How long is the flight from Ontario to London?

United Airlines, Delta, and Virgin Atlantic can get you from Ontario to London in just under 14h 07m. Your travel time can differ by up to 9h 48m. 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 Delta is currently your cheapest option to London, with prices starting at $572. Additional round-trip tickets that might be worth considering are offered by KLM and Iberia, with the lowest prices starting at $580 and $615, respectively. You may be able to fly from Ontario to London for 26% 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 United Airlines ($399), Iberia ($546), and Delta ($592).

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 eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on Ontario-London flight deals on Cheapflights vs. eDreams >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 eDreams the most. eDreams 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 6 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.

$339+ 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 $674 and $895 in January. The cheapest round-trip price found within the last 3 days was $624 on United Airlines (Jan 20-Jan 27).

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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

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheap flight deals from Ontario to London

Most accurate provider	eDreams 3 stars
Most trusted provider	eDreams 3 stars
Round-trip from	$624 (United Airlines)
One-way from	$339 (Kiwi.com)
Popular in	June
Cheapest in	October
Average price	$728

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. 14% potential increase in price ($130 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 November 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 November 25, 2025.

Mon 12/295:05 amONT - LHR

2 stops41h 25mMultiple Airlines

Fri 1/912:05 pmLHR - ONT

1 stop17h 53mMultiple Airlines

Deal found 11/24

$638

Mon 12/295:05 amONT - LHR

2 stops41h 25mAir Canada

Fri 1/91:25 pmLHR - ONT

2 stops31h 22mAir Canada

Deal found 11/24

$642

Mon 12/296:39 pmONT - LHR

1 stop28h 46mUnited Airlines

Fri 1/912:05 pmLHR - ONT

1 stop17h 53mUnited Airlines

Deal found 11/24

$644

Tue 12/91:34 pmONT - LHR

1 stop12h 06mUnited Airlines

Tue 12/1610:05 amLHR - ONT

1 stop15h 32mUnited Airlines

Deal found 11/24

$674

Tue 12/912:40 pmONT - LHR

1 stop13h 50mDelta

Thu 12/2510:45 amLHR - ONT

1 stop17h 05mDelta

Deal found 11/25

$675

Wed 12/105:05 amONT - LHR

2 stops17h 25mMultiple Airlines

Fri 1/912:05 pmLHR - ONT

1 stop17h 53mMultiple Airlines

Deal found 11/24

$679

Wed 12/105:05 amONT - LHR

2 stops17h 25mAir Canada

Fri 1/91:25 pmLHR - ONT

2 stops31h 22mAir Canada

Deal found 11/24

$685

Sun 12/71:50 pmONT - LHR

1 stop14h 10mUnited Airlines

Sun 12/1410:05 amLHR - ONT

1 stop15h 32mUnited Airlines

Deal found 11/23

$724

Thu 12/111:34 pmONT - LHR

1 stop12h 06mUnited Airlines

Thu 12/181:35 pmLHR - ONT

1 stop16h 50mUnited Airlines

Deal found 11/25

$725

Sat 12/275:05 amONT - LHR

1 stop20h 35mUnited Airlines

Sun 1/1111:35 amLHR - ONT

1 stop17h 23mUnited Airlines

Deal found 11/23

$765

Thu 12/111:34 pmONT - LHR

1 stop12h 06mUnited Airlines

Mon 12/2210:05 amLHR - ONT

1 stop15h 38mUnited Airlines

Deal found 11/24

$774

Wed 12/106:00 amONT - LHR

1 stop20h 00mKLM

Fri 1/912:20 pmLHR - ONT

1 stop18h 31mKLM

Deal found 11/24

$779

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 November 25, 2025.

