$583 Cheap Flights from Sofia (SOF) to Denver (DEN)

View $583 flight on Tue, Nov 11, 2025Opens in a new window

Popular airlines from Sofia Airport (SOF) to Denver Intl. Airport (DEN)

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Cheap Flights from Sofia to Denver (SOF-DEN)

Prices were available within the past 7 days and start at $583 for one-way flights and $820 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Lufthansa
Thu, Oct 30 - Sun, Apr 26
SOF
Sofia
DEN
Denver
$820 Roundtrip, found 3 days ago
$820
Roundtrip
found 3 days ago
Select Lufthansa flight, departing Thu, Oct 30 from Sofia to Denver, returning Sun, Apr 26, priced at $820 found 3 days ago
Air Canada
Mon, Sep 22 - Mon, Mar 16
SOF
Sofia
DEN
Denver
$822 Roundtrip, found 1 day ago
$822
Roundtrip
found 1 day ago
Select Air Canada flight, departing Mon, Sep 22 from Sofia to Denver, returning Mon, Mar 16, priced at $822 found 1 day ago
Air Canada
Mon, Sep 22 - Mon, Mar 16
SOF
Sofia
DEN
Denver
$828 Roundtrip, found 1 day ago
$828
Roundtrip
found 1 day ago
Select Air Canada flight, departing Mon, Sep 22 from Sofia to Denver, returning Mon, Mar 16, priced at $828 found 1 day ago
Lufthansa
Sat, Nov 1 - Mon, Dec 29
SOF
Sofia
DEN
Denver
$832 Roundtrip, found 6 days ago
$832
Roundtrip
found 6 days ago
Select Lufthansa flight, departing Sat, Nov 1 from Sofia to Denver, returning Mon, Dec 29, priced at $832 found 6 days ago
Lufthansa
Thu, Oct 30 - Sun, Apr 26
SOF
Sofia
DEN
Denver
$833 Roundtrip, found 3 days ago
$833
Roundtrip
found 3 days ago
Select Lufthansa flight, departing Thu, Oct 30 from Sofia to Denver, returning Sun, Apr 26, priced at $833 found 3 days ago
Lufthansa
Mon, Sep 22 - Mon, Mar 16
SOF
Sofia
DEN
Denver
$835 Roundtrip, found 1 day ago
$835
Roundtrip
found 1 day ago
Select Lufthansa flight, departing Mon, Sep 22 from Sofia to Denver, returning Mon, Mar 16, priced at $835 found 1 day ago
Air Canada
Thu, Oct 30 - Sun, Apr 26
SOF
Sofia
DEN
Denver
$835 Roundtrip, found 3 days ago
$835
Roundtrip
found 3 days ago
Select Air Canada flight, departing Thu, Oct 30 from Sofia to Denver, returning Sun, Apr 26, priced at $835 found 3 days ago
United
Fri, Nov 14 - Sun, Nov 30
SOF
Sofia
DEN
Denver
$838 Roundtrip, found 2 days ago
$838
Roundtrip
found 2 days ago
Select United flight, departing Fri, Nov 14 from Sofia to Denver, returning Sun, Nov 30, priced at $838 found 2 days ago
Austrian Airlines
Sat, Nov 1 - Mon, Dec 29
SOF
Sofia
DEN
Denver
$839 Roundtrip, found 6 days ago
$839
Roundtrip
found 6 days ago
Select Austrian Airlines flight, departing Sat, Nov 1 from Sofia to Denver, returning Mon, Dec 29, priced at $839 found 6 days ago
Swiss International Air Lines
Thu, Oct 30 - Sun, Apr 26
SOF
Sofia
DEN
Denver
$841 Roundtrip, found 3 days ago
$841
Roundtrip
found 3 days ago
Select Swiss International Air Lines flight, departing Thu, Oct 30 from Sofia to Denver, returning Sun, Apr 26, priced at $841 found 3 days ago
Flights from Sofia (SOF) to Denver (DEN)
Origin airport
Sofia
Destination airport
Denver Intl.
Airlines serving
Air Canada, Austrian Airlines, British Airways, ITA Airways, Lufthansa, Qatar Airways, Swiss International Air Lines, Turkish Airlines
Roundtrip price
$820
Distance
5875 mi

Sofia to Denver Flights

The cheapest times to fly from Sofia to Denver

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 Denver are during the month of October. You can find some of the cheapest flights from Sofia to Denver with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from Sofia to Denver

Sunday is one of the best days to book for cheap flights from Sofia to Denver: 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 Denver

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 Denver in 2025. You can also book with separate airlines for your outbound and return journeys, from $583 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 Denver 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 Denver 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 Denver Intl. Airport (DEN) cost?
Discover the latest flight deals from SOF to DEN 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 DEN?
The cheapest flights from SOF to DEN 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 DEN?
Use the filter tool on Expedia to compare airlines and find the cheapest carrier that'll take you from SOF to DEN. Sort your results by "Price (lowest to highest)" to snap up a great deal.
How many flights per day from Sofia Airport (SOF) to Denver Intl. Airport (DEN)?
You'll have to catch a flight with a layover if you're traveling from Sofia Airport (SOF) to Denver Intl. Airport (DEN). Direct flights don't operate daily on this route. However, simply filter your search to include one or two stops to find an option that works for you.
What day of the week has the most flights from SOF to DEN?
Friday is usually the busiest day for flights, while Tuesday is often the quietest.* Just remember that flight schedules can change depending on a range of factors, such as the time of year and carrier.*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 Denver Intl. Airport (DEN)?
To arrive at Denver Intl. Airport (DEN) without delays, book a flight that leaves Sofia Airport (SOF) before 3 PM. The likelihood of cancellations is 22% higher, on average, for departures after this time.**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 Denver Intl. Airport (DEN) last-minute?
Holding off until just before your departure to book your flight from SOF to DEN often results in higher prices. While you may find some last-minute deals, they're not always guaranteed. Be flexible with your travel plans to maximize your chances of landing a bargain.
Is it cheaper to book a SOF to DEN flight and hotel package?
Booking a SOF to DEN flight and hotel package is typically cheaper than booking separately. With Expedia, you can enjoy the ease of organizing your travels all in one place. Select from our wide range of stays and then add car rentals, flights and activities to your booking. Bundle everything together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from Sofia Airport (SOF) to Denver Intl. Airport (DEN)?
It's generally possible to reschedule or cancel your SOF to DEN flight. However, for bookings made more than 24 hours ago, additional fees may apply. Refer to your airline's policies in your itinerary to see what changes are allowed and whether any costs are involved. You'll also find more information on our Customer Service portal.

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*Available to One Key members.