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£45+ Cheap flights from Ontario

This is the cheapest return flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 2/2. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
ONT — LHR
12 Feb — 19 Feb1
1 adult
1 adult, Economy, 0 bags

What to know about flights from Ontario

Discover essential information about flights departing from Ontario, including flight schedules, destinations, airlines operating at the Ontario airport, and any specific guidelines or requirements for travellers. Please note that the information is based on the most recent updates available. Data last updated 13 January 2026.

Cheapest one-way flight

£20

Cheapest round-trip flight

£37

Cheapest airline

Alaska Airlines

Most popular destination

London Heathrow (LHR)

Good round-trip deal

£64 or less

Good one-way deal

£332 or less
The cheapest one-way flight from Ontario is currently to Las Vegas Harry Reid Intl.
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The cheapest round-trip flight from Ontario is currently to Las Vegas Harry Reid Intl.
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On average, Alaska Airlines currently has the cheapest one-way flight from Ontario (avg. price of £87).
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London Heathrow (LHR) is currently the most popular flight destination from Ontario (average return price of £457).
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Price to beat on a round-trip flight from Ontario.
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Price to beat on a one-way flight from Ontario.
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Find flights from Ontario

Enter your travel dates to find the best prices.

Cheapest flights from Ontario
Explore the most affordable flight options available from Ontario. Find the lowest fares based on data from user searches, with prices last updated on 13 January 2026.

Sat 28/216:05
ONT
-
SEA
1 stop6h 05m
Southwest
Sun 1/305:50
SEA
-
ONT
1 stop5h 45m
Southwest
Deal found 12/1£112
Wed 4/214:25
ONT
-
SEA
1 stop8h 05m
Southwest
Sat 7/211:40
SEA
-
ONT
2 stops6h 55m
Southwest
Deal found 11/1£116
Sat 7/306:14
ONT
-
SEA
Nonstop2h 55m
Alaska Airlines
Sat 14/320:56
SEA
-
ONT
Nonstop2h 36m
Alaska Airlines
Deal found 12/1£117
Thu 5/215:30
ONT
-
SEA
Nonstop3h 05m
Delta
Sat 7/220:00
SEA
-
ONT
Nonstop2h 44m
Delta
Deal found 11/1£117
Fri 6/215:30
ONT
-
SEA
Nonstop3h 05m
Delta
Sun 8/211:15
SEA
-
ONT
Nonstop2h 41m
Delta
Deal found 11/1£118
Thu 5/207:30
ONT
-
SEA
Nonstop3h 06m
Delta
Sun 8/211:15
SEA
-
ONT
Nonstop2h 41m
Delta
Deal found 11/1£119
Sat 21/305:15
ONT
-
SEA
1 stop8h 35m
Southwest
Sat 28/306:00
SEA
-
ONT
1 stop12h 45m
Southwest
Deal found 13/1£120
Tue 17/216:02
ONT
-
SEA
Nonstop2h 50m
Alaska Airlines
Mon 23/208:30
SEA
-
ONT
Nonstop2h 38m
Alaska Airlines
Deal found 12/1£124
Tue 17/215:30
ONT
-
SEA
Nonstop3h 03m
Delta
Fri 27/216:40
SEA
-
ONT
1 stop7h 09m
Delta
Deal found 10/1£125
Fri 20/217:00
ONT
-
SEA
1 stop7h 09m
Delta
Sun 22/219:55
SEA
-
ONT
Nonstop2h 42m
Delta
Deal found 11/1£126
Fri 6/206:00
ONT
-
SEA
Nonstop2h 54m
Hawaiian Airlines
Sun 8/208:25
SEA
-
ONT
1 stop4h 41m
Hawaiian Airlines
Deal found 12/1£128
Wed 25/217:02
ONT
-
EDI
2 stops16h 03m
British Airways
Tue 10/310:55
EDI
-
ONT
2 stops18h 12m
British Airways
Deal found 13/1£407

Find flights from Ontario within your budget

 
Find flights departing from Ontario that match your specified budget. Filter results by price range, allowing you to narrow down options and find flights that fit within your financial constraints. Please note that the search results are based on data from user searches, with fares last updated on 13 January 2026. In the last 7 days, Cheapflights users made a total of 858,174 searches

