554 € Cheap Flights from Ontario International to London

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Travellers and cabin class, 1 Adult, Economy

Compare Ontario International to London flight deals

Find the cheapest month or even day of the year to fly to London

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Flight deals from Ontario International to London

Looking for a cheap last-minute deal or the best return flight from Ontario International Airport to London? If you want to travel next month, return fares start from 634 €. Find the lowest prices on one-way and return tickets right here.

London.554 € per passenger.Departing Sun, 8 Nov, returning Fri, 13 Nov.Return flight with Frontier Airlines and Scandinavian Airlines.Outbound indirect flight with Frontier Airlines, departs from Ontario International on Sun, 8 Nov, arriving in London Heathrow.Inbound indirect flight with Scandinavian Airlines, departs from London Heathrow on Fri, 13 Nov, arriving in Ontario International.Price includes taxes and charges.From 554 €, select.

London.634 € per passenger.Departing Tue, 13 Oct, returning Tue, 20 Oct.Return flight with Delta.Outbound indirect flight with Delta, departs from Ontario International on Tue, 13 Oct, arriving in London Heathrow.Inbound indirect flight with Delta, departs from London Gatwick on Tue, 20 Oct, arriving in Ontario International.Price includes taxes and charges.From 634 €, select.

London.635 € per passenger.Departing Wed, 25 Nov, returning Thu, 3 Dec.Return flight with Delta.Outbound indirect flight with Delta, departs from Ontario International on Wed, 25 Nov, arriving in London Heathrow.Inbound indirect flight with Delta, departs from London Heathrow on Thu, 3 Dec, arriving in Ontario International.Price includes taxes and charges.From 635 €, select.

London.636 € per passenger.Departing Tue, 27 Oct, returning Tue, 3 Nov.Return flight with Delta.Outbound indirect flight with Delta, departs from Ontario International on Tue, 27 Oct, arriving in London Heathrow.Inbound indirect flight with Delta, departs from London Heathrow on Tue, 3 Nov, arriving in Ontario International.Price includes taxes and charges.From 636 €, select.

London.636 € per passenger.Departing Wed, 2 Dec, returning Wed, 9 Dec.Return flight with Delta.Outbound indirect flight with Delta, departs from Ontario International on Wed, 2 Dec, arriving in London Heathrow.Inbound indirect flight with Delta, departs from London Gatwick on Wed, 9 Dec, arriving in Ontario International.Price includes taxes and charges.From 636 €, select.

London.639 € per passenger.Departing Mon, 5 Apr, returning Wed, 14 Apr.Return flight with Air France and KLM.Outbound indirect flight with Air France, departs from Ontario International on Mon, 5 Apr, arriving in London Heathrow.Inbound indirect flight with KLM, departs from London Heathrow on Wed, 14 Apr, arriving in Ontario International.Price includes taxes and charges.From 639 €, select.

London.644 € per passenger.Departing Tue, 12 Jan, returning Wed, 10 Feb.Return flight with Delta.Outbound indirect flight with Delta, departs from Ontario International on Tue, 12 Jan, arriving in London Heathrow.Inbound indirect flight with Delta, departs from London Gatwick on Wed, 10 Feb, arriving in Ontario International.Price includes taxes and charges.From 644 €, select.

London.647 € per passenger.Departing Wed, 3 Feb, returning Wed, 17 Feb.Return flight with Delta.Outbound indirect flight with Delta, departs from Ontario International on Wed, 3 Feb, arriving in London Heathrow.Inbound indirect flight with Delta, departs from London Heathrow on Wed, 17 Feb, arriving in Ontario International.Price includes taxes and charges.From 647 €, select.

London.653 € per passenger.Departing Sat, 9 Jan, returning Wed, 20 Jan.Return flight with Delta.Outbound indirect flight with Delta, departs from Ontario International on Sat, 9 Jan, arriving in London Heathrow.Inbound indirect flight with Delta, departs from London Gatwick on Wed, 20 Jan, arriving in Ontario International.Price includes taxes and charges.From 653 €, select.

London.656 € per passenger.Departing Sun, 27 Sep, returning Tue, 13 Oct.Return flight with Alaska Airlines.Outbound indirect flight with Alaska Airlines, departs from Ontario International on Sun, 27 Sep, arriving in London Heathrow.Inbound indirect flight with Alaska Airlines, departs from London Heathrow on Tue, 13 Oct, arriving in Ontario International.Price includes taxes and charges.From 656 €, select.

London.662 € per passenger.Departing Fri, 25 Sep, returning Wed, 30 Sep.Return flight with Alaska Airlines.Outbound indirect flight with Alaska Airlines, departs from Ontario International on Fri, 25 Sep, arriving in London Heathrow.Inbound indirect flight with Alaska Airlines, departs from London Heathrow on Wed, 30 Sep, arriving in Ontario International.Price includes taxes and charges.From 662 €, select.

