HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Sofia

$550+ Cheap flights from St. Louis (STL) to Sofia (SOF)

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 10/26. Fares are subject to change and may not be available on all flights or dates of travel.
STL — SOF
Oct 11 — Oct 181
Sat 10/11
Sat 10/18
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from St. Louis to Sofia with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheapflights Tip: The best prices from Lambert-St Louis to Sofia are usually found in February or January, booked 36 days in advance, depart on a Saturday or Sunday and return on a Tuesday

Cheap flight deals from St. Louis to Sofia

Discover tips and strategies to find the most affordable flight options for your journey from St. Louis (STL) to Sofia (SOF). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated September 11, 2025.

Round-trip from

$550
(Gotogate)

Popular in

June

Cheapest in

February

Average price

$829
From Lambert-St Louis to Sofia
Search Deals
Highest demand for flights based on searches. 15% potential increase in price ($180 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease ($44 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in September 2025
Search Deals

Find flight deals from St. Louis to Sofia

Cheapest flights from St. Louis to Sofia
Explore the most affordable flight options available from St. Louis to Sofia. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 11, 2025.

This Gotogate deal was found by Cheapflights users on 9/11. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/264:05 pmSTL - SOF
2 stops19h 15mAir Canada
Tue 11/112:15 pmSOF - STL
2 stops33h 14mAir Canada
Deal found 9/11$550
This Gotogate deal was found by Cheapflights users on 9/11. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/264:50 pmSTL - SOF
1 stop18h 10mMultiple Airlines
Tue 11/116:00 amSOF - STL
2 stops41h 29mMultiple Airlines
Deal found 9/11$565
This Cheapflightsfares deal was found by Cheapflights users on 9/10. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/1512:25 pmSTL - SOF
2 stops15h 35mLufthansa
Fri 11/146:10 amSOF - STL
1 stop15h 45mLufthansa
Deal found 9/10$569
This Kiwi.com deal was found by Cheapflights users on 9/11. 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 10/193:30 pmSTL - SOF
1 stop13h 30mLufthansa
Wed 10/296:10 amSOF - STL
1 stop15h 45mLufthansa
Deal found 9/11$576
This Gotogate deal was found by Cheapflights users on 9/11. 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 Gotogate is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/264:50 pmSTL - SOF
1 stop13h 45mLufthansa
Tue 11/112:15 pmSOF - STL
1 stop31h 40mLufthansa
Deal found 9/11$584
This Kiwi.com deal was found by Cheapflights users on 9/11. 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 10/223:30 pmSTL - SOF
1 stop13h 45mLufthansa
Fri 10/316:10 amSOF - STL
1 stop15h 45mLufthansa
Deal found 9/11$591
This Trip.com deal was found by Cheapflights users on 9/11. 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 10/199:15 amSTL - SOF
2 stops18h 45mAir Canada
Wed 10/296:10 amSOF - STL
2 stops40h 19mAir Canada
Deal found 9/11$617
This United deal was found by Cheapflights users on 9/11. 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 is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/1912:25 pmSTL - SOF
2 stops14h 50mMultiple Airlines
Wed 10/296:10 amSOF - STL
1 stop15h 45mMultiple Airlines
Deal found 9/11$619
This United Airlines deal was found by Cheapflights users on 9/11. 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 10/205:28 pmSTL - SOF
2 stops21h 32mUnited Airlines
Thu 10/306:00 amSOF - STL
2 stops35h 51mUnited Airlines
Deal found 9/11$620
This United Airlines deal was found by Cheapflights users on 9/11. 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 10/223:30 pmSTL - SOF
1 stop18h 20mUnited Airlines
Fri 10/312:35 pmSOF - STL
2 stops27h 16mUnited Airlines
Deal found 9/11$624
This Air Canada deal was found by Cheapflights users on 9/11. 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.
Sat 10/184:05 pmSTL - SOF
2 stops35h 10mAir Canada
Fri 10/316:10 amSOF - STL
2 stops40h 19mAir Canada
Deal found 9/11$632

Cheapflights Fare Finder

 
Customize your flight search to find flights from St. Louis 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 September 11, 2025.
Use the filters below to find and compare flights from St. Louis to Sofia that are best for you.

