How long is the flight from Ontario to London?

Delta, KLM, and Iberia can get you from Ontario to London in just under 16h 45m. Your travel time can differ by up to 3h 15m. Airlines will cover a distance of 5407 mi. This flight may include one or multiple stops.

What are the cheapest airlines flying from Ontario to London round-trip?

Flying on Virgin Atlantic is currently your cheapest option to London, with prices starting at $469. Additional round-trip tickets that might be worth considering are offered by Delta and KLM, with the lowest prices starting at $572 and $580, respectively. You may be able to fly from Ontario to London for 40% less than the average price by searching for these airlines.

What are the cheapest airlines to fly from Ontario to London one-way?

The cheapest airlines for a one-way flight from Ontario to London are KLM ($403), United Airlines ($403), and Delta ($403).

In terms of precipitation, rainfall in London ranges from 1.6 - 2.8 inches per month. January is typically the wettest month, when rainfall can reach 2.8 in. July is typically the driest time to visit London when rainfall is around 1.6 in.

If weather is an important factor for your trip to London, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 62.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 39.2 F).

What are the most popular routes from Ontario to London?

The most popular flight routes from Ontario to London are Ontario - London Heathrow, Ontario - London Gatwick and Ontario - London City.

What are the most popular airlines that fly from Ontario to London?

Before booking your flight from Ontario to London check out the most popular airlines for this route: United Airlines, British Airways or American Airlines.

Most accurate provider : When it comes to deals on Ontario-London flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Ontario-London flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Ontario-London flight searches over the past month and is updated monthly.

Most trusted provider : When it comes to deals on Ontario-London flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Ontario-London flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

What airport do you fly from for flights from Ontario to London?

Most people fly from Ontario (ONT) if they book a flight from Ontario to London. On average, Ontario has 0 outbound flights to London per day from 7 airlines. Ontario is conveniently located just 3.1 mi from Ontario’s city center.

Can I find deals for flights from Ontario to London that include hotel bookings?

Yes. In addition to deals on Ontario to London flights, Cheapflights offers vacation packages that include both flights and hotel.

How can I find direct flights from Ontario to London?

After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Ontario to London.

Can I find deals for business class flights from Ontario to London?

Yes. Cheapflights offers flight deals from Ontario to London by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

$388+ Cheap Flights from Ontario to London

Q: How much does it cost to fly round-trip from Ontario to London?

Airfare is below average for this route at the moment. Ontario to London flights typically cost between $623 and $695 in December. The cheapest round-trip price found within the last 3 days was $589 on Virgin Atlantic (Dec 2-Dec 16).

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Find cheap flights from Ontario to London with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

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Cheap flight deals from Ontario to London

Most accurate provider	FlightHub 3 stars
Most trusted provider	FlightHub 3 stars
Round-trip from	$589 (Netflights)
One-way from	$388 (Justfly.com)
Popular in	June
Cheapest in	October
Average price	$678

Provider with most accurate pricing for Ontario-London (LON) flight deals.

Search Deals

Provider most trusted by Cheapflights users for Ontario-London (LON) flights.

Search Deals

From Ontario to London (LON)

Search Deals

One-way flight from Ontario to London (LON)

Search Deals

Highest demand for flights based on searches. 12% potential increase in price ($113 potential increase over avg. RT price).

Search Deals

Cheapest flight prices on average. 3% potential price decrease ($26 potential savings vs. average RT price).

Search Deals

Average for round-trip flights in October 2025

Search Deals

Find flight deals from Ontario to London

Cheapest flights from Ontario to London
Explore the most affordable flight options available from Ontario to London. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 14, 2025.

