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.

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 Iberia 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 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 has the shortest connection time from Ontario to London?

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

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 December 2025, there are 7 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.

$247 Cheap Flights from Ontario to London in 2025/26

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 $675 to $791. The lowest price recently found on this route was $624.

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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.

6:00 am - 7:10 am

ONT

LHR

17h 10m2 stops

7:40 am - 10:36 pm

LHR

ONT

21h 56m2 stops

$624Multiple Airlines

Thu, Mar 5 - Thu, Mar 12

10:58 am - 11:40 am

ONT

LHR

16h 42m1 stop

6:00 am - 10:49 pm

LHR

ONT

24h 49m2 stops

$628Iberia

Tue, Feb 10 - Tue, Feb 17

7:30 am - 10:30 am

ONT

LHR

19h 00m1 stop

6:30 am - 9:04 pm

LHR

ONT

21h 34m2 stops

$630Delta

Thu, Mar 5 - Thu, Mar 12

1:15 pm - 11:40 am

ONT

LHR

14h 25m1 stop

6:30 am - 5:12 pm

LHR

ONT

17h 42m2 stops

$631KLM

Thu, Mar 5 - Thu, Mar 12

6:00 am - 10:10 am

ONT

LHR

20h 10m2 stops

7:30 am - 9:58 pm

LHR

ONT

22h 28m2 stops

$632Multiple Airlines

Sun, Jan 25 - Sun, Feb 1

6:00 am - 8:45 am

ONT

LHR

18h 45m2 stops

6:30 am - 9:04 pm

LHR

ONT

21h 34m2 stops

$635Delta

Thu, Mar 5 - Thu, Mar 12

6:00 am - 11:40 am

ONT

LHR

21h 40m2 stops

6:30 am - 9:05 pm

LHR

ONT

22h 35m2 stops

$636Delta

Fri, Jan 23 - Thu, Feb 5

1:50 pm - 9:40 am

ONT

LHR

12h 50m1 stop

6:30 am - 10:57 pm

LHR

ONT

23h 27m2 stops

$641United Airlines

Sun, Mar 15 - Tue, Mar 24

1:22 am - 2:25 pm

ONT

LCY

29h 03m2 stops

3:30 pm - 11:32 pm

LCY

ONT

40h 02m2 stops

$1,600British Airways

Sat, Jun 6 - Wed, Jun 17

6:35 am - 1:40 pm

ONT

LCY

23h 05m2 stops

3:30 pm - 11:32 pm

LCY

ONT

40h 02m2 stops

$1,601British Airways

Thu, Jun 11 - Wed, Jun 17

Air Canada flights from Ontario to London

Our best Air Canada deals on Ontario to London flight tickets

Air Canada

Mar 15

ONT5:15 amOntario

18h 55m

2 stops

LHR7:10 amLondon Heathrow

Mar 23

LHR3:00 pmLondon Heathrow

28h 49m

2 stops

ONT12:49 pmOntario

$639

Find similar

Air Canada

Mar 15

ONT5:15 amOntario

18h 55m

2 stops

LHR7:10 amLondon Heathrow

Mar 24

LHR11:10 amLondon Heathrow

40h 40m

2 stops

ONT8:50 pmOntario

$645

Find similar

Air Canada

Mar 16

ONT5:15 amOntario

20h 15m

2 stops

LHR8:30 amLondon Heathrow

Mar 26

LHR11:10 amLondon Heathrow

56h 38m

2 stops

ONT12:48 pmOntario

$692

Find similar

United Airlines flights from Ontario to London

Our best United Airlines deals on Ontario to London flight tickets

United Airlines

Mar 15

ONT1:50 pmOntario

12h 50m

1 stop

LHR9:40 amLondon Heathrow

Mar 24

LHR6:30 amLondon Heathrow

23h 27m

2 stops

ONT10:57 pmOntario

$641

Find similar

United Airlines

Mar 20

ONT5:15 amOntario

23h 05m

2 stops

LHR11:20 amLondon Heathrow

Mar 25

LHR10:05 amLondon Heathrow

14h 36m

1 stop

ONT5:41 pmOntario

$665

Find similar

United Airlines

Jan 20

ONT1:24 pmOntario

12h 16m

1 stop

LHR9:40 amLondon Heathrow

Jan 27

LHR9:30 amLondon Heathrow

20h 28m

2 stops

ONT9:58 pmOntario

$670

Find similar

Fly from

Fly to

Route

Depart

Return

Price

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Thu 3/5

6:00 am-7:10 am