Fly from

St. Louis

Fly to

Sofia

Route

Depart

Return

Price

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Sun 10/26

4:05 pm-6:20 pm

2 stops19h 15m

Sofia

Tue 11/11

2:15 pm-3:29 pm

2 stops33h 14m

$550

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Sun 10/26

4:50 pm-6:00 pm

1 stop18h 10m

Sofia

Tue 11/11

6:00 am-3:29 pm

2 stops41h 29m

$565

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Wed 10/15

12:25 pm-12:00 pm

2 stops15h 35m

Sofia

Fri 11/14

6:10 am-1:55 pm

1 stop15h 45m

$569

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Sun 10/19

12:25 pm-11:15 am

2 stops14h 50m

Sofia

Wed 10/29

6:10 am-2:55 pm

1 stop15h 45m

$619

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Tue 10/21

12:25 pm-11:00 pm

2 stops26h 35m

Sofia

Fri 10/31

2:35 pm-10:51 am

2 stops27h 16m

$620

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Wed 10/22

12:25 pm-12:00 pm

2 stops15h 35m

Sofia

Fri 10/31

2:35 pm-2:25 pm

2 stops30h 50m

$620

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Mon 10/20

3:23 pm-11:00 pm

2 stops23h 37m

Sofia

Wed 10/29

6:10 am-9:54 pm

2 stops22h 44m

$620

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Tue 10/21

12:25 pm-12:00 pm

2 stops15h 35m

Sofia

Thu 10/30

6:00 am-9:54 pm

2 stops22h 54m

$620

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Wed 10/22

3:30 pm-5:50 pm

1 stop18h 20m

Sofia

Thu 10/30

6:00 am-5:39 pm

2 stops18h 39m

$624

St. LouisSofia

STL - SOF

STLSOF

Lambert-St Louis

Sun 10/19

9:20 am-11:15 am

2 stops17h 55m

Sofia

Thu 10/30

6:00 am-9:54 pm

2 stops22h 54m

$624

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/11

Best time to book a flight from St. Louis to Sofia

Have a flexible travel schedule? Discover the best time to fly to Sofia from St. Louis 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 St. Louis to Sofia

How far ahead should I book a flight from St. Louis to Sofia?

Use this chart to determine the optimal time to book a round-trip flight from St. Louis to Sofia. Price data was last updated on August 29, 2025.

The best time to book flights from St. Louis to Sofia is 36 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

What is the cheapest month to book a flight from St. Louis to Sofia?

Currently, November is the cheapest month in which you can book a flight from St. Louis to Sofia (average of $632). Flying from St. Louis to Sofia in June is currently the most expensive (average of $1,185). 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.

Reviews of airlines servicing Sofia

Get insights into the airlines that provide service to Sofia. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Sofia. Reviews last updated September 11, 2025.
Read through reviews of airlines operating flights from St. Louis to Sofia, such as United Airlines and Lufthansa. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
United Airlines
7.4
Good
8,937 reviews

Food

6.6

Boarding

7.7

Overall

7.4

Entertainment

7.1

Crew

8.1

Comfort

7.3

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??
United Airlines
7.4
Good
8,937 reviews
United Airlines
7.4
Good
8,937 reviews

Food

6.6

Boarding

7.7

Overall

7.4

Entertainment

7.1

Crew

8.1

Comfort

7.3

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??
Lufthansa
6.8
Okay
7,409 reviews
United Airlines
7.4
Good
8,937 reviews

Food

6.6

Boarding

7.7

Overall

7.4

Entertainment

7.1

Crew

8.1

Comfort

7.3

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??

Related info for your journey

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

  • How long is the flight from St. Louis to Sofia?

    For as low as $569, Air Canada can have you in Sofia from St. Louis in 15h 35m. Airlines will cover a distance of 5444 mi. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.

  • What are the cheapest airlines flying from St. Louis to Sofia round-trip?

    Lufthansa, at $669, was found to be the cheapest airline from St. Louis to Sofia. An alternate airline flying to your destination would be United Airlines. Users have found that Lufthansa is 31% cheaper than the other options available to this destination.

  • Can I find deals for flights from St. Louis to Sofia that include hotel bookings?

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

  • How can I find direct flights from St. Louis to Sofia?

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

  • Can I find deals for business class flights from St. Louis to Sofia?

    Yes. Cheapflights offers flight deals from St. Louis 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 St. Louis to Sofia?

    Currently, November is the cheapest month in which you can book a flight from St. Louis to Sofia (average of $632). Flying from St. Louis to Sofia in June is currently the most expensive (average of $1,185). 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.

Alternative routes for St. Louis to Sofia

See prices for flight routes from nearby airports that may be better suited for you.
Kansas City to Sofia flights

Top 2 airlines flying from St. Louis to Sofia

Discover the top 2 airlines that operate flights from St. Louis 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 September 11, 2025.
AirlineCheapestAverageFlexibilityOn-time
LufthansaCheapest$669Average$971FlexibilityNo cancel feeOn-time76%
United AirlinesCheapest$711Average$884FlexibilityNo cancel feeOn-time69%

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.