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Sofia

$250+ 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 3/2. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — SOF
Feb 1 — Feb 81
Sun 2/1
Sun 2/8
1 adult, Economy
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Cheap flight deals from Illinois to Sofia

Best flights from Illinois to Sofia
Discover carefully curated flight deals from Illinois to Sofia that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated January 2, 2026.

This United Airlines deal was found by Cheapflights users on 12/30. 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.
Thu 1/298:30 amSTL - SOF
2 stops21h 20mUnited Airlines
Mon 2/26:10 amSOF - STL
2 stops24h 48mUnited Airlines
Deal found 12/30$558
This FlightHub deal was found by Cheapflights users on 12/31. 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.
Wed 4/87:50 pmORD - SOF
1 stop28h 55mTurkish Airlines
Sun 4/123:50 pmSOF - ORD
1 stop34h 25mTurkish Airlines
Deal found 12/31$575
This oojo deal was found by Cheapflights users on 12/31. 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.
Sat 2/149:55 pmORD - SOF
1 stop11h 55mLOT
Sat 2/212:35 pmSOF - ORD
1 stop13h 25mLOT
Deal found 12/31$578
This Cheapflightsfares deal was found by Cheapflights users on 12/31. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/81:00 pmORD - SOF
2 stops14h 40mMultiple Airlines
Sun 4/1212:55 pmSOF - ORD
1 stop13h 20mMultiple Airlines
Deal found 12/31$615
This KLM deal was found by Cheapflights users on 1/1. 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 KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/181:10 pmMDW - SOF
2 stops16h 50mKLM
Thu 4/307:00 amSOF - MDW
2 stops18h 54mKLM
Deal found 1/1$629
This oojo deal was found by Cheapflights users on 12/31. 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.
Sun 2/19:55 pmORD - SOF
2 stops31h 55mLOT
Sun 3/226:35 pmSOF - ORD
2 stops33h 20mLOT
Deal found 12/31$601
This FlightHub deal was found by Cheapflights users on 12/31. 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.
Tue 5/1211:25 amORD - SOF
1 stop24h 50mTurkish Airlines
Fri 5/299:35 amSOF - ORD
1 stop16h 40mTurkish Airlines
Deal found 12/31$606
This United Airlines deal was found by Cheapflights users on 12/30. 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.
Thu 3/59:50 pmORD - SOF
1 stop16h 55mUnited Airlines
Mon 3/96:10 amSOF - ORD
1 stop15h 15mUnited Airlines
Deal found 12/30$611
This Air France deal was found by Cheapflights users on 12/31. 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.
Fri 1/301:49 pmMDW - SOF
2 stops16h 06mMultiple Airlines
Wed 2/187:00 amSOF - MDW
2 stops18h 45mMultiple Airlines
Deal found 12/31$624
This KLM deal was found by Cheapflights users on 1/1. 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 KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 4/191:10 pmMDW - SOF
2 stops16h 50mKLM
Thu 4/307:00 amSOF - MDW
2 stops18h 54mKLM
Deal found 1/1$629
This United Airlines deal was found by Cheapflights users on 1/1. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/179:40 pmORD - SOF
1 stop17h 30mUnited Airlines
Mon 4/276:20 amSOF - ORD
1 stop14h 35mUnited Airlines
Deal found 1/1$612
This Air France deal was found by Cheapflights users on 12/31. 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.
Fri 1/301:49 pmMDW - SOF
2 stops16h 06mMultiple Airlines
Fri 2/67:00 amSOF - MDW
2 stops18h 29mMultiple Airlines
Deal found 12/31$624
This KLM deal was found by Cheapflights users on 1/1. 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 KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/181:10 pmMDW - SOF
2 stops16h 50mKLM
Wed 4/297:00 amSOF - MDW
2 stops17h 36mKLM
Deal found 1/1$629
This United Airlines deal was found by Cheapflights users on 1/1. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/215:55 pmORD - SOF