2 stops17h 10m

London Heathrow

Thu 3/12

7:40 am-10:36 pm

2 stops21h 56m

$624

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 2/10

10:58 am-11:40 am

1 stop16h 42m

London Heathrow

Tue 2/17

6:00 am-10:49 pm

2 stops24h 49m

$628

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Thu 3/5

7:30 am-10:30 am

1 stop19h 00m

London Heathrow

Thu 3/12

6:30 am-9:04 pm

2 stops21h 34m

$630

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Thu 3/5

1:15 pm-11:40 am

1 stop14h 25m

London Heathrow

Thu 3/12

6:30 am-5:12 pm

2 stops17h 42m

$631

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 1/25

6:00 am-10:10 am

2 stops20h 10m

London Heathrow

Sun 2/1

7:30 am-9:58 pm

2 stops22h 28m

$632

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Thu 3/5

6:00 am-8:45 am

2 stops18h 45m

London Heathrow

Thu 3/12

6:30 am-9:04 pm

2 stops21h 34m

$635

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 1/23

6:00 am-11:40 am

2 stops21h 40m

London Heathrow

Thu 2/5

6:30 am-9:05 pm

2 stops22h 35m

$636

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 3/15

1:50 pm-9:40 am

1 stop12h 50m

London Heathrow

Tue 3/24

6:30 am-10:57 pm

2 stops23h 27m

$641

OntarioLondon

ONT - LCY

ONTLCY

Ontario

Sat 6/6

1:22 am-2:25 pm

2 stops29h 03m

London City

Wed 6/17

3:30 pm-11:32 pm

2 stops40h 02m

$1,600

OntarioLondon

ONT - LCY

ONTLCY

Ontario

Thu 6/11

6:35 am-1:40 pm

2 stops23h 05m

London City

Wed 6/17

3:30 pm-11:32 pm

2 stops40h 02m

$1,601

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 February. Flight prices, which tend to average around $657, 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 $750. If your travel schedule is flexible, try to avoid departing on a Saturday because tickets tend to average around $843. 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 $765 when looking at flights departing at noon. Flights to London are more costly in the evening, with an average ticket price of $815. 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 $828 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 $606 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 16m
Direct flights	None

The fastest flight from Ontario to London takes 12h 16m

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 16m.
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 December 2025, there are 7 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 28% of all bookings. The subsequent popular airlines are British Airways at 24%, Delta at 19%, and American Airlines at 15%.

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 $469	Free Cancellation	Rating 7.5 677 reviews	Search Virgin Atlantic flights
Delta	PriceFrom $570	Free Cancellation	Rating 7.9 8,019 reviews	Search Delta flights
KLM	PriceFrom $580	Free Cancellation	Rating 7.7 1,435 reviews	Search KLM flights
Iberia	PriceFrom $615	Free Cancellation	Rating 7.0 3,059 reviews	Search Iberia flights
American Airlines	PriceFrom $624	Free Cancellation	Rating 7.2 11,072 reviews	Search American Airlines flights
British Airways	PriceFrom $647	Free Cancellation	Rating 6.7 7,616 reviews	Search British Airways flights
United Airlines	PriceFrom $665	Free Cancellation	Rating 7.4 9,113 reviews	Search United Airlines flights

Gatwick

Hounslow

Milton Keynes

Dover

Luton

Slough

Guildford

Hayes

Dartford

Crawley

Brentwood

Watford

Wembley

Cobham

Folkestone

Romford

Richmond

Uxbridge

Chelmsford

Stansted

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.