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

Flying on Iberia is currently your cheapest option to London, with prices starting at $619. Additional round-trip tickets that might be worth considering are offered by KLM and British Airways, with the lowest prices starting at $620 and $638, respectively. You may be able to fly from Ontario to London for 18% 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 British Airways ($393), JetBlue ($394), and KLM ($423).

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: American Airlines, British Airways or Delta.

What is the cheapest day to fly round-trip from Ontario to London?

Friday flights are found to be more expensive to fly from Ontario to London. This shouldn’t discourage you from searching, as you can still find great deals by being flexible with your options. Use our search form to find deals on tickets to London.

How far in advance should I book a flight from Ontario to London?

To save on the cost of your flight from Ontario to London, book at least 54 days before your planned departure. Booking around this time can save you about 9% on the cost of this flight compared to booking a flight leaving this week. We have found prices from $715 if you need a flight within two weeks. For flights within the next 72 hours, you can find tickets from as low as $959.

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

Our data shows that October tends to be the cheapest month to fly to London from Ontario. Users have commonly found prices around $746 for the month, but tickets can be as low as $440. Due to multiple factors, prepare for potentially higher prices in June.

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.

$269+ Save on Flights from Ontario to London

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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.

Cheapflights Tip: The best prices from Ontario to London are usually found in October or May, booked 74 days in advance, depart on a Wednesday or Tuesday and return on a Tuesday

Cheap flight deals from Ontario to London

Most accurate provider	FlightHub 3 stars
Most trusted provider	FlightHub 3 stars
Round-trip from	$619 (Iberia)
One-way from	$285 (Kiwi.com)
Popular in	June
Cheapest in	October
Average price	$801

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. 11% potential increase in price ($98 potential increase over avg. RT price).

Search Deals

Cheapest flight prices on average. 4% potential price decrease ($32 potential savings vs. average RT price).

Search Deals

Average for round-trip flights in March 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 March 25, 2025.

Mon 4/712:50 pmONT - LHR

1 stop14h 00mIberia

Tue 4/223:10 pmLHR - ONT

1 stop15h 00mIberia

Deal found 3/24

$619

Mon 4/712:42 pmONT - LHR

1 stop14h 28mKLM

Tue 4/2211:20 amLHR - ONT

1 stop16h 08mKLM

Deal found 3/24

$620

Mon 4/74:35 pmONT - LHR

1 stop12h 15mBritish Airways

Tue 4/223:10 pmLHR - ONT

1 stop15h 00mBritish Airways

Deal found 3/24

$638

Mon 4/71:30 pmONT - LHR

1 stop12h 20mDelta

Tue 4/2210:55 amLHR - ONT

1 stop13h 38mDelta

Deal found 3/24

$642

Mon 4/712:42 pmONT - LHR

1 stop14h 28mVirgin Atlantic

Mon 4/147:45 pmLHR - ONT

2 stops28h 48mVirgin Atlantic

Deal found 3/24

$657

Thu 12/2511:00 amONT - LHR

1 stop13h 15mMultiple Airlines

Fri 1/910:40 amLHR - ONT

1 stop19h 22mMultiple Airlines

Deal found 3/24

$669

Fri 5/24:15 pmONT - LHR

2 stops54h 15mAir Canada

Wed 5/149:30 amLHR - ONT

2 stops19h 23mAir Canada

Deal found 3/24

$675

Wed 4/231:35 pmONT - LHR

1 stop12h 05mUnited Airlines

Wed 4/302:50 pmLHR - ONT

1 stop13h 52mUnited Airlines

Deal found 3/24

$684

Sat 5/310:40 pmONT - LHR

1 stop14h 05mJetBlue

Sat 5/178:15 amLHR - ONT

1 stop20h 56mJetBlue

Deal found 3/23

$744

Wed 5/75:05 amONT - LCY

2 stops27h 20mMultiple Airlines

Fri 5/168:55 amLCY - ONT

2 stops21h 05mMultiple Airlines

Deal found 3/23

$753

Mon 4/74:35 pmONT - LHR

1 stop12h 15mAmerican Airlines

Tue 4/223:40 pmLHR - ONT

1 stop14h 18mAmerican Airlines

Deal found 3/24

$806

Sun 5/1110:59 pmONT - LHR

1 stop26h 31mIcelandair

Thu 5/228:15 amLHR - ONT

1 stop20h 56mIcelandair

Deal found 3/24

$828

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 March 25, 2025.