1 stop21h 15mUnited Airlines
Sat 5/26:20 amSOF - ORD
1 stop21h 35mUnited Airlines
Deal found 1/1$612
This Air France deal was found by Cheapflights users on 1/1. 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 2/11:51 pmMDW - SOF
2 stops16h 04mMultiple Airlines
Sat 2/287:00 amSOF - MDW
2 stops17h 14mMultiple Airlines
Deal found 1/1$625
This Trip.com deal was found by Cheapflights users on 12/31. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 3/154:50 pmSTL - SOF
1 stop22h 55mLufthansa
Sat 3/212:25 pmSOF - STL
1 stop31h 30mLufthansa
Deal found 12/31$1,553
This United Airlines deal was found by Cheapflights users on 1/1. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/179:40 pmORD - SOF
1 stop13h 00mUnited Airlines
Tue 4/286:10 amSOF - ORD
1 stop14h 45mUnited Airlines
Deal found 1/1$612
This Air France deal was found by Cheapflights users on 1/1. 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 2/11:51 pmMDW - SOF
2 stops16h 04mMultiple Airlines
Sun 3/17:00 amSOF - MDW
2 stops18h 45mMultiple Airlines
Deal found 1/1$625
This United Airlines deal was found by Cheapflights users on 1/1. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/209:40 pmORD - SOF
1 stop13h 00mUnited Airlines
Mon 4/272:20 pmSOF - ORD
1 stop13h 35mUnited Airlines
Deal found 1/1$612
This Air France deal was found by Cheapflights users on 1/1. 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.
Fri 1/301:49 pmMDW - SOF
2 stops16h 06mMultiple Airlines
Mon 3/27:00 amSOF - MDW
2 stops18h 45mMultiple Airlines
Deal found 1/1$625
This United Airlines deal was found by Cheapflights users on 1/1. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/169:40 pmORD - SOF
1 stop17h 30mUnited Airlines
Sun 5/312:55 pmSOF - ORD
1 stop13h 20mUnited Airlines
Deal found 1/1$614
This Air France deal was found by Cheapflights users on 1/1. 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 2/11:51 pmMDW - SOF
2 stops16h 04mMultiple Airlines
Mon 3/27:00 amSOF - MDW
2 stops18h 45mMultiple Airlines
Deal found 1/1$625
This Air Canada deal was found by Cheapflights users on 12/31. 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 Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 3/154:05 pmSTL - SOF
2 stops19h 15mAir Canada
Sat 3/216:25 amSOF - STL
3 stops21h 40mAir Canada
Deal found 12/31$2,129
This United Airlines deal was found by Cheapflights users on 1/1. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/209:40 pmORD - SOF
1 stop17h 30mUnited Airlines
Sun 5/312:55 pmSOF - ORD
1 stop13h 20mUnited Airlines
Deal found 1/1$614
This Air France deal was found by Cheapflights users on 1/2. 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.
Mon 1/191:49 pmMDW - SOF
2 stops16h 16mMultiple Airlines
Tue 2/37:00 amSOF - MDW
2 stops18h 29mMultiple Airlines
Deal found 1/2$625
This Air France deal was found by Cheapflights users on 1/1. 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.
Fri 1/301:49 pmMDW - SOF
2 stops16h 06mMultiple Airlines
Sat 2/287:00 amSOF - MDW
2 stops17h 14mMultiple Airlines
Deal found 1/1$625
This United Airlines deal was found by Cheapflights users on 12/30. 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.
Fri 5/13:30 pmSTL - SOF
1 stop13h 35mUnited Airlines
Fri 5/156:20 amSOF - STL
1 stop15h 05mUnited Airlines
Deal found 12/30$696
This Mytrip deal was found by Cheapflights users on 12/30. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/17:30 amSTL - SOF
2 stops20h 40mMultiple Airlines
Fri 5/156:20 amSOF - STL
1 stop15h 05mMultiple Airlines
Deal found 12/30$696
This United Airlines deal was found by Cheapflights users on 12/31. 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.
Sun 3/154:05 pmSTL - SOF
2 stops18h 55mUnited Airlines
Sat 3/212:25 pmSOF - STL
2 stops37h 42mUnited Airlines
Deal found 12/31$917

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 January 2, 2026.