Tue 1/201:53 pmONT - LHR

1 stop14h 07mUnited Airlines

Tue 1/276:35 amLHR - ONT

2 stops19h 08mUnited Airlines

Deal found 11/24

$624

Wed 1/2810:30 pmONT - LHR

1 stop23h 55mDelta

Sun 2/18:40 amLHR - ONT

2 stops20h 25mDelta

Deal found 11/24

$625

Mon 1/126:00 amONT - LHR

1 stop20h 00mVirgin Atlantic

Sat 1/316:30 amLHR - ONT

2 stops24h 21mVirgin Atlantic

Deal found 11/25

$626

Fri 2/137:10 amONT - LHR

1 stop15h 40mMultiple Airlines

Sat 2/218:20 amLHR - ONT

1 stop16h 04mMultiple Airlines

Deal found 11/24

$652

Sat 1/174:45 pmONT - LGW

2 stops32h 15mAmerican Airlines

Mon 2/211:20 amLGW - ONT

2 stops34h 58mAmerican Airlines

Deal found 11/24

$804

Thu 3/57:10 amONT - LCY

2 stops17h 40mIberia

Thu 3/127:50 amLCY - ONT

2 stops23h 09mIberia

Deal found 11/25

$877

Mon 1/56:39 pmONT - LHR

2 stops55h 01mUnited Airlines

Tue 1/206:30 amLHR - ONT

2 stops23h 29mUnited Airlines

Deal found 11/23

$627

Fri 1/96:00 amONT - LHR

2 stops18h 45mDelta

Sun 1/186:30 amLHR - ONT

2 stops24h 21mDelta

Deal found 11/23

$630

Wed 1/2812:41 pmONT - LHR

1 stop14h 59mVirgin Atlantic

Sun 2/110:45 amLHR - ONT

1 stop13h 30mVirgin Atlantic

Deal found 11/24

$652

Tue 1/207:30 amONT - LHR

2 stops19h 00mDelta

Tue 1/278:40 amLHR - ONT

2 stops20h 25mDelta

Deal found 11/22

$630

Thu 1/221:24 pmONT - LHR

1 stop12h 16mUnited Airlines

Wed 2/410:30 amLHR - ONT

2 stops18h 28mUnited Airlines

Deal found 11/24

$634

Thu 1/297:30 amONT - LCY

2 stops28h 05mVirgin Atlantic

Mon 2/25:05 pmLCY - ONT

2 stops37h 46mVirgin Atlantic

Deal found 11/23

$659

Mon 1/261:24 pmONT - LHR

1 stop12h 16mUnited Airlines

Wed 2/410:30 amLHR - ONT

2 stops18h 28mUnited Airlines

Deal found 11/24

$634

Fri 1/231:24 pmONT - LHR

1 stop12h 16mUnited Airlines

Sat 2/1410:05 amLHR - ONT

1 stop15h 36mUnited Airlines

Deal found 11/22

$652

Fri 1/91:24 pmONT - LHR

1 stop12h 16mUnited Airlines

Sun 1/1810:05 amLHR - ONT

1 stop15h 38mUnited Airlines

Deal found 11/22

$652

Wed 4/156:00 amONT - LGW

2 stops24h 40mMultiple Airlines

Tue 5/51:00 pmLGW - ONT

2 stops16h 50mMultiple Airlines

Deal found 11/24

$967

Wed 3/46:14 amONT - LGW

2 stops20h 41mMultiple Airlines

Sun 3/811:55 amLGW - ONT

2 stops18h 37mMultiple Airlines

Deal found 11/24

$974

Tue 3/179:20 amONT - LGW

2 stops18h 35mMultiple Airlines

Tue 3/2411:55 amLGW - ONT

2 stops17h 43mMultiple Airlines

Deal found 11/24

$974

Thu 1/226:00 amONT - LGW

2 stops20h 55mMultiple Airlines

Fri 1/3011:55 amLGW - ONT

2 stops20h 01mMultiple Airlines

Deal found 11/24

$974

Tue 4/2111:30 amONT - LGW

2 stops19h 10mMultiple Airlines

Tue 5/121:00 pmLGW - ONT

2 stops16h 50mMultiple Airlines

Deal found 11/24

$997

Mon 1/510:44 amONT - LGW

2 stops16h 11mMultiple Airlines

Tue 1/2011:55 amLGW - ONT

2 stops17h 50mMultiple Airlines

Deal found 11/23

$1,012

Mon 12/2910:50 amONT - LCY

2 stops19h 45mIberia

Fri 1/97:15 pmLCY - ONT

2 stops27h 03mIberia

Deal found 11/24

$1,762

Thu 3/56:14 amONT - LGW

2 stops20h 41mMultiple Airlines

Thu 3/1211:55 amLGW - ONT

2 stops17h 50mMultiple Airlines

Deal found 11/24

$1,024

Fri 1/98:55 amONT - LGW

2 stops18h 00mMultiple Airlines

Fri 1/1611:55 amLGW - ONT

2 stops20h 01mMultiple Airlines

Deal found 11/25

$1,101

Thu 1/86:00 amONT - LCY

2 stops18h 50mMultiple Airlines

Thu 1/157:50 amLCY - ONT

2 stops22h 58mMultiple Airlines

Deal found 11/24

$1,155

Sat 12/1312:53 pmONT - LCY

2 stops41h 42mIberia

Sun 12/287:15 pmLCY - ONT

2 stops48h 38mIberia

Deal found 11/24

$2,293

Thu 12/117:03 amONT - LCY

2 stops17h 47mIberia

Sun 12/287:15 pmLCY - ONT

2 stops34h 59mIberia

Deal found 11/25

$2,399

Fri 3/2710:30 pmONT - LCY

2 stops34h 50mMultiple Airlines

Sun 4/57:10 pmLCY - ONT

2 stops35h 01mMultiple Airlines

Deal found 11/23

$1,281

Tue 12/2310:50 amONT - LCY

2 stops19h 15mIberia

Wed 12/317:15 pmLCY - ONT

2 stops24h 38mIberia

Deal found 11/25

$3,977

Last-minute flights from Ontario to London
Discover last-minute flight deals from Ontario to London. Data last updated November 25, 2025 and is based on user searches.

