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Sofia

$330+ Cheap flights from Illinois to Sofia (SOF)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 8/19. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — SOF
Jun 4 — Jun 111
Thu 6/4
Thu 6/11
1 adult, Economy
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Cheap flight deals from Illinois to Sofia

Cheapest flights from Illinois to Sofia
Explore the most affordable flight options available from Illinois to Sofia. Find the lowest fares from popular airlines and budget airlines, with prices last updated on May 5, 2026.

This Air France deal was found by Cheapflights users on 5/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air France is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/91:54 pm
STL
-
SOF
2 stops16h 06m
Multiple Airlines
Wed 8/197:00 am
SOF
-
STL
2 stops21h 50m
Multiple Airlines
Deal found 5/1$778
This KAYAK deal was found by Cheapflights users on 4/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/412:55 pm
STL
-
SOF
2 stops21h 45m
Lufthansa
Mon 8/247:00 pm
SOF
-
STL
1 stop26h 25m
Lufthansa
Deal found 4/30$796
This United Airlines deal was found by Cheapflights users on 4/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/44:48 pm
STL
-
SOF
2 stops17h 52m
United Airlines
Mon 8/242:20 pm
SOF
-
STL
2 stops33h 18m
United Airlines
Deal found 4/30$801
This KAYAK deal was found by Cheapflights users on 4/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/86:48 pm
STL
-
SOF
2 stops33h 22m
Lufthansa
Mon 8/247:00 pm
SOF
-
STL
1 stop26h 25m
Lufthansa
Deal found 4/30$807
This KAYAK deal was found by Cheapflights users on 4/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/51:13 pm
STL
-
SOF
2 stops25h 37m
Lufthansa
Mon 8/247:00 pm
SOF
-
STL
1 stop26h 25m
Lufthansa
Deal found 4/30$808
This oojo deal was found by Cheapflights users on 4/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/148:10 pm
ORD
-
SOF
1 stop33h 05m
Turkish Airlines
Sat 9/129:05 pm
SOF
-
ORD
1 stop20h 35m
Turkish Airlines
Deal found 4/30$810
This United Airlines deal was found by Cheapflights users on 4/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/512:10 pm
STL
-
SOF
2 stops14h 30m
United Airlines
Mon 8/242:20 pm
SOF
-
STL
2 stops33h 18m
United Airlines
Deal found 4/30$812
This FlightHub deal was found by Cheapflights users on 4/30. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/711:25 am
ORD
-
SOF
1 stop13h 20m
Turkish Airlines
Wed 9/93:50 pm
SOF
-
ORD
1 stop25h 50m
Turkish Airlines
Deal found 4/30$817
This KAYAK deal was found by Cheapflights users on 5/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/1011:07 am
ORD
-
SOF
2 stops16h 33m
Austrian Airlines
Mon 8/246:55 pm
SOF
-
ORD
1 stop26h 25m
Austrian Airlines
Deal found 5/1$819
This FlightHub deal was found by Cheapflights users on 5/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/208:10 pm
ORD
-
SOF
1 stop34h 50m
Turkish Airlines
Mon 10/59:35 am
SOF
-
ORD
1 stop32h 05m
Turkish Airlines
Deal found 5/3$821
This Kiwi.com deal was found by Cheapflights users on 5/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/97:05 pm
ORD
-
SOF
1 stop11h 50m
Multiple Airlines
Tue 9/18:00 am
SOF
-
ORD
1 stop13h 20m
Multiple Airlines
Deal found 5/1$824
This KAYAK deal was found by Cheapflights users on 5/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/184:20 pm
ORD
-
SOF
1 stop11h 20m
Austrian Airlines
Mon 11/166:45 pm
SOF
-
ORD
2 stops31h 48m
Austrian Airlines
Deal found 5/1$825

Find flight deals from Illinois to Sofia

Keep the following information in mind while searching for Illinois to Sofia flight deals. Data was last updated May 5, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$778
(Air France)

One-way from

$330
(oojo)

Popular in

June

Cheapest in

February

Average price

$976
Provider with most accurate pricing for Chicago (CHI)-Sofia flight deals.
Search Deals
Provider most trusted by Cheapflights users for Chicago (CHI)-Sofia flights.
Search Deals
From Illinois to Sofia
Search Deals
One-way flight from Illinois to Sofia
Search Deals
Highest demand for flights based on searches. 24% potential increase in price ($244 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease ($32 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in May 2026
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Illinois to Sofia that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated May 5, 2026.
Use the filters below to find and compare flights from Illinois to Sofia that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Wed 9/9

