$640 Cheap Flights from Sofia (SOF) to Ontario (ONT)

View $640 flight on Mon, Oct 13, 2025Opens in a new window

Popular airlines from Sofia Airport (SOF) to Los Angeles - Ontario Intl. Airport (ONT)

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Cheap Flights from Sofia to Ontario (SOF-ONT)

Prices were available within the past 7 days and start at $640 for one-way flights and $928 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

United
Thu, Aug 21 - Tue, Sep 2
SOF
Sofia
ONT
Ontario
$928 Roundtrip, found 13 hours ago
$928
Roundtrip
found 13 hours ago
Select United flight, departing Thu, Aug 21 from Sofia to Ontario, returning Tue, Sep 2, priced at $928 found 13 hours ago
Lufthansa
Thu, Aug 21 - Tue, Sep 2
SOF
Sofia
ONT
Ontario
$931 Roundtrip, found 13 hours ago
$931
Roundtrip
found 13 hours ago
Select Lufthansa flight, departing Thu, Aug 21 from Sofia to Ontario, returning Tue, Sep 2, priced at $931 found 13 hours ago
United
Thu, Aug 21 - Tue, Sep 2
SOF
Sofia
ONT
Ontario
$935 Roundtrip, found 13 hours ago
$935
Roundtrip
found 13 hours ago
Select United flight, departing Thu, Aug 21 from Sofia to Ontario, returning Tue, Sep 2, priced at $935 found 13 hours ago
British Airways
Wed, Dec 10 - Fri, Jan 2
SOF
Sofia
ONT
Ontario
$939 Roundtrip, found 3 hours ago
$939
Roundtrip
found 3 hours ago
Select British Airways flight, departing Wed, Dec 10 from Sofia to Ontario, returning Fri, Jan 2, priced at $939 found 3 hours ago
Lufthansa
Thu, Aug 21 - Tue, Sep 2
SOF
Sofia
ONT
Ontario
$940 Roundtrip, found 13 hours ago
$940
Roundtrip
found 13 hours ago
Select Lufthansa flight, departing Thu, Aug 21 from Sofia to Ontario, returning Tue, Sep 2, priced at $940 found 13 hours ago
Lufthansa
Thu, Aug 21 - Tue, Sep 2
SOF
Sofia
ONT
Ontario
$944 Roundtrip, found 13 hours ago
$944
Roundtrip
found 13 hours ago
Select Lufthansa flight, departing Thu, Aug 21 from Sofia to Ontario, returning Tue, Sep 2, priced at $944 found 13 hours ago
United
Thu, Aug 21 - Sat, Aug 30
SOF
Sofia
ONT
Ontario
$947 Roundtrip, found 1 day ago
$947
Roundtrip
found 1 day ago
Select United flight, departing Thu, Aug 21 from Sofia to Ontario, returning Sat, Aug 30, priced at $947 found 1 day ago
Lufthansa
Thu, Aug 21 - Tue, Sep 2
SOF
Sofia
ONT
Ontario
$955 Roundtrip, found 13 hours ago
$955
Roundtrip
found 13 hours ago
Select Lufthansa flight, departing Thu, Aug 21 from Sofia to Ontario, returning Tue, Sep 2, priced at $955 found 13 hours ago
Swiss International Air Lines
Thu, Aug 21 - Tue, Sep 2
SOF
Sofia
ONT
Ontario
$956 Roundtrip, found 13 hours ago
$956
Roundtrip
found 13 hours ago
Select Swiss International Air Lines flight, departing Thu, Aug 21 from Sofia to Ontario, returning Tue, Sep 2, priced at $956 found 13 hours ago
Air France
Tue, Dec 9 - Mon, Dec 22
SOF
Sofia
ONT
Ontario
$1,218 Roundtrip, found 3 hours ago
$1,218
Roundtrip
found 3 hours ago
Select Air France flight, departing Tue, Dec 9 from Sofia to Ontario, returning Mon, Dec 22, priced at $1,218 found 3 hours ago
Flights from Sofia (SOF) to Ontario (ONT)
Origin airport
Sofia
Destination airport
Los Angeles - Ontario Intl.
Airlines serving
Qatar Airways, United
Roundtrip price
$928
Distance
6588 mi

Sofia to Ontario Flights

The cheapest times to fly from Sofia to Ontario

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from Sofia to Ontario are during the month of August. You can find some of the cheapest flights from Sofia to Ontario with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Sofia to Ontario

Sunday is one of the best days to book for cheap flights from Sofia to Ontario: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from Sofia to Ontario

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from Sofia to Ontario in 2025. You can also book with separate airlines for your outbound and return journeys, from $640 one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap Sofia to Ontario flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your Sofia to Ontario airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

Frequently asked questions

How much does a flight from Sofia Airport (SOF) to Los Angeles - Ontario Intl. Airport (ONT) cost?
Discover the latest flight deals from SOF to ONT by entering your preferred travel dates and searching on Expedia. Easily compare prices by departure date if you have flexibility with your schedule and use handy filters to explore prices for your preferred journey. As a member of One Key™, our free loyalty program, you can use Price Tracking to watch fares and receive notifications if prices go up or down.
What is the cheapest month to fly from SOF to ONT?
The cheapest flights from SOF to ONT are usually during off-peak season, when demand is lower. To save money, avoid flying during public holidays, school breaks and major local events.
What is the cheapest airline that flies from SOF to ONT?
Use the filter tool on Expedia to compare airlines and find the cheapest carrier that'll take you from SOF to ONT. Sort your results by "Price (lowest to highest)" to snap up a great deal.
How many flights per day from Sofia Airport (SOF) to Los Angeles - Ontario Intl. Airport (ONT)?
Nonstop flights from Sofia Airport (SOF) to Los Angeles - Ontario Intl. Airport (ONT) aren't available daily, so you'll need to take a flight with a layover. Explore your options with our filter tool. Enter your dates and choose either "1 Stop" or "2+ Stops."
What day of the week has the most flights from SOF to ONT?
Generally you'll find the widest variety of flight choices on a Friday. Tuesdays tend to be the quietest.* However, this can change depending on the airline, season and other factors.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from Sofia Airport (SOF) to Los Angeles - Ontario Intl. Airport (ONT)?
To reach Los Angeles - Ontario Intl. Airport (ONT) on time, opt for a flight that leaves Sofia Airport (SOF) before 3 PM. The likelihood of cancellations is 22% higher, on average, for departures after this hour.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
Is it cheaper to buy a plane ticket from Sofia Airport (SOF) to Los Angeles - Ontario Intl. Airport (ONT) last-minute?
Holding off until right before your break to book a ticket from SOF to ONT often results in higher prices. While it's possible to find some last-minute deals, they're not always guaranteed. Be flexible with your itinerary to maximize your chances of snagging a bargain.
Is it cheaper to book a SOF to ONT flight and hotel package?
Securing a SOF to ONT flight and hotel package is usually cheaper than booking separately. With Expedia, you can enjoy the ease of organizing your trip in one place. Select from our extensive range of accommodations and then add activities, car rentals and flights to your booking. Bundle it all together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Sofia Airport (SOF) to Los Angeles - Ontario Intl. Airport (ONT)?
If you booked your SOF to ONT flight within the last 24 hours, you may be able to modify or cancel it without any fees. Depending on the airline and the ticket type you purchased, additional charges may apply for changes beyond this timeframe. Airline policies and contact information can be found in your itinerary or confirmation email. Or, visit our Customer Service portal if you'd like more information.

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*Available to One Key members.