Tue 12/26:00 amONT - LHR

1 stop20h 00mVirgin Atlantic

Tue 12/1610:45 amLHR - ONT

1 stop21h 13mVirgin Atlantic

Deal found 10/14

$589

Sun 10/194:49 pmONT - LHR

1 stop12h 01mBritish Airways

Tue 11/43:00 pmLHR - ONT

1 stop15h 29mBritish Airways

Deal found 10/13

$615

Mon 10/134:49 pmONT - LHR

1 stop12h 01mBritish Airways

Tue 10/283:00 pmLHR - ONT

1 stop14h 42mBritish Airways

Deal found 10/13

$620

Mon 10/134:49 pmONT - LHR

1 stop12h 01mAmerican Airlines

Tue 10/283:00 pmLHR - ONT

1 stop14h 42mAmerican Airlines

Deal found 10/12

$621

Wed 10/2210:57 amONT - LHR

1 stop14h 03mBritish Airways

Wed 11/510:05 amLHR - ONT

1 stop16h 16mBritish Airways

Deal found 10/12

$622

Wed 10/227:05 amONT - LHR

1 stop22h 25mVirgin Atlantic

Tue 11/46:30 amLHR - ONT

2 stops24h 11mVirgin Atlantic

Deal found 10/13

$623

Tue 11/116:00 amONT - LHR

2 stops18h 45mDelta

Thu 11/208:55 amLHR - ONT

2 stops22h 09mDelta

Deal found 10/13

$625

Tue 10/214:49 pmONT - LHR

1 stop12h 01mBritish Airways

Tue 10/283:00 pmLHR - ONT

1 stop14h 42mBritish Airways

Deal found 10/13

$628

Mon 12/2910:29 pmONT - LHR

1 stop23h 56mDelta

Wed 1/2110:45 amLHR - ONT

1 stop18h 29mDelta

Deal found 10/13

$629

Tue 11/185:49 pmONT - LHR

2 stops18h 21mDelta

Wed 11/264:35 pmLHR - ONT

2 stops35h 07mDelta

Deal found 10/11

$633

Tue 11/117:00 amONT - LCY

2 stops21h 50mMultiple Airlines

Thu 11/209:40 amLCY - ONT

2 stops21h 11mMultiple Airlines

Deal found 10/13

$693

Wed 11/266:00 amONT - LCY

2 stops26h 40mMultiple Airlines

Wed 12/39:50 amLCY - ONT

2 stops20h 59mMultiple Airlines

Deal found 10/12

$704

Best flights from Ontario to London
Discover carefully curated flight deals from Ontario to London that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated October 14, 2025.