Fly to

Heathrow

Route

Depart

Return

Price

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Sat 7/2

05:50-11:05

1 stop5h 15m

Seattle/Tacoma Intl

Sat 7/2

12:40-20:05

1 stop7h 25m

£112

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Wed 18/2

12:02-14:52

Nonstop2h 50m

Seattle/Tacoma Intl

Wed 25/2

20:05-22:44

Nonstop2h 39m

£117

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Wed 18/3

06:00-08:55

Nonstop2h 55m

Seattle/Tacoma Intl

Tue 24/3

14:30-17:13

Nonstop2h 43m

£117

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Wed 11/2

15:30-18:35

Nonstop3h 05m

Seattle/Tacoma Intl

Thu 19/2

19:55-22:37

Nonstop2h 42m

£124

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Thu 7/5

10:39-13:30

Nonstop2h 51m

Seattle/Tacoma Intl

Tue 12/5

07:05-09:45

Nonstop2h 40m

£124

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Sat 7/3

16:02-18:52

Nonstop2h 50m

Seattle/Tacoma Intl

Mon 9/3

08:30-11:08

Nonstop2h 38m

£124

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Tue 3/2

19:56-14:39

1 stop18h 43m

Seattle/Tacoma Intl

Wed 4/2

18:00-20:36

Nonstop2h 36m

£132

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Tue 17/3

06:00-08:55

Nonstop2h 55m

Seattle/Tacoma Intl

Sat 21/3

05:30-12:23

1 stop6h 53m

£132

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Fri 20/2

06:14-09:09

Nonstop2h 55m

Seattle/Tacoma Intl

Tue 24/2

12:30-15:08

Nonstop2h 38m

£139

OntarioSeattle

ONT - SEA

ONTSEA

Ontario

Tue 3/2

07:30-10:36

Nonstop3h 06m

Seattle/Tacoma Intl

Wed 11/2

05:30-12:16

1 stop6h 46m

£140

Flights are sorted by cheapest return flights first.

Deals found on 12/1

Showing 1-10 of 60 results
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Best time to book a flight from Ontario

Have a flexible travel schedule? Discover the best time to fly from Ontario with our price prediction graph.
Estimated return 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.

Travel insights for flights from Ontario

Get recent, data-driven insights about flights from Ontario including ideal travel times, pricing trends, and more.

When is the best time to book a flight from Ontario?

Use this chart to determine the optimal time to book a return flight from Ontario to Heathrow. Price data was last updated on 9 January 2026.

Booking 62 days in advance of your planned departure date is, on average, the best time to get cheap flights from Ontario. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

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

Currently, December is the cheapest month in which you can book a flight from Ontario (average of £349). Flying from Ontario in June will prove the most costly (average of £520). There are multiple factors that influence the price of a flight so comparing airlines, departure airports and times can help keep costs down.

What are popular destinations to fly to from Ontario?

If you’re flying from Ontario, these routes are more frequently taken by airlines Dallas (99 flights per day), Seattle (96 flights per day) and Phoenix (76 flights per day).

Portland
Portland
From £64
San Francisco
San Francisco
From £633
New York
New York
From £332

What is the cheapest place to fly to from Ontario?

The cheapest city to fly to from Ontario is Portland, with prices starting at £64. Explore other affordable destinations below.

Portland
Portland
From £64
New York
New York
From £332
San Francisco
San Francisco
From £633

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Related info for your journey

Access useful and relevant information related to your journey from Ontario. This can include details such as airport transportation, visa requirements, travel insurance, luggage regulations, and any other information that can ensure a smooth and hassle-free travel experience. Please note that the information is based on general guidance and may need to be verified with official sources. Data last updated 13 January 2026.

  • What are the most popular destinations to fly to from Ontario?

    This month, the top selected destinations from Ontario are Guadalajara, Honolulu, Dallas/Fort Worth Airport. Throughout the year, Dallas/Fort Worth Airport, Denver, Guadalajara are some of the top choices made by users flying from Ontario.

  • What is the cheapest flight from Ontario to anywhere?

    Users have flown out of Ontario for as low as £64 to Portland (prices may vary depending on the airline and departure time). On average, users have booked flights for £350 to fly from Ontario.

  • What is the cheapest month to fly from Ontario?

    At the present moment the cheapest month to fly from Ontario is currently December; with June being the most expensive. Prices will vary depending on multiple factors such as booking in advance, airline and departure airports and times.

  • Where are the cheapest places to fly to from Ontario?

    Check out the cheapest flights from Ontario to embark to:
    Travel from Ontario to Edinburgh from £417 round trip
    Travel from Ontario to London from £434 round trip

  • How does Cheapflights help users find flights from Ontario?

    Deals for flights from Ontario are sourced from 900+ travel sites when you use Cheapflights. When all flight results come back, Cheapflights lets you sort and filter flights using different criteria to choose to your preference, such as price, airport, cabin class, and plenty of other options.

  • Why should you use Cheapflights to find cheap flight tickets from Ontario?

    It’s simple! Cheapflights, which is free to use for everyone, saves millions of users time and money every year by helping them find the cheapest and most suitable flights from Ontario.

  • Can Cheapflights find flights from Ontario with no change fees?

    Yes! Cheapflights helps users easily find flights from Ontario with no change fees.

  • Can Cheapflights notify me if prices for flights from Ontario become cheaper?

    Yes, Cheapflights has a feature called Price Alerts, which offers users the ability to be notified when flight prices change. Track prices for your flight from Ontario today and book when you’re ready!

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Fly with Cheapflights

Find the best flight deals on Cheapflights, where travellers can enjoy low prices and a wide availability of flights to their desired destinations.

How does Cheapflights help users find flights from Ontario?

Deals for flights from Ontario are sourced from 900+ travel sites when you use Cheapflights. When all flight results come back, Cheapflights lets you sort and filter flights using different criteria to choose to your preference, such as price, airport, cabin class, and plenty of other options.

Why should you use Cheapflights to find cheap flight tickets from Ontario?

It’s simple! Cheapflights, which is free to use for everyone, saves millions of users time and money every year by helping them find the cheapest and most suitable flights from Ontario.

Can Cheapflights find flights from Ontario with no change fees?

Yes! Cheapflights helps users easily find flights from Ontario with no change fees.

Can Cheapflights notify me if prices for flights from Ontario become cheaper?

Yes, Cheapflights has a feature called Price Alerts, which offers users the ability to be notified when flight prices change. Track prices for your flight from Ontario today and book when you’re ready!

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