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?

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

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 offers the lowest fares from Ontario to London?

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

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.

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 45% 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.

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.

$310 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.

12:01 pm - 4:00 pmONT Ontario-LHR London Heathrow

19h 59m2 stops San Francisco Kastrup Copenhagen

6:40 am - 8:30 amLHR London Heathrow-ONT Ontario

33h 50m3 stops Kastrup Copenhagen San Francisco Las Vegas Harry Reid Intl

$620Multiple Airlines

Mon, Nov 16 - Mon, Nov 23

12:01 pm - 4:00 pmONT Ontario-LHR London Heathrow

19h 59m2 stops San Francisco Kastrup Copenhagen

6:40 am - 12:24 amLHR London Heathrow-ONT Ontario

25h 44m2 stops Kastrup Copenhagen San Francisco

$623Multiple Airlines

Mon, Nov 16 - Sat, Nov 21

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

$751United Airlines

Tue, Mar 2 - Fri, Mar 5

1:42 pm - 8:35 pmONT Ontario-LHR London Heathrow

22h 53m2 stops Denver Intl Newark

5:30 pm - 8:01 pmLHR London Heathrow-ONT Ontario

34h 31m2 stops Frankfurt am Main San Francisco

$762United Airlines

Sun, Jan 10 - Tue, Jan 12

6:00 am - 12:20 pmONT Ontario-LHR London Heathrow

22h 20m1 stop Seattle/Tacoma Intl

2:45 pm - 10:39 pmLHR London Heathrow-ONT Ontario

15h 54m1 stop Seattle/Tacoma Intl

$798Alaska Airlines

Mon, Mar 1 - Sun, Mar 7

6:00 am - 12:20 pmONT Ontario-LHR London Heathrow

22h 20m1 stop Seattle/Tacoma Intl

2:45 pm - 10:39 pmLHR London Heathrow-ONT Ontario

15h 54m1 stop Seattle/Tacoma Intl

$802Alaska Airlines

Mon, Mar 1 - Sat, Mar 6

7:00 am - 6:25 amONT Ontario-LHR London Heathrow

15h 25m1 stop Atlanta Hartsfield-Jackson

11:45 am - 4:12 pmLHR London Heathrow-ONT Ontario

36h 27m2 stops Amsterdam Schiphol Salt Lake City

$874Delta

Sun, Jan 10 - Wed, Jan 13

7:00 am - 6:25 amONT Ontario-LHR London Heathrow

15h 25m1 stop Atlanta Hartsfield-Jackson

11:45 am - 4:12 pmLHR London Heathrow-ONT Ontario

36h 27m2 stops Amsterdam Schiphol Salt Lake City

$874Delta

Sun, Jan 10 - Tue, Jan 12

4:25 pm - 12:45 pmONT Ontario-LHR London Heathrow

12h 20m1 stop Phoenix Sky Harbor Intl

1:00 pm - 6:24 pmLHR London Heathrow-ONT Ontario

13h 24m1 stop Phoenix Sky Harbor Intl

$884British Airways

Tue, Mar 30 - Thu, Apr 8

4:25 pm - 12:45 pmONT Ontario-LHR London Heathrow

12h 20m1 stop Phoenix Sky Harbor Intl

1:00 pm - 6:24 pmLHR London Heathrow-ONT Ontario

13h 24m1 stop Phoenix Sky Harbor Intl

$884British Airways

Tue, Mar 30 - Fri, Apr 9

Cheap last minute flights

Enter your travel dates to find the best prices.

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

16h 52m1 stop Seattle/Tacoma Intl

2:45 pm - 11:42 pmLHR London Heathrow-ONT Ontario

15h 57m1 stop Seattle/Tacoma Intl

$1,015Alaska Airlines

Tue, Oct 20 - Thu, Oct 29

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

16h 52m1 stop Seattle/Tacoma Intl

2:45 pm - 11:42 pmLHR London Heathrow-ONT Ontario

15h 57m1 stop Seattle/Tacoma Intl

$1,015Alaska Airlines

Tue, Oct 20 - Fri, Oct 30

2:22 pm - 12:50 pmONT Ontario-LHR London Heathrow

14h 28m1 stop Dallas/Fort Worth

2:45 pm - 10:57 pmLHR London Heathrow-ONT Ontario

16h 12m1 stop Dallas/Fort Worth

$1,018Iberia

Tue, Oct 20 - Tue, Nov 10

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

$1,074British Airways

Fri, Oct 16 - Wed, Oct 21

7:00 am - 9:05 amONT Ontario-LHR London Heathrow

18h 05m1 stop Dallas/Fort Worth

6:00 am - 10:57 pmLHR London Heathrow-ONT Ontario

24h 57m2 stops Barcelona-El Prat Dallas/Fort Worth

$1,077Iberia

Tue, Oct 20 - Tue, Nov 10

1:52 pm - 11:10 amONT Ontario-LHR London Heathrow

13h 18m1 stop San Francisco

12:05 pm - 9:40 pmLHR London Heathrow-ONT Ontario

16h 35m1 stop Houston George Bush Intcntl

$1,136United Airlines

Tue, Oct 20 - Mon, Oct 26

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

12h 16m1 stop Denver Intl

10:35 am - 5:41 pmLHR London Heathrow-ONT Ontario

15h 06m1 stop San Francisco

$1,137United Airlines

Thu, Oct 15 - Tue, Oct 20

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

$1,179British Airways

Fri, Oct 16 - Fri, Oct 23

6:00 pm - 3:35 pmONT Ontario-LHR London Heathrow

13h 35m1 stop Seattle/Tacoma Intl

6:30 am - 8:25 pmLHR London Heathrow-ONT Ontario

21h 55m2 stops Amsterdam Schiphol Atlanta Hartsfield-Jackson

$1,885Delta

Sun, Oct 18 - Wed, Oct 21

7:07 am - 6:25 amONT Ontario-LHR London Heathrow

15h 18m1 stop Atlanta Hartsfield-Jackson

6:30 am - 8:25 pmLHR London Heathrow-ONT Ontario

21h 55m2 stops Amsterdam Schiphol Atlanta Hartsfield-Jackson

$1,885Delta

Mon, Oct 19 - Wed, Oct 21

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United Airlines flights from Ontario to London