Most accurate provider

Justfly.com
3 stars

Most trusted provider

Justfly.com
3 stars

Round-trip from

$550
(oojo)

One-way from

$250
(Kiwi.com)

Popular in

June

Cheapest in

February

Average price

$665
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. 26% potential increase in price ($263 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 January 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 January 2, 2026.
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

Thu 1/29

8:30 am-1:50 pm

2 stops21h 20m

Sofia

Mon 2/2

6:10 am-10:58 pm

2 stops24h 48m

$558

ChicagoSofia

ORD - SOF

ORDSOF

Chicago O'Hare Intl

Wed 4/8

7:50 pm-8:45 am

1 stop28h 55m

Sofia

Sun 4/12

3:50 pm-6:15 pm

1 stop34h 25m

$575

ChicagoSofia

ORD - SOF

ORDSOF

Chicago O'Hare Intl

Sat 2/14

9:55 pm-5:50 pm

1 stop11h 55m

Sofia

Sat 2/21

2:35 pm-8:00 pm

1 stop13h 25m

$578

ChicagoSofia

ORD - SOF

ORDSOF

Chicago O'Hare Intl

Sun 2/1

9:55 pm-1:50 pm

2 stops31h 55m

Sofia

Sun 3/22

6:35 pm-8:55 pm

2 stops33h 20m

$601

ChicagoSofia

ORD - SOF

ORDSOF

Chicago O'Hare Intl

Tue 5/12

11:25 am-8:15 pm

1 stop24h 50m

Sofia

Fri 5/29

9:35 am-6:15 pm

1 stop16h 40m

$606

ChicagoSofia

ORD - SOF

ORDSOF

Chicago O'Hare Intl

Thu 3/5

9:50 pm-10:45 pm

1 stop16h 55m

Sofia

Mon 3/9

6:10 am-2:25 pm

1 stop15h 15m

$611

ChicagoSofia

ORD - SOF

ORDSOF

Chicago O'Hare Intl

Fri 4/17

9:40 pm-11:10 pm

1 stop17h 30m

Sofia

Mon 4/27

6:20 am-12:55 pm

1 stop14h 35m

$612

ChicagoSofia

ORD - SOF

ORDSOF

Chicago O'Hare Intl

Tue 4/21

5:55 pm-11:10 pm

1 stop21h 15m

Sofia

Sat 5/2

6:20 am-7:55 pm

1 stop21h 35m

$612

ChicagoSofia

ORD - SOF

ORDSOF

Chicago O'Hare Intl

Fri 4/17

9:40 pm-6:40 pm

1 stop13h 00m

Sofia

Tue 4/28

6:10 am-12:55 pm

1 stop14h 45m

$612

ChicagoSofia

ORD - SOF

ORDSOF

Chicago O'Hare Intl

Mon 4/20

9:40 pm-6:40 pm

1 stop13h 00m

Sofia

Mon 4/27

2:20 pm-7:55 pm

1 stop13h 35m

$612

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/30

Showing 1-10 of 38 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 $473). Flying from Illinois to Sofia in June is currently the most expensive (average of $825). 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.

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 11h 55m. United Airlines provides one of the quickest options available for as low as $578. There are 5194 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 Air Serbia ($327).

  • 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, November is the cheapest month in which you can book a flight from Illinois to Sofia (average of $473). Flying from Illinois to Sofia in June is currently the most expensive (average of $825). 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 January 2, 2026.
AirlineCheapestAverageFlexibilityOn-time
Turkish AirlinesCheapest$517Average$767FlexibilityNo cancel feeOn-time77%
KLMCheapest$569Average$675FlexibilityNo cancel feeOn-time75%
United AirlinesCheapest$582Average$789FlexibilityNo cancel feeOn-time69%
Air FranceCheapest$585Average$624FlexibilityNo cancel feeOn-time77%
LOTCheapest$587Average$972FlexibilityNo cancel feeOn-time81%
LufthansaCheapest$588Average$878FlexibilityNo cancel feeOn-time76%
SWISSCheapest$593Average$812FlexibilityNo cancel feeOn-time79%
Austrian AirlinesCheapest$606Average$973FlexibilityNo cancel feeOn-time78%
British AirwaysCheapest$611Average$759FlexibilityNo cancel feeOn-time70%
Air SerbiaCheapest$631Average$988FlexibilityNo cancel feeOn-timeN/A

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