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Sofia

$331+ 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 4/14. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — SOF
Dec 10 — Dec 171
Wed 12/10
Wed 12/17
1 adult, Economy
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Find 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 November 10, 2025.

This CrystalTravel deal was found by Cheapflights users on 11/8. 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 CrystalTravel is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/86:42 pmSTL - SOF
2 stops20h 03mLufthansa
Mon 12/151:45 pmSOF - STL
2 stops17h 57mLufthansa
Deal found 11/8$516
This Air France deal was found by Cheapflights users on 11/8. 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.
Sat 12/61:00 pmSTL - SOF
2 stops16h 55mMultiple Airlines
Sat 12/137:00 amSOF - STL
2 stops18h 29mMultiple Airlines
Deal found 11/8$543
This Mytrip deal was found by Cheapflights users on 11/9. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/13:35 pmORD - SOF
2 stops23h 55mMultiple Airlines
Mon 12/152:35 pmSOF - ORD
2 stops33h 45mMultiple Airlines
Deal found 11/9$563
This Kiwi.com deal was found by Cheapflights users on 11/9. 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.
Wed 11/129:50 pmORD - SOF
1 stop12h 30mLufthansa
Wed 11/192:25 pmSOF - ORD
1 stop13h 40mLufthansa
Deal found 11/9$565
This Mytrip deal was found by Cheapflights users on 11/10. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/87:05 amORD - SOF
2 stops32h 25mMultiple Airlines
Mon 12/152:35 pmSOF - ORD
2 stops33h 45mMultiple Airlines
Deal found 11/10$566
This Mytrip deal was found by Cheapflights users on 11/8. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/610:47 amSTL - SOF
2 stops18h 13mBritish Airways
Sat 12/1312:05 pmSOF - STL
2 stops43h 33mBritish Airways
Deal found 11/8$568
This Kiwi.com deal was found by Cheapflights users on 11/10. 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.
Mon 11/179:50 pmORD - SOF
1 stop12h 30mLufthansa
Mon 12/156:05 amSOF - ORD
2 stops15h 05mLufthansa
Deal found 11/10$573
This CrystalTravel deal was found by Cheapflights users on 11/8. 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 CrystalTravel is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/279:50 pmORD - SOF
1 stop16h 55mLufthansa
Thu 12/112:35 pmSOF - ORD
1 stop13h 30mLufthansa
Deal found 11/8$574
This CrystalTravel deal was found by Cheapflights users on 11/8. 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 CrystalTravel is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/129:50 pmORD - SOF
1 stop12h 30mLufthansa
Wed 4/82:00 pmSOF - ORD
1 stop13h 55mLufthansa
Deal found 11/8$575
This Kiwi.com deal was found by Cheapflights users on 11/10. 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.
Mon 12/89:50 pmORD - SOF
1 stop12h 30mLufthansa
Tue 12/237:05 pmSOF - ORD
1 stop31h 20mLufthansa
Deal found 11/10$576
This Kiwi.com deal was found by Cheapflights users on 11/8. 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 11/3010:35 pmORD - SOF
1 stop16h 10mLufthansa
Sun 12/142:25 pmSOF - ORD
1 stop13h 40mLufthansa
Deal found 11/8$577
This Kiwi.com deal was found by Cheapflights users on 11/9. 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.
Fri 11/286:50 pmORD - SOF
1 stop31h 25mMultiple Airlines
Fri 12/122:35 pmSOF - ORD
1 stop13h 30mMultiple Airlines
Deal found 11/9$579

Cheap flight deals from Illinois to Sofia

Keep the following information in mind while searching for Illinois to Sofia flight deals. Data was last updated November 10, 2025.

Most accurate provider

Gotogate
3 stars

Most trusted provider

Gotogate
3 stars

Round-trip from

$516
(CrystalTravel)

One-way from

$331
(Kiwi.com)

Popular in

June

Cheapest in

February

Average price

$641
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. 25% potential increase in price ($254 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 5% potential price decrease ($38 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in November 2025
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 November 10, 2025.
Use the filters below to find and compare flights from Illinois to Sofia that are best for you.