Wed 11/266:00 amONT - LHR

1 stop20h 00mDelta

Wed 12/39:00 amLHR - ONT

2 stops22h 04mDelta

Deal found 10/12

$621

Tue 11/117:05 amONT - LHR

1 stop16h 45mKLM

Tue 11/1812:20 pmLHR - ONT

1 stop18h 35mKLM

Deal found 10/12

$629

Tue 2/1711:05 amONT - LCY

2 stops19h 00mIberia

Fri 2/277:50 amLCY - ONT

2 stops22h 07mIberia

Deal found 10/14

$646

Tue 11/117:00 amONT - LCY

2 stops21h 50mMultiple Airlines

Thu 11/209:40 amLCY - ONT

2 stops21h 11mMultiple Airlines

Deal found 10/13

$693

Wed 3/46:47 amONT - LGW

2 stops18h 13mAmerican Airlines

Sun 3/812:30 pmLGW - ONT

2 stops36h 19mAmerican Airlines

Deal found 10/13

$849

Tue 11/117:05 amONT - LHR

2 stops17h 40mDelta

Tue 11/1811:30 amLHR - ONT

2 stops19h 34mDelta

Deal found 10/12

$625

Wed 12/316:38 amONT - LHR

1 stop19h 52mDelta

Tue 2/32:45 pmLHR - ONT

1 stop15h 53mDelta

Deal found 10/13

$629

Tue 11/117:00 amONT - LCY

2 stops21h 50mMultiple Airlines

Tue 11/189:50 amLCY - ONT

2 stops19h 59mMultiple Airlines

Deal found 10/12

$693

Mon 12/2910:29 pmONT - LHR

1 stop23h 56mDelta

Fri 1/2310:45 amLHR - ONT

1 stop18h 29mDelta

Deal found 10/13

$629

Wed 11/266:00 amONT - LCY

2 stops26h 40mMultiple Airlines

Wed 12/39:50 amLCY - ONT

2 stops20h 59mMultiple Airlines

Deal found 10/12

$704

Tue 12/27:00 amONT - LCY

2 stops17h 50mIberia

Wed 12/107:50 amLCY - ONT

2 stops22h 38mIberia

Deal found 10/13

$821

Wed 11/191:20 pmONT - LHR

1 stop12h 40mDelta

Wed 11/2610:45 amLHR - ONT

1 stop16h 57mDelta

Deal found 10/12

$629

Tue 12/21:50 pmONT - LCY

2 stops19h 45mMultiple Airlines

Tue 12/169:50 amLCY - ONT

2 stops39h 45mMultiple Airlines

Deal found 10/13

$709

Tue 11/1811:48 amONT - LHR

1 stop14h 42mDelta

Wed 11/268:00 pmLHR - ONT

2 stops31h 42mDelta

Deal found 10/12

$633

Tue 12/26:10 amONT - LGW

2 stops20h 40mIberia

Wed 12/107:40 pmLGW - ONT

2 stops24h 13mIberia

Deal found 10/13

$843

Tue 11/187:00 amONT - LCY

2 stops21h 50mMultiple Airlines

Mon 11/245:15 pmLCY - ONT

2 stops35h 29mMultiple Airlines

Deal found 10/14

$713

Tue 11/185:49 pmONT - LHR

2 stops18h 21mDelta

Tue 11/2510:45 amLHR - ONT

1 stop20h 19mDelta

Deal found 10/12

$633

Mon 1/1210:58 amONT - LGW

2 stops48h 02mIberia

Wed 1/2811:45 amLGW - ONT

2 stops34h 33mIberia

Deal found 10/13

$852

Thu 11/277:00 amONT - LCY

2 stops21h 50mMultiple Airlines

Wed 12/39:50 amLCY - ONT

2 stops20h 59mMultiple Airlines

Deal found 10/13

$729

Sun 1/116:45 amONT - LHR

1 stop19h 45mDelta

Wed 1/2812:20 pmLHR - ONT

1 stop18h 18mDelta

Deal found 10/13

$637

Tue 12/21:50 pmONT - LCY

2 stops19h 45mMultiple Airlines

Mon 12/159:50 amLCY - ONT

2 stops20h 59mMultiple Airlines

Deal found 10/13

$754

Sun 1/410:29 pmONT - LHR

1 stop23h 56mDelta

Thu 1/2910:45 amLHR - ONT

1 stop18h 29mDelta

Deal found 10/13

$637

Tue 1/610:30 pmONT - LHR

1 stop23h 55mDelta

Thu 1/2910:45 amLHR - ONT

1 stop18h 29mDelta

Deal found 10/13

$637

Fri 1/96:00 amONT - LCY

3 stops21h 40mMultiple Airlines

Sat 1/3112:20 pmLCY - ONT

3 stops42h 33mMultiple Airlines

Deal found 10/13

$795

Wed 12/315:05 amONT - LCY

3 stops20h 00mMultiple Airlines

Thu 1/229:40 amLCY - ONT

2 stops20h 18mMultiple Airlines

Deal found 10/13

$805

Mon 11/1011:48 amONT - LHR

1 stop17h 02mDelta

Sun 11/236:20 amLHR - ONT

2 stops24h 35mDelta

Deal found 10/14

$671

Wed 11/267:05 amONT - LCY

2 stops17h 45mDelta

Wed 12/37:45 amLCY - ONT

2 stops23h 19mDelta

Deal found 10/12

$791

Tue 11/1111:15 amONT - LGW

2 stops15h 40mMultiple Airlines

Tue 11/1811:55 amLGW - ONT

2 stops18h 10mMultiple Airlines

Deal found 10/12

$960

Wed 3/46:00 amONT - LGW

2 stops20h 55mMultiple Airlines

Sun 3/811:55 amLGW - ONT

2 stops17h 42mMultiple Airlines

Deal found 10/13

$978

Wed 11/196:00 amONT - LGW

2 stops20h 55mMultiple Airlines

Sun 11/2311:55 amLGW - ONT

2 stops20h 04mMultiple Airlines

Deal found 10/14

$978

Last-minute flights from Ontario to London
Discover last-minute flight deals from Ontario to London. Data last updated October 14, 2025 and is based on user searches.