4:40 pm-11:15 pm

2 stops22h 35m

Sofia

Wed 9/16

6:20 am-1:25 pm

1 stop15h 05m

$838

ChicagoSofia

MDW - SOF

MDWSOF

Chicago Midway

Tue 8/11

1:05 pm-2:00 pm

2 stops16h 55m

Sofia

Fri 8/28

7:00 am-6:05 pm

2 stops19h 05m

$853

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Sun 8/9

3:30 pm-1:35 pm

1 stop14h 05m

Sofia

Wed 8/19

6:10 am-10:16 pm

2 stops24h 06m

$856

ChicagoSofia

ORD - SOF

ORDSOF

Chicago O'Hare Intl

Tue 9/1

12:57 pm-12:10 pm

2 stops15h 13m

Sofia

Mon 9/14

2:20 pm-12:55 pm

1 stop30h 35m

$862

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Mon 8/31

3:02 pm-11:15 pm

2 stops48h 13m

Sofia

Mon 9/14

2:20 pm-1:25 pm

1 stop31h 05m

$870

ChicagoSofia

MDW - SOF

MDWSOF

Chicago Midway

Tue 8/11

1:05 pm-2:00 pm

2 stops16h 55m

Sofia

Sat 8/29

7:00 am-6:05 pm

2 stops19h 05m

$878

ChicagoSofia

ORD - SOF

ORDSOF

Chicago O'Hare Intl

Fri 8/28

8:31 pm-8:10 pm

2 stops39h 39m

Sofia

Mon 11/9

5:25 pm-5:32 pm

2 stops32h 07m

$880

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Thu 8/6

12:55 pm-12:10 pm

2 stops15h 15m

Sofia

Mon 8/24

6:10 am-12:30 am

2 stops26h 20m

$882

ChicagoSofia

ORD - SOF

ORDSOF

Chicago O'Hare Intl

Mon 7/27

6:00 pm-11:15 pm

1 stop21h 15m

Sofia

Wed 8/12

6:20 am-5:00 pm

2 stops18h 40m

$889

ChicagoSofia

ORD - SOF

ORDSOF

Chicago O'Hare Intl

Sat 8/1

4:48 pm-8:10 pm

2 stops19h 22m

Sofia

Wed 9/30

9:25 pm-7:45 pm

2 stops30h 20m

$896

Flights are sorted by cheapest round-trip flights first.

Deals found on 5/3

Showing 1-10 of 41 resultsSorted by cheapest first
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Best time to book a flight from Illinois to Sofia

Have a flexible travel schedule? Discover the best time to fly to Sofia from Illinois with our price prediction graph.
Estimated round-trip 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.

Cheapflights Insights

Everything you need to know about your flight from Illinois to Sofia

How far ahead should I book a flight from Illinois to Sofia?

Booking 45 days in advance of your planned departure date is, on average, the best time to get cheap flights from Illinois to Sofia. 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 Illinois to Sofia?

Currently, October is the cheapest month in which you can book a flight from Illinois to Sofia (average of $385). Flying from Illinois to Sofia in June is currently the most expensive (average of $1,122). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

How much does it cost to fly round-trip from Illinois to Sofia?

Related info for your journey

Find useful and relevant information for your journey from Illinois to Sofia. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly into for flights to Sofia from Illinois?

    Most people fly into Sofia (SOF) if they book a flight to Sofia from Illinois. Sofia is conveniently located just 4.2 mi from Sofia’s city center.

  • How long is the flight from Illinois to Sofia?

    A quick flight from Illinois to Sofia can take about 15h 40m. United Airlines provides one of the quickest options available for as low as $781. There are 5444 mi between Illinois and Sofia. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the cheapest airlines to fly from Illinois to Sofia one-way?

    The cheapest airlines for a one-way flight from Illinois to Sofia are Turkish Airlines ($295), United Airlines ($305), and Austrian Airlines ($330).

  • What are the most popular routes from Illinois to Sofia?

    While some choose either Chicago Midway - Sofia or Lambert-St Louis - Sofia, Chicago O'Hare Intl - Sofia is the most popular route from Illinois to Sofia.

  • Can I find deals for flights from Illinois to Sofia that include hotel bookings?

    Yes. In addition to deals on Illinois to Sofia flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Illinois to Sofia?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Illinois to Sofia.

  • Can I find deals for business class flights from Illinois to Sofia?

    Yes. Cheapflights offers flight deals from Illinois to Sofia by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Illinois to Sofia?

    Currently, October is the cheapest month in which you can book a flight from Illinois to Sofia (average of $385). Flying from Illinois to Sofia in June is currently the most expensive (average of $1,122). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Top 10 airlines flying from Illinois to Sofia

Discover the top 10 airlines that operate flights from Illinois to Sofia. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated May 5, 2026.
AirlineCheapestAverageFlexibilityOn-time
KLMCheapest$425Average$668FlexibilityNo cancel feeOn-time75%
ITA AirwaysCheapest$508Average$1,157FlexibilityNo cancel feeOn-time81%
Turkish AirlinesCheapest$521Average$700FlexibilityNo cancel feeOn-time77%
United AirlinesCheapest$561Average$834FlexibilityNo cancel feeOn-time69%
SWISSCheapest$564Average$826FlexibilityNo cancel feeOn-time79%
LufthansaCheapest$580Average$866FlexibilityNo cancel feeOn-time76%
LOTCheapest$580Average$874FlexibilityNo cancel feeOn-time81%
Air FranceCheapest$585Average$866FlexibilityNo cancel feeOn-time77%
Austrian AirlinesCheapest$587Average$857FlexibilityNo cancel feeOn-time78%
British AirwaysCheapest$609Average$644FlexibilityNo cancel feeOn-time70%

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