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Sofia

$267+ 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 1/8. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — SOF
Jan 3 — Jan 101
Sat 1/3
Sat 1/10
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 December 4, 2025.

This United Airlines deal was found by Cheapflights users on 12/1. 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 12/296:10 pmORD - SOF
2 stops20h 35mUnited Airlines
Tue 1/132:00 pmSOF - ORD
1 stop32h 10mUnited Airlines
Deal found 12/1$555
This United Airlines deal was found by Cheapflights users on 12/1. 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 12/89:50 pmORD - SOF
1 stop12h 30mUnited Airlines
Sun 2/156:10 amSOF - ORD
1 stop17h 10mUnited Airlines
Deal found 12/1$557
This KAYAK deal was found by Cheapflights users on 12/1. 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 12/296:10 pmORD - SOF
2 stops20h 35mLufthansa
Mon 1/127:05 pmSOF - ORD
1 stop27h 05mLufthansa
Deal found 12/1$560
This KAYAK deal was found by Cheapflights users on 12/1. 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 12/84:20 pmORD - SOF
1 stop17h 40mAustrian Airlines
Sun 2/156:45 pmSOF - ORD
2 stops50h 00mAustrian Airlines
Deal found 12/1$561
This KAYAK deal was found by Cheapflights users on 12/1. 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 12/81:05 pmORD - SOF
2 stops26h 50mAustrian Airlines
Thu 2/197:55 amSOF - ORD
2 stops18h 46mAustrian Airlines
Deal found 12/1$562
This KAYAK deal was found by Cheapflights users on 12/1. 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.
Wed 12/316:00 pmORD - SOF
1 stop11h 15mLufthansa
Sat 1/176:25 amSOF - ORD
1 stop16h 55mLufthansa
Deal found 12/1$564
This KAYAK deal was found by Cheapflights users on 12/1. 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 12/81:05 pmORD - SOF
2 stops20h 55mAustrian Airlines
Tue 2/177:55 amSOF - ORD
2 stops36h 15mAustrian Airlines
Deal found 12/1$565
This KAYAK deal was found by Cheapflights users on 12/1. 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 12/81:05 pmORD - SOF
2 stops14h 45mAustrian Airlines
Mon 2/1612:35 pmSOF - ORD
2 stops32h 10mAustrian Airlines
Deal found 12/1$566
This KLM deal was found by Cheapflights users on 12/1. 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.
Wed 12/101:23 pmORD - SOF
2 stops16h 42mKLM
Wed 2/187:00 amSOF - ORD
1 stop15h 20mKLM
Deal found 12/1$569
This SWISS deal was found by Cheapflights users on 12/1. 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 SWISS is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/296:05 pmORD - SOF
3 stops61h 10mSWISS
Tue 1/132:00 pmSOF - ORD
2 stops34h 20mSWISS
Deal found 12/1$570
This KAYAK deal was found by Cheapflights users on 12/1. 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.
Tue 12/96:45 pmORD - SOF
2 stops20h 00mLufthansa
Wed 2/186:05 amSOF - ORD
2 stops15h 20mLufthansa
Deal found 12/1$571
This Air France deal was found by Cheapflights users on 12/1. 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.
Wed 12/101:50 pmMDW - SOF
2 stops16h 15mMultiple Airlines
Tue 2/177:00 amSOF - MDW
2 stops18h 45mMultiple Airlines
Deal found 12/1$573

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 December 4, 2025.

Most accurate provider

Justfly.com
3 stars

Most trusted provider

Justfly.com
3 stars

Round-trip from

$528
(United Airlines)

One-way from

$267
(Kiwi.com)

Popular in

June

Cheapest in

February

Average price

$782
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 ($259 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 December 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 December 4, 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

Wed 1/28

3:11 pm-10:45 pm

2 stops23h 34m

Sofia

Sun 2/1

6:10 am-9:13 pm

2 stops23h 03m

$528

ChicagoSofia

ORD - SOF

ORDSOF

Chicago O'Hare Intl

Mon 12/29

6:10 pm-10:45 pm

2 stops20h 35m

Sofia

Tue 1/13

2:00 pm-2:10 pm

1 stop32h 10m

$555

ChicagoSofia

ORD - SOF

ORDSOF

Chicago O'Hare Intl

Sun 4/19

9:40 pm-11:10 pm

1 stop17h 30m

Sofia

Sat 5/2

2:00 pm-7:55 pm

1 stop13h 55m

$560

ChicagoSofia

ORD - SOF

ORDSOF

Chicago O'Hare Intl

Thu 4/2

9:40 pm-6:40 pm

1 stop13h 00m

Sofia

Tue 4/21

12:50 pm-6:15 pm

1 stop13h 25m

$562

ChicagoSofia

ORD - SOF

ORDSOF

Chicago O'Hare Intl

Sun 1/25

9:50 pm-6:20 pm

1 stop12h 30m

Sofia

Sun 2/8

6:05 am-6:25 pm

1 stop20h 20m

$562

ChicagoSofia

ORD - SOF

ORDSOF

Chicago O'Hare Intl

Tue 3/31

9:40 pm-6:40 pm

1 stop13h 00m

Sofia

Sat 4/18

6:10 am-2:00 pm

1 stop15h 50m

$562

ChicagoSofia

ORD - SOF

ORDSOF

Chicago O'Hare Intl

Fri 1/23

2:18 pm-1:15 pm

2 stops14h 57m

Sofia

Fri 1/30

6:10 am-6:51 pm

2 stops20h 41m

$567

ChicagoSofia

ORD - SOF

ORDSOF

Chicago O'Hare Intl

Tue 4/21

3:00 pm-1:15 pm

1 stop14h 15m

Sofia

Sun 5/3

1:55 pm-7:55 pm

1 stop14h 00m

$571

ChicagoSofia

ORD - SOF

ORDSOF

Chicago O'Hare Intl

Tue 4/21

6:15 pm-6:00 pm

1 stop15h 45m

Sofia

Sat 5/2

6:10 am-12:55 pm

1 stop14h 45m

$571

ChicagoSofia

ORD - SOF

ORDSOF

Chicago O'Hare Intl

Thu 1/29

9:50 pm-10:45 pm

1 stop16h 55m

Sofia

Mon 2/2

1:45 pm-2:10 pm

1 stop32h 25m

$572

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/2

Showing 1-10 of 45 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 $492). 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 December 4, 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.

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 17h. United Airlines provides one of the quickest options available for as low as $576. There are 5198 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, November is the cheapest month in which you can book a flight from Illinois to Sofia (average of $492). 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 December 4, 2025.
AirlineCheapestAverageFlexibilityOn-time
Turkish AirlinesCheapest$509Average$761FlexibilityNo cancel feeOn-time77%
KLMCheapest$569Average$677FlexibilityNo cancel feeOn-time75%
LOTCheapest$574Average$968FlexibilityNo cancel feeOn-time81%
Air FranceCheapest$585Average$624FlexibilityNo cancel feeOn-time77%
LufthansaCheapest$588Average$877FlexibilityNo cancel feeOn-time76%
SWISSCheapest$593Average$808FlexibilityNo cancel feeOn-time79%
United AirlinesCheapest$599Average$788FlexibilityNo cancel feeOn-time69%
British AirwaysCheapest$611Average$759FlexibilityNo cancel feeOn-time70%
Austrian AirlinesCheapest$613Average$974FlexibilityNo cancel feeOn-time78%
Air SerbiaCheapest$634Average$1,001FlexibilityNo cancel feeOn-timeN/A

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