Mon 10/134:49 pmONT - LHR

1 stop12h 01mBritish Airways

Tue 10/283:00 pmLHR - ONT

1 stop14h 42mBritish Airways

Deal found 10/13

$620

Mon 10/134:49 pmONT - LHR

1 stop12h 01mAmerican Airlines

Tue 10/283:00 pmLHR - ONT

1 stop14h 42mAmerican Airlines

Deal found 10/12

$621

Mon 10/137:05 amONT - LHR

1 stop16h 10mVirgin Atlantic

Tue 10/282:45 pmLHR - ONT

1 stop14h 56mVirgin Atlantic

Deal found 10/12

$636

Sun 10/194:49 pmONT - LHR

1 stop12h 01mBritish Airways

Tue 11/43:00 pmLHR - ONT

1 stop15h 29mBritish Airways

Deal found 10/13

$615

Tue 10/214:49 pmONT - LHR

1 stop12h 01mBritish Airways

Tue 10/283:00 pmLHR - ONT

1 stop14h 42mBritish Airways

Deal found 10/13

$628

Wed 10/2210:57 amONT - LHR

1 stop14h 03mBritish Airways

Wed 11/510:05 amLHR - ONT

1 stop16h 16mBritish Airways

Deal found 10/12

$622

Wed 10/227:05 amONT - LHR

1 stop22h 25mVirgin Atlantic

Tue 11/46:30 amLHR - ONT

2 stops24h 11mVirgin Atlantic

Deal found 10/13

$623

Mon 11/106:45 amONT - LHR

1 stop19h 45mVirgin Atlantic

Sun 11/2310:45 amLHR - ONT

1 stop21h 07mVirgin Atlantic

Deal found 10/14

$640

Tue 11/116:00 amONT - LHR

2 stops18h 45mDelta

Thu 11/208:55 amLHR - ONT

2 stops22h 09mDelta

Deal found 10/13

$625

Tue 11/117:00 amONT - LCY

2 stops21h 50mMultiple Airlines

Thu 11/209:40 amLCY - ONT

2 stops21h 11mMultiple Airlines

Deal found 10/13

$693

Tue 11/181:20 pmONT - LHR

1 stop12h 40mDelta

Thu 11/2710:45 amLHR - ONT

1 stop15h 19mDelta

Deal found 10/12

$629

Tue 11/185:49 pmONT - LHR

2 stops18h 21mDelta

Wed 11/264:35 pmLHR - ONT

2 stops35h 07mDelta

Deal found 10/11

$633

One-way flights from Ontario to London
Search for one-way flight options from Ontario to London. Find affordable one-way fares based on user searches. Data last updated October 14, 2025.

