Cheap flights from Ontario to London from $311
This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Ontario to London departing on 3/7. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Fly from
Fly to
Route
Depart
Return
OntarioLondon
ONT Ontario - LHR London Heathrow
ONTLHR
Ontario
Tue 3/2
6:35 pm-7:25 am
1 stop28h 50m
London Heathrow
Fri 3/5
6:50 am-6:44 pm
2 stops19h 54m
OntarioLondon
ONT Ontario - LHR London Heathrow
ONTLHR
Ontario
Tue 3/2
1:00 pm-7:40 am
2 stops34h 40m
London Heathrow
Fri 3/5
6:50 am-6:44 pm
2 stops19h 54m
OntarioLondon
ONT Ontario - LHR London Heathrow
ONTLHR
Ontario
Wed 11/4
6:30 am-7:30 pm
2 stops29h 00m
London Heathrow
Mon 11/9
12:15 pm-11:51 pm
2 stops19h 36m
OntarioLondon
ONT Ontario - LHR London Heathrow
ONTLHR
Ontario
Tue 2/2
7:00 am-12:20 pm
1 stop21h 20m
London Heathrow
Tue 2/9
2:45 pm-10:41 pm
1 stop15h 56m
OntarioLondon
ONT Ontario - LHR London Heathrow
ONTLHR
Ontario
Mon 1/11
7:00 am-12:20 pm
1 stop21h 20m
London Heathrow
Fri 1/22
2:45 pm-10:41 pm
1 stop15h 56m
OntarioLondon
ONT Ontario - LHR London Heathrow
ONTLHR
Ontario
Tue 3/9
12:49 pm-10:00 am
1 stop13h 11m
London Heathrow
Tue 3/16
2:45 pm-10:39 pm
1 stop14h 54m
OntarioLondon
ONT Ontario - LHR London Heathrow
ONTLHR
Ontario
Wed 1/13
4:19 pm-1:35 pm
1 stop13h 16m
London Heathrow
Sat 1/23
11:15 am-6:51 pm
1 stop15h 36m
OntarioLondon
ONT Ontario - LHR London Heathrow
ONTLHR
Ontario
Mon 3/8
12:49 pm-10:00 am
1 stop13h 11m
London Heathrow
Tue 3/23
1:50 pm-10:25 pm
1 stop15h 35m
OntarioLondon
ONT Ontario - LHR London Heathrow
ONTLHR
Ontario
Sun 1/10
7:00 am-6:25 am
1 stop15h 25m
London Heathrow
Wed 1/13
10:45 am-4:12 pm
1 stop13h 27m
OntarioLondon
ONT Ontario - LHR London Heathrow
ONTLHR
Ontario
Sun 10/25
7:07 am-9:00 am
1 stop18h 53m
London Heathrow
Fri 10/30
12:20 pm-10:43 pm
1 stop17h 23m
See travel insights to London from
How to get the cheapest flight ticket from Ontario to London
Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip
What is the cheapest month to fly to London?
The cheapest month to fly to London from Ontario is in January. Flight prices, which tend to average around $688, are often lower during this time because this is during the off-season. The month of December is another great option to travel to London, with average flight prices from Ontario averaging around $739.
What is the cheapest day to depart on your flight to London?
The cheapest day to depart from Ontario to London is on a Wednesday. Travelers who choose to depart for London on a Wednesday will often find tickets for as low as $930. If your travel schedule is flexible, try to avoid departing on a Saturday because tickets tend to average around $1,033. These prices are subject to change though, so be sure to set up a Price Alert for flights to London.
What is the cheapest time of day to depart on your flight to London?
Flying to London from Ontario at noon is the least expensive time of day to depart. momondo users have found prices as low as $820 when looking at flights departing at noon. Flights to London are more costly in the afternoon, with an average ticket price of $994. Departure times in the afternoon fall within the peak daily travel times, which is why tickets can be more expensive.
Can stopping save me money on Ontario to London flights?
You could potentially save up to 56% on your flight if you consider stops on a Ontario to London flight.
What is the cheapest airline that flies from Ontario to London?
JetBlue and United Airlines are the most popular carriers operating from Ontario to London
What airlines fly to London?
British Airways, Virgin Atlantic and United Airlines are the top three most popular airlines that fly to London from Ontario according to our data. British Airways is the first choice among our users, with 44% of people opting to fly with this airline when traveling to London. Keep in mind that there are 24 different airlines that fly to London on a routine basis, so you have a few additional options to choose from.
Which airport is the most popular layover for flights between Ontario and London?
Denver (DEN) was the most common stop: 40% of momondo users choosing 1-stop flights on this route connected there.
Which layover airport offers the lowest fares from Ontario to London?
Flights via San Francisco (SFO) offer the lowest average round-trip price of $725.
Which layover airport has the shortest travel time from Ontario to London?
Flights connecting via Denver (DEN) have the shortest average one-way travel time: 12h 31m.
Which layover airport has the shortest connection time from Ontario to London?
Denver (DEN) has the shortest average layover time for this route: 1h 22m.
When to book flights from Ontario to London
Cheap Ontario to London (ONT to LON) flight deals and tips
Find info about flight duration, direct flights, and airports for your flight from Ontario to London
Frequently asked questions about flying from Ontario to London
How far is Ontario to London by plane?
The straight-line distance from Ontario to London is 5417.5 mi. A reasonable flight in good conditions will take 12h 00m.
When did momondo last update prices for flights from Ontario Airport to London?
Prices for flights from Ontario Airport to London are updated daily.
How many operators does momondo search for flights from Ontario Airport to London?
As of October 2026, there are 5 operators available to choose from for flights from Ontario Airport to London.
How old do you have to be to fly from Ontario Airport to London?
The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Ontario Airport to London.
What documentation or ID do you need to fly to London?
The necessary travel and health documents for your London trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.
What is the most popular airline from Ontario to London?
momondo data reveals that the most frequently booked airline on the route from Ontario to London is United Airlines, representing 47% of all bookings. The subsequent popular airlines are British Airways at 28% and Virgin Atlantic at 25%.
Best airlines flying from Ontario to London
Compare and see reviews for airlines that fly from Ontario to London with momondo
| Airline | Rating | Free Cancellation | Price | ||
|---|---|---|---|---|---|
| PriceFrom $488 | Free Cancellation | Rating 7.4 693 reviews | |||
| PriceFrom $615 | Free Cancellation | Rating 6.7 8,244 reviews | |||
| PriceFrom $703 | Free Cancellation | Rating 7.4 10,283 reviews | |||
| PriceFrom $710 | Free Cancellation | Rating 7.8 8,628 reviews | |||
| PriceFrom $806 | Free Cancellation | Rating 7.9 13,015 reviews |
Traveling to a place near London?
Book flights to London if you plan to visit one of these locationsWhy use momondo?
Why should I use momondo to find a flight deal from Ontario to London?
momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from Ontario to London. Millions of users trust and use momondo every year so you are in good hands.
Can I find flights from Ontario to London with flexible booking policies on momondo?
All flight searches from Ontario to London on momondo can be filtered to show those which offer flexible booking policies.
How can momondo help me find flights from Ontario to London?
momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from Ontario to London.
I’m not ready to book a flight from Ontario to London right now. Can momondo alert me if prices change?
Yes. momondo can track prices for Ontario to London flights and alert you when they change. Perform a search to set up the price alert. All that is required is a valid email address.