London.679 € per passenger.Departing Thu, 15 Oct, returning Thu, 4 Feb.Return flight with Delta.Outbound indirect flight with Delta, departs from Ontario International on Thu, 15 Oct, arriving in London Heathrow.Inbound indirect flight with Delta, departs from London Heathrow on Thu, 4 Feb, arriving in Ontario International.Price includes taxes and charges.From 679 €, select.

London.689 € per passenger.Departing Sun, 25 Oct, returning Sun, 7 Mar.Return flight with Delta.Outbound indirect flight with Delta, departs from Ontario International on Sun, 25 Oct, arriving in London Heathrow.Inbound indirect flight with Delta, departs from London Heathrow on Sun, 7 Mar, arriving in Ontario International.Price includes taxes and charges.From 689 €, select.

London.699 € per passenger.Departing Tue, 18 May, returning Tue, 25 May.Return flight with Virgin Atlantic.Outbound indirect flight with Virgin Atlantic, departs from Ontario International on Tue, 18 May, arriving in London Heathrow.Inbound indirect flight with Virgin Atlantic, departs from London Heathrow on Tue, 25 May, arriving in Ontario International.Price includes taxes and charges.From 699 €, select.

London.720 € per passenger.Departing Tue, 1 Dec, returning Sat, 9 Jan.Return flight with Delta.Outbound indirect flight with Delta, departs from Ontario International on Tue, 1 Dec, arriving in London Heathrow.Inbound indirect flight with Delta, departs from London Heathrow on Sat, 9 Jan, arriving in Ontario International.Price includes taxes and charges.From 720 €, select.

London.738 € per passenger.Departing Thu, 25 Mar, returning Sat, 3 Apr.Return flight with Delta.Outbound indirect flight with Delta, departs from Ontario International on Thu, 25 Mar, arriving in London Heathrow.Inbound indirect flight with Delta, departs from London Heathrow on Sat, 3 Apr, arriving in Ontario International.Price includes taxes and charges.From 738 €, select.

Find the cheapest month to fly from Ontario International to London

We’re always keeping an eye on fares, so you can find the best one in seconds. It looks like Ontario International to London flights are currently cheapest in November.

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Alternative Ontario International to London routes

Looking for the cheapest, fastest or easiest route from Ontario International to London? You could fly into the following airports instead.

Ontario to London: Flight information

The things to know before you go.

Cheapest flight found	554 €
Cheapest month to fly	November

Finding cheap flights from Ontario International to London: Frequently asked questions

How many airports are there in London?

There are 6 airports in London: London City, London Heathrow, London Gatwick, London Luton, London Stansted, and London Southend.

How much are return flights from Ontario International to London?

The best price we found for a return flight from Ontario International to London is 554 €. This is an estimate based on information collected from different airlines and travel providers over the last 4 days and is subject to change and availability.

Which airlines fly direct from Ontario International to London?

Currently, there are no airlines that fly direct from Ontario International to London. But we found flights with one or more stops from 554 €.

How many flights are there a week from Ontario International to London?

As of September 2026, there are no flights flying from Ontario International to London.

When is the cheapest time to fly from Ontario International to London?

The cheapest month to fly from Ontario International to London is usually November.

Which is the cheapest airport to fly into in London?

If you're flying from Ontario International Airport, the cheapest airport near London is London Heathrow – which is 22.9 km away from the centre of London. We've found flights into this airport from 554 €.

Which upcoming date is cheapest to fly from Ontario International Airport to London on?

After crunching the numbers on our flight calendar, we found that it's currently cheapest to fly from Ontario International Airport to London on Sunday, 8 November 2026.

Can I get a direct flight from Ontario International Airport to London?

No airlines currently offer direct flights between Ontario International Airport and London. Most routes have one or more stops.

How can I get the best flight deal from Ontario International Airport to London?

We show every price from over 1,200 airlines and travel agents, comparing them all so you don’t have to. If you know you want to fly to London but you’re not ready to book, set up a Price Alert. We’ll track prices for you, and let you know when they rise or fall.

When is the best time to book flights to London?

We crunched all the numbers in our flight calendar and it looks like the cheapest time to book a flight to London is around 40 days in advance, so don’t leave your flight to the last minute.

What’s the weather like in London?

In September, the average temperature is usually around 16°C. July is typically the warmest month in London, when it usually averages around 23°C. You can expect the least rain in April. The coldest month is January, with temperatures averaging 2°C. The rainiest month is October.

Which is the cheapest airline to fly from Ontario International Airport to London with?

Currently, Frontier Airlines offers the cheapest flight tickets to London.