Mon 4/712:50 pmONT - LHR

1 stop14h 00mIberia

Tue 4/223:10 pmLHR - ONT

1 stop15h 00mIberia

Deal found 3/24

$619

Mon 4/712:42 pmONT - LHR

1 stop14h 28mKLM

Tue 4/2211:20 amLHR - ONT

1 stop16h 08mKLM

Deal found 3/24

$620

Mon 4/74:35 pmONT - LHR

1 stop12h 15mBritish Airways

Tue 4/223:10 pmLHR - ONT

1 stop15h 00mBritish Airways

Deal found 3/24

$638

Mon 4/71:30 pmONT - LHR

1 stop12h 20mDelta

Tue 4/2210:55 amLHR - ONT

1 stop13h 38mDelta

Deal found 3/24

$642

Mon 4/712:42 pmONT - LHR

1 stop14h 28mVirgin Atlantic

Mon 4/147:45 pmLHR - ONT

2 stops28h 48mVirgin Atlantic

Deal found 3/24

$657

Fri 5/24:15 pmONT - LHR

2 stops54h 15mAir Canada

Wed 5/149:30 amLHR - ONT

2 stops19h 23mAir Canada

Deal found 3/24

$675

Wed 4/231:35 pmONT - LHR

1 stop12h 05mUnited Airlines

Wed 4/302:50 pmLHR - ONT

1 stop13h 52mUnited Airlines

Deal found 3/24

$684

Sat 5/310:40 pmONT - LHR

1 stop14h 05mJetBlue

Sun 5/118:15 amLHR - ONT

1 stop20h 56mJetBlue

Deal found 3/24

$744

Mon 4/74:35 pmONT - LHR

1 stop12h 15mAmerican Airlines

Tue 4/223:40 pmLHR - ONT

1 stop14h 18mAmerican Airlines

Deal found 3/24

$806

Sun 5/1110:59 pmONT - LHR

1 stop26h 31mIcelandair

Thu 5/228:15 amLHR - ONT

1 stop20h 56mIcelandair

Deal found 3/24

$828

Tue 4/225:00 amONT - LHR

2 stops17h 30mMultiple Airlines

Sun 4/278:30 amLHR - ONT

2 stops22h 25mMultiple Airlines

Deal found 3/24

$855

Thu 4/243:55 pmONT - LCY

2 stops18h 40mMultiple Airlines

Wed 4/308:45 amLCY - ONT

2 stops21h 13mMultiple Airlines

Deal found 3/23

$883

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

Sun 3/3012:46 pmONT - LHR

1 stop16h 44mDelta

Fri 4/111:25 pmLHR - ONT

1 stop16h 59mDelta

Deal found 3/24

$9,446

Sun 3/3012:10 amONT - LHR

1 stop32h 20mChina Airlines

Mon 4/79:10 pmLHR - ONT

1 stop28h 50mChina Airlines

Deal found 3/24

$9,753

Mon 3/312:54 pmONT - LHR

1 stop13h 36mBritish Airways

Mon 4/73:10 pmLHR - ONT

1 stop16h 40mBritish Airways

Deal found 3/24

$1,026

Mon 3/314:30 pmONT - LHR

1 stop12h 20mAmerican Airlines

Mon 4/143:40 pmLHR - ONT

1 stop14h 18mAmerican Airlines

Deal found 3/24

$1,249

Mon 3/3110:57 amONT - LHR

1 stop14h 03mIberia

Mon 4/143:10 pmLHR - ONT

1 stop16h 40mIberia

Deal found 3/24

$1,261

Mon 3/314:30 pmONT - LHR

1 stop12h 20mMultiple Airlines

Mon 4/1410:05 pmLHR - ONT

2 stops31h 50mMultiple Airlines

Deal found 3/24

$1,518

Mon 3/317:17 pmONT - LGW

2 stops32h 28mMultiple Airlines

Mon 4/71:00 pmLGW - ONT

2 stops18h 59mMultiple Airlines

Deal found 3/24

$2,154

Tue 4/11:35 pmONT - LHR

1 stop12h 05mUnited Airlines

Fri 4/112:50 pmLHR - ONT

1 stop13h 52mUnited Airlines

Deal found 3/23

$983

Tue 4/111:25 pmONT - LHR

2 stops32h 10mAvianca

Mon 4/710:05 pmLHR - ONT

2 stops31h 50mAvianca

Deal found 3/24

$1,831

Wed 4/21:30 pmONT - LHR

1 stop12h 20mKLM

Wed 4/1611:00 amLHR - ONT

1 stop13h 33mKLM

Deal found 3/24

$1,223

Sat 4/55:00 amONT - LHR

2 stops21h 00mAir Canada

Fri 4/119:30 amLHR - ONT

2 stops35h 08mAir Canada