Fly from

Illinois

Fly to

Sofia

Route

Depart

Return

Price

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Mon 12/8

6:42 pm-10:45 pm

2 stops20h 03m

Sofia

Mon 12/15

1:45 pm-11:42 pm

2 stops17h 57m

$516

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Wed 1/7

9:57 am-10:45 pm

2 stops28h 48m

Sofia

Sat 1/17

2:25 pm-3:29 pm

2 stops33h 04m

$539

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Wed 1/7

9:57 am-10:45 pm

2 stops28h 48m

Sofia

Tue 1/13

6:00 am-3:29 pm

2 stops41h 29m

$539

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Fri 1/9

11:20 am-6:20 pm

2 stops23h 00m

Sofia

Thu 1/15

2:35 pm-3:29 pm

2 stops32h 54m

$539

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Fri 1/9

6:40 pm-6:20 pm

2 stops15h 40m

Sofia

Tue 1/13

6:00 am-3:29 pm

2 stops41h 29m

$539

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Thu 1/8

8:30 am-10:45 pm

2 stops30h 15m

Sofia

Sat 1/17

2:25 pm-3:29 pm

2 stops33h 04m

$539

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Wed 1/7

8:30 am-6:20 pm

2 stops25h 50m

Sofia

Thu 1/15

2:35 pm-3:29 pm

2 stops32h 54m

$539

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Fri 1/23

3:50 pm-1:35 pm

1 stop13h 45m

Sofia

Sun 2/1

6:10 am-11:59 pm

2 stops25h 49m

$542

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Thu 1/8

8:45 am-10:45 pm

2 stops30h 00m

Sofia

Fri 1/16

6:10 am-10:58 pm

2 stops24h 48m

$543

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Wed 1/7

8:30 am-10:45 pm

2 stops30h 15m

Sofia

Fri 1/16

6:10 am-10:58 pm

2 stops24h 48m

$543

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/10

Showing 1-10 of 43 results
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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

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

Currently, November is the cheapest month in which you can book a flight from Illinois to Sofia (average of $491). Flying from Illinois to Sofia in June is currently the most expensive (average of $826). 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.

What is the cheapest time of day to fly from IL to SOF?

Find hourly flight availability from Illinois to Sofia. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated November 10, 2025.

A simple way to save on the total cost of your ticket is to fly from Illinois to Sofia in the evening. If you’re flexible enough to do this you can expect to save up to 35% on your trip compared to booking a flight in the morning.

What is the cheapest day to fly from Illinois to Sofia?

Use this chart to determine the cheapest time to fly round-trip from Illinois to Sofia. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Illinois to Sofia flight should consider departing on Tuesday mornings when fares are most often at their lowest. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.

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 20h 03m. Lufthansa provides one of the quickest options available for as low as $516. 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 Air Serbia ($359), United Airlines ($458), and Air France ($536).

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

    While some choose either Lambert-St Louis - Sofia or Chicago Midway - 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, November is the cheapest month in which you can book a flight from Illinois to Sofia (average of $491). Flying from Illinois to Sofia in June is currently the most expensive (average of $826). 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

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Alternative routes for Illinois to Sofia

See prices for flight routes from nearby airports that may be better suited for you.
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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 November 10, 2025.
AirlineCheapestAverageFlexibilityOn-time
Turkish AirlinesCheapest$511Average$770FlexibilityNo cancel feeOn-time77%
KLMCheapest$533Average$696FlexibilityNo cancel feeOn-time75%
LOTCheapest$570Average$967FlexibilityNo cancel feeOn-time81%
Air FranceCheapest$585Average$624FlexibilityNo cancel feeOn-time77%
LufthansaCheapest$590Average$883FlexibilityNo cancel feeOn-time76%
SWISSCheapest$593Average$808FlexibilityNo cancel feeOn-time79%
United AirlinesCheapest$600Average$791FlexibilityNo cancel feeOn-time69%
Austrian AirlinesCheapest$606Average$976FlexibilityNo cancel feeOn-time78%
British AirwaysCheapest$611Average$759FlexibilityNo cancel feeOn-time70%
Air SerbiaCheapest$634Average$1,010FlexibilityNo cancel feeOn-timeN/A

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