2:45 pmLondon Heathrow

27h 53m

1 stop

ONT10:38 amOntario

$828

Iberia flights from Ontario to London

Our best Iberia deals on Ontario to London flight tickets

Iberia

Oct 26

ONT7:00 amOntario

18h 15m

1 stop

LHR8:15 amLondon Heathrow

Nov 3

LHR6:05 amLondon Heathrow

24h 52m

2 stops

ONT10:57 pmOntario

$899

Iberia

Nov 4

ONT7:00 amOntario

19h 00m

1 stop

LHR10:00 amLondon Heathrow

Nov 17

LHR8:25 amLondon Heathrow

22h 32m

2 stops

ONT10:57 pmOntario

$900

Iberia

Oct 6

ONT2:22 pmOntario

14h 28m

1 stop

LHR12:50 pmLondon Heathrow

Oct 15

LHR4:25 pmLondon Heathrow

15h 27m

1 stop

ONT11:52 pmOntario

$1,073

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Tue 3/2

6:35 pm-7:25 am

1 stop28h 50m

London Heathrow

Fri 3/5

6:50 am-6:44 pm

2 stops19h 54m

$752

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Tue 3/2

1:00 pm-10:15 am

2 stops37h 15m

London Heathrow

Fri 3/5

6:50 am-6:44 pm

2 stops19h 54m

$767

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Wed 11/4

6:30 am-7:30 pm

2 stops29h 00m

London Heathrow

Mon 11/9

12:15 pm-11:51 pm

2 stops19h 36m

$799

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Tue 11/10

6:25 am-10:50 am

2 stops20h 25m

London Heathrow

Tue 11/17

12:15 pm-11:51 pm

2 stops19h 36m

$800

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Sun 1/10

11:36 am-12:20 pm

1 stop16h 44m

London Heathrow

Fri 1/22

2:45 pm-10:41 pm

1 stop15h 56m

$802

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Sun 1/17

7:00 am-12:20 pm

1 stop21h 20m

London Heathrow

Wed 1/27

2:45 pm-10:41 pm

1 stop15h 56m

$802

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Wed 3/17

5:02 pm-1:35 pm

1 stop13h 33m

London Heathrow

Wed 3/31

2:25 pm-9:28 pm

1 stop15h 03m

$842

Quickest round-trip

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Wed 3/17

5:02 pm-1:35 pm

1 stop13h 33m

London Heathrow

Mon 3/22

2:35 pm-10:07 pm

1 stop14h 32m

$842

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Mon 10/26

7:07 am-7:50 am

1 stop17h 43m

London Heathrow

Tue 11/3

6:30 am-10:43 pm

2 stops24h 13m

$902

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Wed 10/28

1:35 pm-10:00 am

1 stop13h 25m

London Heathrow

Thu 11/26

6:30 am-5:16 pm

2 stops18h 46m

$903

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 January. Flight prices, which tend to average around $688, 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 $743.

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 $930. If your travel schedule is flexible, try to avoid departing on a Saturday because tickets tend to average around $1,033. 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 $820 when looking at flights departing at noon. Flights to London are more costly in the afternoon, with an average ticket price of $994. 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 56% 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

Best Price Found	$317
Fastest flight time	12h 00m
Direct flights	None

The best one-way flight to London from Ontario in the past 72 hours is $317. The best round-trip flight deal from Ontario to London found on momondo in the last 72 hours is $752.

The fastest flight from Ontario to London takes 12h 00m

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 00m.
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 October 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 28% and Virgin Atlantic at 25%.

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
Virgin Atlantic	PriceFrom $488	Free Cancellation	Rating 7.4 694 reviews	Search Virgin Atlantic flights
British Airways	PriceFrom $615	Free Cancellation	Rating 6.7 8,241 reviews	Search British Airways flights
United Airlines	PriceFrom $703	Free Cancellation	Rating 7.4 10,275 reviews	Search United Airlines flights
Delta	PriceFrom $710	Free Cancellation	Rating 7.8 8,619 reviews	Search Delta flights
Alaska Airlines	PriceFrom $806	Free Cancellation	Rating 7.9 13,004 reviews	Search Alaska Airlines flights

Hounslow

Gatwick

Croydon

Hayes

Luton

Dover

Wembley

Milton Keynes

Kingston upon Thames

Richmond

Stansted

Watford

Harrow

Cobham

Worthing

Eastbourne

Slough

Hook

Ilford

Canterbury

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

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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 $317

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 3/3. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.

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Alaska Airlines flights from Ontario to London

Our best Alaska Airlines deals on Ontario to London flight tickets

Iberia flights from Ontario to London

Our best Iberia deals on Ontario to London flight tickets

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See travel insights to London from

How to get the cheapest flight ticket from Ontario to 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

Best Price Found

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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