Sun 12/71:50 pmONT - LHR

1 stop14h 10mUnited Airlines

Sun 12/1410:05 amLHR - ONT

1 stop15h 32mUnited Airlines

Deal found 11/23

$724

Tue 12/91:34 pmONT - LHR

1 stop12h 06mUnited Airlines

Tue 12/1610:05 amLHR - ONT

1 stop15h 32mUnited Airlines

Deal found 11/24

$674

Tue 12/912:40 pmONT - LHR

1 stop13h 50mDelta

Thu 12/2510:45 amLHR - ONT

1 stop17h 05mDelta

Deal found 11/25

$675

Wed 12/105:05 amONT - LHR

2 stops17h 25mMultiple Airlines

Fri 1/912:05 pmLHR - ONT

1 stop17h 53mMultiple Airlines

Deal found 11/24

$679

Wed 12/105:05 amONT - LHR

2 stops17h 25mAir Canada

Fri 1/91:25 pmLHR - ONT

2 stops31h 22mAir Canada

Deal found 11/24

$685

Wed 12/106:00 amONT - LHR

1 stop20h 00mKLM

Fri 1/912:20 pmLHR - ONT

1 stop18h 31mKLM

Deal found 11/24

$779

Thu 12/111:34 pmONT - LHR

1 stop12h 06mUnited Airlines

Thu 12/181:35 pmLHR - ONT

1 stop16h 50mUnited Airlines

Deal found 11/25

$725

Thu 12/111:34 pmONT - LHR

1 stop12h 06mUnited Airlines

Mon 12/2210:05 amLHR - ONT

1 stop15h 38mUnited Airlines

Deal found 11/24

$774

Sat 12/275:05 amONT - LHR

1 stop20h 35mUnited Airlines

Sun 1/1111:35 amLHR - ONT

1 stop17h 23mUnited Airlines

Deal found 11/23

$765

Mon 12/295:05 amONT - LHR

2 stops41h 25mMultiple Airlines

Fri 1/912:05 pmLHR - ONT

1 stop17h 53mMultiple Airlines

Deal found 11/24

$638

Mon 12/295:05 amONT - LHR

2 stops41h 25mAir Canada

Fri 1/91:25 pmLHR - ONT

2 stops31h 22mAir Canada

Deal found 11/24

$642

Mon 12/296:39 pmONT - LHR

1 stop28h 46mUnited Airlines

Fri 1/912:05 pmLHR - ONT

1 stop17h 53mUnited Airlines

Deal found 11/24

$644

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 November 25, 2025.