Mon 3/25:40 amONT - LHR

2 stops17h 30mAir Canada

Deal found 10/14

$388

Wed 12/315:05 amONT - LHR

2 stops18h 05mAir Canada

Deal found 10/13

$392

Mon 12/295:05 amONT - LHR

2 stops41h 25mAir Canada

Deal found 10/13

$395

Tue 11/1112:46 pmONT - LHR

1 stop13h 14mBritish Airways

Deal found 10/14

$397

Tue 12/305:05 amONT - LHR

2 stops41h 25mAir Canada

Deal found 10/14

$398

Wed 4/13:09 pmONT - LHR

1 stop13h 21mBritish Airways

Deal found 10/14

$399

Wed 11/191:20 pmONT - LHR

1 stop12h 40mVirgin Atlantic

Deal found 10/13

$400

Mon 3/301:00 pmONT - LHR

1 stop12h 50mKLM

Deal found 10/14

$403

Sat 11/811:36 amONT - LHR

1 stop34h 49mVirgin Atlantic

Deal found 10/12

$404

Sun 3/295:00 amONT - LHR

2 stops17h 35mAir Canada

Deal found 10/14

$409

Sun 11/26:38 pmONT - LHR

1 stop28h 47mUnited Airlines

Deal found 10/13

$415

Mon 11/31:29 pmONT - LHR

2 stops33h 41mAir Canada

Deal found 10/14

$416

Fly from

Fly to

Route

Depart

Return

Price

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 11/26

6:00 am-10:00 am

1 stop20h 00m

London Heathrow

Wed 12/3

9:00 am-11:04 pm

2 stops22h 04m

$621

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 11/11

7:05 am-8:45 am

2 stops17h 40m

London Heathrow

Tue 11/18

11:30 am-11:04 pm

2 stops19h 34m

$625

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 11/11

7:05 am-7:50 am

1 stop16h 45m

London Heathrow

Tue 11/18

12:20 pm-10:55 pm

1 stop18h 35m

$629

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 12/31

6:38 am-10:30 am

1 stop19h 52m

London Heathrow

Tue 2/3

2:45 pm-10:38 pm

1 stop15h 53m

$629

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 12/29

10:29 pm-6:25 am

1 stop23h 56m

London Heathrow

Fri 1/23

10:45 am-9:14 pm

1 stop18h 29m

$629

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 11/19

1:20 pm-10:00 am

1 stop12h 40m

London Heathrow

Wed 11/26

10:45 am-7:42 pm

1 stop16h 57m

$629

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 11/18

11:48 am-10:30 am

1 stop14h 42m

London Heathrow

Wed 11/26

8:00 pm-7:42 pm

2 stops31h 42m

$633

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 11/18

5:49 pm-8:10 pm

2 stops18h 21m

London Heathrow

Tue 11/25

10:45 am-11:04 pm

1 stop20h 19m

$633

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 1/11

6:45 am-10:30 am

1 stop19h 45m

London Heathrow

Wed 1/28

12:20 pm-10:38 pm

1 stop18h 18m

$637

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 1/4

10:29 pm-6:25 am

1 stop23h 56m

London Heathrow

Thu 1/29

10:45 am-9:14 pm

1 stop18h 29m

$637

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/14

Showing 1-10 of 60 results

...

Compare providers for flights from Ontario to London

Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Ontario to London in October.

Provider	Price Accuracy	Trust Score*
Expedia	Price Accuracy2 stars	Trust Score*3 stars
FlightHub	Price Accuracy3 stars	Trust Score*3 stars
eDreams	Price Accuracy3 stars	Trust Score*3 stars
AranGrant	Price Accuracy3 stars	Trust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

Most accurate provider: When it comes to deals on Ontario-London flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Ontario-London flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Ontario-London flight searches over the past month and is updated monthly.
Most trusted provider: When it comes to deals on Ontario-London flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Ontario-London flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Ontario to London

Have a flexible travel schedule? Discover the best time to fly to London from Ontario with our price prediction graph.

Estimated round-trip price

Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Ontario to London

What is the cheapest month to book a flight from Ontario to London?

Currently, October is the cheapest month in which you can book a flight from Ontario to London (average of $245). Flying from Ontario to London in June is currently the most expensive (average of $564). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from ONT to LON?

It’s optimal to fly from Ontario to London in the afternoon. By choosing this option you can save up to 37% on the cost of your flight, compared to a flight at noon.

What is the cheapest day to fly from Ontario to London?

Travelers seeking maximum savings on their Ontario to London flight should consider departing on Tuesday mornings when fares are most often at their lowest. Sunday evenings flights should be avoided if possible as fares are typically the most expensive at this time.

How much does it cost to fly round-trip from Ontario to London?

Reviews of airlines servicing London

Get a feel of what it's like to fly with Delta, United Airlines, and American Airlines from Ontario to London by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.