Deal found 3/23

$1,132

Mon 4/712:50 pmONT - LHR

1 stop14h 00mIberia

Tue 4/223:10 pmLHR - ONT

1 stop15h 00mIberia

Deal found 3/24

$619

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 March 25, 2025.

Sun 4/62:48 pmONT - LGW

2 stops35h 12mMultiple Airlines

Deal found 3/24

$285

Sun 5/44:35 pmONT - LHR

1 stop14h 05mBritish Airways

Deal found 3/24

$393

Wed 4/3010:40 pmONT - LHR

1 stop14h 05mJetBlue

Deal found 3/24

$394

Wed 4/236:00 amONT - LHR

3 stops54h 55mMultiple Airlines

Deal found 3/24

$404

Sun 4/2712:07 pmONT - LHR

1 stop15h 03mKLM

Deal found 3/24

$423

Sun 9/216:36 pmONT - LHR

2 stops33h 14mUnited Airlines

Deal found 3/24

$425

Sat 4/1210:54 amONT - LHR

1 stop14h 06mIberia

Deal found 3/24

$451

Wed 4/237:00 amONT - LCY

2 stops17h 50mDelta

Deal found 3/24

$461

Sat 5/105:05 amONT - LHR

2 stops20h 55mAir Canada

Deal found 3/24

$463

Sun 5/47:00 amONT - LCY

2 stops23h 20mBritish Airways

Deal found 3/24

$471

Sun 4/62:48 pmONT - LCY

3 stops42h 27mMultiple Airlines

Deal found 3/24

$508

Wed 4/236:00 amONT - SEN

3 stops30h 50mMultiple Airlines

Deal found 3/24

$602

Cheapflights Fare Finder

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

Fly from

Fly to

Route

Depart

Return

Price

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 4/7

12:50 pm-10:50 am

1 stop14h 00m

London Heathrow

Tue 4/22

4:25 pm-11:50 pm

1 stop15h 25m

$619

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 4/7

12:42 pm-11:10 am

1 stop14h 28m

London Heathrow

Tue 4/22

11:20 am-7:28 pm

1 stop16h 08m

$620

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 4/7

4:35 pm-12:50 pm

1 stop12h 15m

London Heathrow

Tue 4/22

3:10 pm-10:10 pm

1 stop15h 00m

$638

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 4/7

1:30 pm-9:50 am

1 stop12h 20m

London Heathrow

Tue 4/22

10:55 am-4:33 pm

1 stop13h 38m

$642

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 4/7

12:42 pm-11:10 am

1 stop14h 28m

London Heathrow

Mon 4/14

7:45 pm-4:33 pm

2 stops28h 48m

$657

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Fri 5/2

4:15 pm-6:30 am

2 stops54h 15m

London Heathrow

Wed 5/14

9:30 am-8:53 pm

2 stops19h 23m

$675

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Wed 4/23

1:35 pm-9:40 am

1 stop12h 05m

London Heathrow

Wed 4/30

2:50 pm-8:42 pm

1 stop13h 52m

$684

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sat 5/3

10:40 pm-8:45 pm

1 stop14h 05m

London Heathrow

Sat 5/17

8:15 am-9:11 pm

1 stop20h 56m

$744

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Mon 4/7

4:35 pm-12:50 pm

1 stop12h 15m

London Heathrow

Tue 4/22

3:40 pm-9:58 pm

1 stop14h 18m

$806

OntarioLondon

ONT - LHR

ONTLHR

Ontario

Sun 5/11

10:59 pm-9:30 am

1 stop26h 31m

London Heathrow

Thu 5/22

8:15 am-9:11 pm

1 stop20h 56m

$828

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/24

Showing 1-10 of 37 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 March.