Tue 12/96:15 amONT - LHR

3 stops49h 15mMultiple Airlines

Deal found 11/24

$339

Tue 1/204:45 pmONT - LHR

1 stop12h 30mBritish Airways

Deal found 11/22

$380

Tue 12/912:46 pmONT - LHR

1 stop13h 14mBritish Airways

Deal found 11/23

$389

Mon 2/235:06 pmONT - LHR

1 stop12h 09mBritish Airways

Deal found 11/24

$391

Mon 1/264:45 pmONT - LHR

1 stop12h 30mBritish Airways

Deal found 11/25

$394

Sun 4/125:10 amONT - LHR

2 stops19h 25mAir Canada

Deal found 11/24

$395

Sat 1/105:05 amONT - LHR

1 stop20h 35mAir Canada

Deal found 11/24

$397

Thu 1/226:00 amONT - LHR

1 stop17h 25mUnited Airlines

Deal found 11/23

$399

Wed 12/106:00 amONT - LHR

1 stop20h 15mUnited Airlines

Deal found 11/24

$400

Mon 12/85:05 amONT - LHR

2 stops19h 20mUnited Airlines

Deal found 11/24

$403

Mon 3/236:00 amONT - LHR

3 stops28h 30mMultiple Airlines

Deal found 11/23

$406

Wed 5/204:45 pmONT - LGW

2 stops33h 15mMultiple Airlines

Deal found 11/25

$510

Fly from

Fly to

Route

Depart

Return

Price

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 1/20

1:53 pm-12:00 pm

1 stop14h 07m

London Heathrow

Tue 1/27

6:35 am-5:43 pm

2 stops19h 08m

$624

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 1/28

10:30 pm-6:25 am

1 stop23h 55m

London Heathrow

Sun 2/1

8:40 am-9:05 pm

2 stops20h 25m

$625

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 1/12

6:00 am-10:00 am

1 stop20h 00m

London Heathrow

Sat 1/31

6:30 am-10:51 pm

2 stops24h 21m

$626

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 1/5

6:39 pm-9:40 am

2 stops55h 01m

London Heathrow

Tue 1/20

6:30 am-9:59 pm

2 stops23h 29m

$627

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 1/9

6:00 am-8:45 am

2 stops18h 45m

London Heathrow

Sun 1/18

6:30 am-10:51 pm

2 stops24h 21m

$630

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Tue 1/20

7:30 am-10:30 am

2 stops19h 00m

London Heathrow

Tue 1/27

8:40 am-9:05 pm

2 stops20h 25m

$630

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Thu 1/22

1:24 pm-9:40 am

1 stop12h 16m

London Heathrow

Wed 2/4

10:30 am-8:58 pm

2 stops18h 28m

$634

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 1/26

1:24 pm-9:40 am

1 stop12h 16m

London Heathrow

Wed 2/4

10:30 am-8:58 pm

2 stops18h 28m

$634

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 2/13

7:10 am-6:50 am

1 stop15h 40m

London Heathrow

Sat 2/21

8:20 am-4:24 pm

1 stop16h 04m

$652

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 1/28

12:41 pm-11:40 am

1 stop14h 59m

London Heathrow

Sun 2/1

10:45 am-4:15 pm

1 stop13h 30m

$652

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/24

Showing 1-10 of 59 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 November.

Provider	Price Accuracy	Trust Score*
Expedia	Price Accuracy2 stars	Trust Score*3 stars
FlightHub	Price Accuracy3 stars	Trust Score*1 star
eDreams	Price Accuracy3 stars	Trust Score*3 stars
AranGrant	Price Accuracy2 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 eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on Ontario-London flight deals on Cheapflights vs. eDreams >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 eDreams the most. eDreams 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 $226). Flying from Ontario to London in June is currently the most expensive (average of $563). 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

7.9

Good

7,998 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

7.9

Good

7,998 reviews

Delta

7.9

Good

7,998 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

9,043 reviews

Delta

7.9

Good

7,998 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

11,039 reviews

Delta

7.9

Good

7,998 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

3,033 reviews

Delta

7.9

Good

7,998 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

7,536 reviews

Delta

7.9

Good

7,998 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 6 airlines. Ontario is conveniently located just 3.1 mi from Ontario’s city center.
How long is the flight from Ontario to London?
United Airlines, Delta, and Virgin Atlantic can get you from Ontario to London in just under 14h 07m. Your travel time can differ by up to 9h 48m. 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 Delta is currently your cheapest option to London, with prices starting at $572. Additional round-trip tickets that might be worth considering are offered by KLM and Iberia, with the lowest prices starting at $580 and $615, respectively. You may be able to fly from Ontario to London for 26% 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 United Airlines ($399), Iberia ($546), and Delta ($592).
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 $226). Flying from Ontario to London in June is currently the most expensive (average of $563). 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

Ilford

Hounslow

Hayes

Southend-on-Sea

Harrow

Eastleigh

Dartford

Dover

Winchester

Croydon

Orpington

Watford

Borehamwood

Aylesbury

Chipping Norton

Wembley

Folkestone

Eastbourne

Sutton

Milton Keynes

Browse thousands of different options on Cheapflights for your next trip

Top 6 airlines flying from Ontario to London

Airline	Cheapest	Average	Flexibility	On-time
Delta	Cheapest$570	Average$672	FlexibilityNo cancel fee	On-timeN/A
KLM	Cheapest$580	Average$672	FlexibilityNo cancel fee	On-time75%
Iberia	Cheapest$615	Average$713	FlexibilityNo cancel fee	On-time77%
American Airlines	Cheapest$624	Average$806	FlexibilityNo cancel fee	On-time71%
British Airways	Cheapest$653	Average$862	FlexibilityNo cancel fee	On-time70%
United Airlines	Cheapest$665	Average$815	FlexibilityNo cancel fee	On-time69%

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$339+ 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 12/9. 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 November 25, 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 November 25, 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 November.

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 November 25, 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?

How long is the flight from Ontario to London?

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?

Traveling to a place near London?

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Alternative routes for Ontario to London

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Top 6 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 November 25, 2025.