Delta

8.0

Very good

7,977 reviews

Reviews

1 / 20

10.0

Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

Delta

8.0

Very good

7,977 reviews

Delta

8.0

Very good

7,977 reviews

Reviews

1 / 20

10.0

Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

United Airlines

7.4

Good

8,977 reviews

Delta

8.0

Very good

7,977 reviews

Reviews

1 / 20

10.0

Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

American Airlines

7.2

Good

11,044 reviews

Delta

8.0

Very good

7,977 reviews

Reviews

1 / 20

10.0

Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

Iberia

7.0

Good

2,990 reviews

Delta

8.0

Very good

7,977 reviews

Reviews

1 / 20

10.0

Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

British Airways

6.7

Okay

7,457 reviews

Delta

8.0

Very good

7,977 reviews

Reviews

1 / 20

10.0

Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

Related info for your journey

What airport do you fly from for flights from Ontario to London?
Most people fly from Ontario (ONT) if they book a flight from Ontario to London. On average, Ontario has 0 outbound flights to London per day from 7 airlines. Ontario is conveniently located just 3.1 mi from Ontario’s city center.
How long is the flight from Ontario to London?
Delta, KLM, and Iberia can get you from Ontario to London in just under 16h 45m. Your travel time can differ by up to 3h 15m. Airlines will cover a distance of 5407 mi. This flight may include one or multiple stops.
What are the cheapest airlines flying from Ontario to London round-trip?
Flying on Virgin Atlantic is currently your cheapest option to London, with prices starting at $469. Additional round-trip tickets that might be worth considering are offered by Delta and KLM, with the lowest prices starting at $572 and $580, respectively. You may be able to fly from Ontario to London for 40% less than the average price by searching for these airlines.
What are the cheapest airlines to fly from Ontario to London one-way?
The cheapest airlines for a one-way flight from Ontario to London are KLM ($403), United Airlines ($403), and Delta ($403).
What are the most popular routes from Ontario to London?
The most popular flight routes from Ontario to London are Ontario - London Heathrow, Ontario - London Gatwick and Ontario - London City.
Can I find deals for flights from Ontario to London that include hotel bookings?
Yes. In addition to deals on Ontario to London flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from Ontario to London?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Ontario to London.
Can I find deals for business class flights from Ontario to London?
Yes. Cheapflights offers flight deals from Ontario to London by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.
What is the cheapest month to book a flight from Ontario to London?
Currently, October is the cheapest month in which you can book a flight from Ontario to London (average of $245). Flying from Ontario to London in June is currently the most expensive (average of $564). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Hounslow

Hayes

Ilford

Southend-on-Sea

Harrow

Canterbury

Croydon

Eastleigh

Dartford

Dover

Winchester

Orpington

Gatwick

Borehamwood

Aylesbury

Bedford

Chipping Norton

Wembley

Folkestone

Eastbourne

Browse thousands of different options on Cheapflights for your next trip

Top 7 airlines flying from Ontario to London

Airline	Cheapest	Average	Flexibility	On-time
Virgin Atlantic	Cheapest$469	Average$884	FlexibilityNo cancel fee	On-time72%
Delta	Cheapest$572	Average$676	FlexibilityNo cancel fee	On-timeN/A
KLM	Cheapest$580	Average$672	FlexibilityNo cancel fee	On-time75%
Iberia	Cheapest$615	Average$689	FlexibilityNo cancel fee	On-time77%
American Airlines	Cheapest$653	Average$959	FlexibilityNo cancel fee	On-time71%
British Airways	Cheapest$662	Average$867	FlexibilityNo cancel fee	On-time70%
United Airlines	Cheapest$677	Average$840	FlexibilityNo cancel fee	On-time69%

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$388+ Cheap flights from Ontario (ONT) to London (LON)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 3/2. Fares are subject to change and may not be available on all flights or dates of travel.

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Find flight deals from Ontario to London

Cheapest flights from Ontario to LondonExplore the most affordable flight options available from Ontario to London. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 14, 2025.

Explore the most affordable flight options available from Ontario to London. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 14, 2025.

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

Compare providers for flights from Ontario to London

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.

Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Ontario to London in October.

Best time to book a flight from Ontario to London

Have a flexible travel schedule? Discover the best time to fly to London from Ontario with our price prediction graph.

Cheapflights Insights

Everything you need to know about your flight from Ontario to London

What is the cheapest month to book a flight from Ontario to London?

What is the cheapest time of day to fly from ONT to LON?

Find hourly flight availability from Ontario to London. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated October 14, 2025.

What is the cheapest day to fly from Ontario to London?

Use this chart to determine the cheapest time to fly round-trip from Ontario to London. Price data was last updated on December 16, 2024.

How much does it cost to fly round-trip from Ontario to London?

Reviews of airlines servicing London

Get a feel of what it's like to fly with Delta, United Airlines, and American Airlines from Ontario to London by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.

Related info for your journey

Find useful and relevant information for your journey from Ontario to London. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

What airport do you fly from for flights from Ontario to London?

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What are the cheapest airlines flying from Ontario to London round-trip?

What are the cheapest airlines to fly from Ontario to London one-way?

What are the most popular routes from Ontario to London?

Can I find deals for flights from Ontario to London that include hotel bookings?

How can I find direct flights from Ontario to London?

Can I find deals for business class flights from Ontario to London?

What is the cheapest month to book a flight from Ontario to London?

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Alternative routes for Ontario to London

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Top 7 airlines flying from Ontario to London

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Cheapest flights from Ontario to London
Explore the most affordable flight options available from Ontario to London. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 14, 2025.