Flying from Ontario International Airport (ONT) to London: what you need to know

The timezone in London is UTC+0. The city is eight hours ahead of Ontario, where Ontario International Airport is located.
For a smooth journey, turn up at the airport two hours ahead of international flights and one hour before domestic departures. This ensures you have enough time to board your ONT to London flight.
Be prepared for longer lines in popular months such as July. Arriving up to four hours ahead of an international flight and two hours for domestic departures is a wise move.
Consider adding a stopover to potentially find a cheaper plane ticket from ONT to London. Simply uncheck 'Direct flights only' during your search. Break up your trip (and maybe save some cash) by stopping at one of these popular options:
- Denver International Airport (DEN)
- Phoenix Sky Harbour International Airport (PHX)
- Las Vegas Harry Reid International Airport (LAS)
ONT is around 5 kilometres from central Ontario. If you're catching a taxi, driving or ride-sharing from the centre, it'll take 15 minutes or so to get there, depending on the traffic. If you're planning to take public transport, expect the trip time to be around 45 minutes.
In search of a hotel near ONT? If you've booked an early flight from Ontario International Airport to London, these accommodation options set you up for a seamless send-off:
83% of flights leaving Ontario International Airport reach their destination according to schedule. Given its strong performance rating, disruptions are unlikely when taking off from ONT.
You'll find ONT at 2900 E. Airport Drive.

How to find the cheapest flights from Ontario International Airport (ONT) to London

280 € is the cheapest price we've seen for a one-way Ontario International Airport to London flight. A round-trip plane ticket right now is 554 €. Depending on the availability and when you book, these fares may change.
To find cheap flights from ONT to London, book as early as you can. Airlines typically offer the most competitive fares when flights first go on sale.
Finding cheap tickets from Ontario International Airport to London is easier if you're flexible with your trip dates. Use the 'Whole month' function to get the best prices across the month and score an awesome deal.
Snapping up a cheap flight from ONT to London is easy with Price Alerts. All you need to do is set up one of these automatic notifications and we'll get in touch when a new discount appears.
Choose your preferred arrival and departure times, airlines and number of stops with our filters. Then, sort the results for your flight from Ontario International Airport to London by 'Cheapest,' 'Best' or 'Fastest.'

Airports in London

London Heathrow Airport (LHR)

London Heathrow Airport (LHR) to the centre of London takes around 45 minutes to reach by car. The centre is roughly 24 kilometres away.
Getting to the centre by public transport takes about 25 minutes.
The last thing you need is a long journey to your hotel if you're landing late on a flight from Ontario International Airport to London. Reserve one of these accommodation options near LHR instead:
Secure the lowest price by reserving your ride from London Heathrow Airport about one week in advance of your flight from ONT to London.

London Gatwick Airport (LGW)

After your flight from Ontario International Airport to London has landed, you can get to the city centre in around 1 hour 5 minutes by car. Central London is roughly 48 kilometres from London Gatwick Airport (LGW).
You can expect the journey to take about 1 hour 20 minutes on public transport.
After stepping off your ONT to London flight, settle in at a hotel close to LGW. These are some comfortable accommodation options that'll help you slip into relaxation mode:
Get the pick of the lot. Booking your ride from LGW three weeks in advance often means more savings and a greater range of vehicles.

London Stansted Airport (STN)

Set your sights on the city centre after your flight from Ontario International Airport to London has touched down. Central London is about 56 kilometres from London Stansted Airport (STN) and takes roughly 1 hour 5 minutes to reach by taxi or ride-share.
If you travel by public transport, expect a journey of about 45 minutes.
Enjoy a quiet, low-key start to your trip by choosing a hotel near STN after your ONT to London flight. Recover from your travel day or simply take a moment to get your bearings in a new destination at:
About four weeks ahead of your flight from Ontario International Airport to London is a good time to secure your ride from STN. You're likely to snag a better deal or catch some early booking discounts.

Best time to go to London

It's time to plan your dates for your flight from Ontario International Airport to London. July is the busiest month for a trip to London. If you want a more low-key vibe, go in January.
The warmest month in London is July, with temperatures ranging between 11ºC (52ºF) and 26ºC (79ºF). Book your Ontario International Airport to London plane ticket then if this is the type of weather you enjoy.
For cooler conditions, look for a cheap ticket from ONT to London in January when temperatures average between 0ºC (32ºF) and 9ºC (48ºF).

More about London

After booking your flight from Ontario International Airport to London, find a hotel that keeps you close to what you want to see. Make one of these options your base for exploring London:
All great journeys should include a little sightseeing. Westminster Abbey, The British Museum and Big Ben are essential stops on your London itinerary.

Explore more of the United Kingdom

You've seen London, now it's time to discover more of the United Kingdom. Journey about 257 kilometres northwest to Manchester to check off its popular sights. From Manchester United Museum & Stadium Tour to The Homes of Football and Museum of Science and Industry, you've got a jam-packed schedule ahead.
Around 161 kilometres northwest of London, Birmingham is another essential stop in the United Kingdom. No visit is complete without checking out Birmingham Museum & Art Gallery, Birmingham Hippodrome Theatre and Bournville Experience.

Plan the rest of your trip from Ontario to London

Prices shown on this page are estimated lowest prices only. Found in the last 12 days.