Provider	Price Accuracy	Trust Score*
Expedia	Price Accuracy1 star	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*1 star

*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

How far ahead should I book a flight from Ontario to London?

To ensure you get the cheapest price possible for a flight from Ontario to London, you should look to book at least 72 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

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

Currently, November is the cheapest month in which you can book a flight from Ontario to London (average of $661). Flying from Ontario to London in June is currently the most expensive (average of $1,115). 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 evening. By choosing this option you can save up to 24% on the cost of your flight, compared to a flight in the morning.

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 afternoons 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.

Rainfall in London by month

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.

Temperature in London by month

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).

Reviews of airlines servicing London

Get a feel of what it's like to fly with Delta, KLM and United Airlines from Ontario to London by reading reviews from past customers. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.

Delta

8.0

Very good

7,890 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

7,890 reviews

Delta

8.0

Very good

7,890 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.

KLM

7.8

Good

1,318 reviews

Delta

8.0

Very good

7,890 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

8,605 reviews

Delta

8.0

Very good

7,890 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.

Virgin Atlantic

7.4

Good

634 reviews

Delta

8.0

Very good

7,890 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.

JetBlue

7.3

Good

2,924 reviews

Delta

8.0

Very good

7,890 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.
What are the cheapest airlines flying from Ontario to London round-trip?
Flying on Iberia is currently your cheapest option to London, with prices starting at $619. Additional round-trip tickets that might be worth considering are offered by KLM and British Airways, with the lowest prices starting at $620 and $638, respectively. You may be able to fly from Ontario to London for 18% 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 British Airways ($393), JetBlue ($394), and KLM ($423).
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, November is the cheapest month in which you can book a flight from Ontario to London (average of $661). Flying from Ontario to London in June is currently the most expensive (average of $1,115). 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

Thornton Heath

Luton

Wembley

Harrow

Horley

Canterbury

Gatwick

Dover

Orpington

Watford

Milton Keynes

Croydon

Borehamwood

Bromley

Folkestone

Ilford

Aylesbury

Sutton

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$454	Average$889	FlexibilityNo cancel fee	On-time72%
KLM	Cheapest$481	Average$763	FlexibilityNo cancel fee	On-time75%
Delta	Cheapest$482	Average$711	FlexibilityNo cancel fee	On-timeN/A
Iberia	Cheapest$582	Average$663	FlexibilityNo cancel fee	On-time77%
United Airlines	Cheapest$619	Average$740	FlexibilityNo cancel fee	On-time69%
American Airlines	Cheapest$629	Average$894	FlexibilityNo cancel fee	On-time71%
British Airways	Cheapest$648	Average$843	FlexibilityNo cancel fee	On-time70%

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$269+ 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 4/2. Fares are subject to change and may not be available on all flights or dates of travel.

Find cheap flights from Ontario to London with Cheapflights

1. Tell us where you want to go

2. Select your favorite providers

3. Compare prices and book

Cheapflights Tip: The best prices from Ontario to London are usually found in October or May, booked 74 days in advance, depart on a Wednesday or Tuesday and return on a Tuesday

Cheap flight deals from Ontario to London

Most accurate provider

Most trusted provider

Round-trip from

One-way from

Popular in

Cheapest in

Average price

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 March 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 March 25, 2025.

Cheapflights Fare Finder

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 March.

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

How far ahead should I book a flight from Ontario to London?

Use this chart to determine the optimal time to book a round-trip flight from Ontario to London. Price data was last updated on March 21, 2025.

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 March 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.

Rainfall in London by month

Plan your trip to London by taking into account the average rainfall totals by month.

Temperature in London by month

Plan your trip to London by taking into account the average temperature totals by month.

Reviews of airlines servicing London

Get a feel of what it's like to fly with Delta, KLM and United Airlines from Ontario to London by reading reviews from past customers. Reviews also offer insight into each airline's 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?

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 March 25, 2025.