Our best United Airlines deals on Ontario to London flight tickets

United Airlines

Jan 10

ONT1:42 pmOntario

22h 53m

2 stops

LHR8:35 pmLondon Heathrow

Jan 12

LHR5:30 pmLondon Heathrow

34h 31m

2 stops

ONT8:01 pmOntario

$762

United Airlines

Jan 9

ONT11:20 amOntario

26h 00m

2 stops

LHR9:20 pmLondon Heathrow

Jan 15

LHR1:30 pmLondon Heathrow

28h 27m

2 stops

ONT9:57 amOntario

$889

United Airlines

Jan 9

ONT3:59 pmOntario

31h 26m

1 stop

LHR7:25 amLondon Heathrow

Jan 14

LHR10:05 amLondon Heathrow

15h 30m

1 stop

ONT5:35 pmOntario

$906

Alaska Airlines flights from Ontario to London

Our best Alaska Airlines deals on Ontario to London flight tickets

Alaska Airlines

Jan 12

ONT11:36 amOntario

16h 44m

1 stop

LHR12:20 pmLondon Heathrow

Jan 19

LHR2:45 pmLondon Heathrow

27h 53m

1 stop

ONT10:38 amOntario

$808

Alaska Airlines

Jan 10

ONT11:36 amOntario

16h 44m

1 stop

LHR12:20 pmLondon Heathrow

Jan 12

LHR2:45 pmLondon Heathrow

15h 56m

1 stop

ONT10:41 pmOntario

$879

Alaska Airlines

Jan 9

ONT4:16 pmOntario

36h 04m

1 stop

LHR12:20 pmLondon Heathrow

Jan 12

LHR2:45 pmLondon Heathrow

15h 56m

1 stop

ONT10:41 pmOntario

$885

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Mon 11/16

12:01 pm-4:00 pm

2 stops19h 59m

London Heathrow

Mon 11/23

6:40 am-8:30 am

3 stops33h 50m

$620

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Mon 11/16

12:01 pm-4:00 pm

2 stops19h 59m

London Heathrow

Sat 11/21

6:40 am-12:24 am

2 stops25h 44m

$623

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

$751

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Sun 1/10

1:42 pm-8:35 pm

2 stops22h 53m

London Heathrow

Tue 1/12

5:30 pm-8:01 pm

2 stops34h 31m

$762

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Mon 3/1

6:00 am-12:20 pm

1 stop22h 20m

London Heathrow

Sun 3/7

2:45 pm-10:39 pm

1 stop15h 54m

$798

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Mon 3/1

6:00 am-12:20 pm

1 stop22h 20m

London Heathrow

Sat 3/6

2:45 pm-10:39 pm

1 stop15h 54m

$802

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Sun 1/10

7:00 am-6:25 am

1 stop15h 25m

London Heathrow

Wed 1/13

11:45 am-4:12 pm

2 stops36h 27m

$874

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Sun 1/10

7:00 am-6:25 am

1 stop15h 25m

London Heathrow

Tue 1/12

11:45 am-4:12 pm

2 stops36h 27m

$874

Quickest round-trip

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Tue 3/30

4:25 pm-12:45 pm

1 stop12h 20m

London Heathrow

Thu 4/8

1:00 pm-6:24 pm

1 stop13h 24m

$884

OntarioLondon

ONT Ontario - LHR London Heathrow

ONTLHR

Ontario

Tue 3/30

4:25 pm-12:45 pm

1 stop12h 20m

London Heathrow

Fri 4/9

1:00 pm-6:24 pm

1 stop13h 24m

$884

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 $739.

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 $941. If your travel schedule is flexible, try to avoid departing on a Saturday because tickets tend to average around $1,045. 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 $821 when looking at flights departing at noon. Flights to London are more costly in the afternoon, with an average ticket price of $1,005. 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 36% 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	$310
Fastest flight time	12h 00m
Direct flights	None

The best one-way flight to London from Ontario in the past 72 hours is $310. The best round-trip flight deal from Ontario to London found on momondo in the last 72 hours is $620.

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 46% 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 7.5 695 reviews	Search Virgin Atlantic flights
British Airways	PriceFrom $615	Free Cancellation	Rating 6.7 8,261 reviews	Search British Airways flights
United Airlines	PriceFrom $703	Free Cancellation	Rating 7.4 10,364 reviews	Search United Airlines flights
Delta	PriceFrom $710	Free Cancellation	Rating 7.8 8,652 reviews	Search Delta flights
Alaska Airlines	PriceFrom $806	Free Cancellation	Rating 7.9 13,070 reviews	Search Alaska Airlines flights

Hounslow

Gatwick

Croydon

Hayes

Milton Keynes

Luton

Stansted

Dover

Kingston upon Thames

Wembley

Richmond

Watford

Worthing

Harrow

Slough

Hook

Ilford

Canterbury

Dunstable

Eastbourne

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 $310

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 2/14. 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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United Airlines flights from Ontario to London

Our best United Airlines deals on Ontario to London flight tickets

Alaska Airlines flights from Ontario to London

Our best Alaska Airlines 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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