$290+ 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 9/24. 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
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 September or October, booked 79 days in advance, depart on a Wednesday or Tuesday and return on a Tuesday
Cheap flight deals from Ontario to London
Discover tips and strategies to find the most affordable flight options for your journey from Ontario (ONT) to London (LON). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated June 12, 2025.
Round-trip from | $609 (Delta) |
|---|---|
One-way from | $322 (Trip.com) |
Popular in | June |
Cheapest in | September |
Average price | $1,072 |
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 June 12, 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 June 12, 2025.
This Delta deal was found by Cheapflights users on 6/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
This Iberia deal was found by Cheapflights users on 6/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Iberia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
This Priceline deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
This Expedia deal was found by Cheapflights users on 6/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
This United Airlines deal was found by Cheapflights users on 6/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
This American Airlines deal was found by Cheapflights users on 6/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
This Virgin Atlantic deal was found by Cheapflights users on 6/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Virgin Atlantic is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
This KLM deal was found by Cheapflights users on 6/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
This JetBlue deal was found by Cheapflights users on 6/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure JetBlue is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
This United Airlines deal was found by Cheapflights users on 6/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
This Orbitz deal was found by Cheapflights users on 6/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Orbitz is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
This Air France deal was found by Cheapflights users on 6/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air France is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Cheapflights Fare Finder
Customize your flight search to find flights from Ontario to London that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated June 12, 2025.
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
Tue 7/15
1:15 pm-9:50 am
1 stop12h 35m
London Heathrow
Wed 7/30
5:25 pm-10:25 am
1 stop25h 00m
OntarioLondon
ONT - LHR
ONTLHR
Ontario
Sun 10/5
2:30 pm-2:25 pm
1 stop15h 55m
London Heathrow
Tue 10/14
6:10 am-12:02 am
2 stops25h 52m
OntarioLondon
ONT - LHR
ONTLHR
Ontario
Tue 8/12
2:57 pm-2:25 pm
1 stop15h 28m
London Heathrow
Tue 9/2
11:30 am-10:48 pm
2 stops19h 18m
OntarioLondon
ONT - LHR
ONTLHR
Ontario
Tue 8/12
5:05 am-6:30 am
2 stops17h 25m
London Heathrow
Tue 9/2
5:40 pm-12:32 pm
2 stops26h 52m
OntarioLondon
ONT - LHR
ONTLHR
Ontario
Fri 8/8
6:39 pm-6:30 am
2 stops51h 51m
London Heathrow
Fri 8/22
12:05 pm-12:13 pm
2 stops32h 08m
OntarioLondon
ONT - LHR
ONTLHR
Ontario
Sun 8/3
4:45 pm-12:50 pm
1 stop12h 05m
London Heathrow
Tue 8/19
11:15 am-5:52 pm
1 stop14h 37m
OntarioLondon
ONT - LHR
ONTLHR
Ontario
Mon 8/4
2:14 pm-4:15 pm
2 stops18h 01m
London Heathrow
Tue 8/12
11:20 am-11:40 pm
2 stops20h 20m
OntarioLondon
ONT - LHR
ONTLHR
Ontario
Sun 11/16
12:00 pm-10:35 am
1 stop14h 35m
London Heathrow
Fri 11/28
2:20 pm-10:41 pm
1 stop16h 21m
OntarioLondon
ONT - LHR
ONTLHR
Ontario
Mon 9/8
10:56 pm-8:45 pm
1 stop13h 49m
London Heathrow
Wed 9/17
8:15 am-9:29 pm
1 stop21h 14m
OntarioLondon
ONT - LCY
ONTLCY
Ontario
Thu 9/4
7:05 am-7:15 am
2 stops16h 10m
London City
Thu 9/18
9:20 am-10:41 pm
2 stops21h 21m
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 June 9, 2025.
To ensure you get the cheapest price possible for a flight from Ontario to London, you should look to book at least 78 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 $1,108). 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?
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 June 12, 2025.
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?
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.
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
Plan your trip to London by taking into account the average rainfall totals 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
Plan your trip to London by taking into account the average temperature totals 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 insights into the airlines that provide service to London. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to London. Reviews last updated June 12, 2025.
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.
Food
Boarding
Crew
Entertainment
Comfort
Overall
Reviews
Aaron,Oct 2024
LAX - LHR
Food
Boarding
Crew
Entertainment
Comfort
Overall
Reviews
Aaron,Oct 2024
LAX - LHR
Food
Boarding
Crew
Entertainment
Comfort
Overall
Reviews
Aaron,Oct 2024
LAX - LHR
Food
Boarding
Crew
Entertainment
Comfort
Overall
Reviews
Aaron,Oct 2024
LAX - LHR
Food
Boarding
Crew
Entertainment
Comfort
Overall
Reviews
Aaron,Oct 2024
LAX - LHR
Food
Boarding
Crew
Entertainment
Comfort
Overall
Reviews
Aaron,Oct 2024
LAX - LHR
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.
Traveling to a place near Ontario?
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Alternative routes for Ontario to London
See prices for flight routes from nearby airports that may be better suited for you.
Top 7 airlines flying from Ontario to London
Discover the top 7 airlines that operate flights from Ontario to London. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated June 12, 2025.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$454 | Average$765 | FlexibilityNo cancel fee | On-time72% | |
| Cheapest$582 | Average$670 | FlexibilityNo cancel fee | On-time77% | |
| Cheapest$594 | Average$791 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$608 | Average$763 | FlexibilityNo cancel fee | On-time75% | |
| Cheapest$633 | Average$796 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$647 | Average$820 | FlexibilityNo cancel fee | On-time70% | |
| Cheapest$648 | Average$894 | FlexibilityNo cancel fee | On-time71% |