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$309+ Cheap flights from Boston (BOS) 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 9/20. Fares are subject to change and may not be available on all flights or dates of travel.
BOS — SOF
Oct 11 — Oct 181
Sat 10/11
Sat 10/18
1 adult, Economy
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Cheapflights Tip: The best prices from Boston Logan Intl to Sofia are usually found in October or September, booked 67 days in advance, depart on a Tuesday or Saturday and return on a Thursday

Cheap flight deals from Boston to Sofia

Discover tips and strategies to find the most affordable flight options for your journey from Boston (BOS) 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

$349
(Kiwi.com)

One-way from

$309
(Kiwi.com)

Popular in

June

Cheapest in

October

Average price

$664
From Boston Logan Intl to Sofia
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One-way flight from Boston Logan Intl to Sofia
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Highest demand for flights based on searches. 9% potential increase in price ($88 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($21 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Find flight deals from Boston to Sofia

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

This Kiwi.com deal was found by Cheapflights users on 9/9. 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.
Sun 10/195:05 pmBOS - SOF
1 stop14h 40mMultiple Airlines
Tue 11/47:55 amSOF - BOS
2 stops16h 20mMultiple Airlines
Deal found 9/9$349
This Kiwi.com deal was found by Cheapflights users on 9/9. 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 10/225:10 pmBOS - SOF
1 stop11h 30mMultiple Airlines
Wed 11/52:00 pmSOF - BOS
1 stop11h 35mMultiple Airlines
Deal found 9/9$356
This Kiwi.com deal was found by Cheapflights users on 9/9. 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.
Tue 10/218:05 pmBOS - SOF
1 stop15h 35mLufthansa
Tue 11/42:00 pmSOF - BOS
1 stop11h 35mLufthansa
Deal found 9/9$358
This Kiwi.com deal was found by Cheapflights users on 9/9. 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.
Mon 12/81:38 pmBOS - SOF
2 stops15h 12mAustrian Airlines
Mon 12/226:45 pmSOF - BOS
1 stop26h 20mAustrian Airlines
Deal found 9/9$361
This Kiwi.com 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/98:40 pmBOS - SOF
1 stop14h 40mLufthansa
Tue 12/232:00 pmSOF - BOS
1 stop11h 35mLufthansa
Deal found 9/10$362
This Air France deal was found by Cheapflights users on 9/9. 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 Air France is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/205:20 pmBOS - SOF
1 stop13h 40mAir France
Tue 11/47:10 amSOF - BOS
1 stop16h 10mAir France
Deal found 9/9$366
This Ticket deal was found by Cheapflights users on 9/9. 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 Ticket is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/248:05 pmBOS - SOF
1 stop15h 35mLufthansa
Fri 10/312:00 pmSOF - BOS
1 stop11h 35mLufthansa
Deal found 9/9$367
This British Airways 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 British Airways is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/2810:35 pmBOS - SOF
1 stop15h 35mBritish Airways
Mon 11/105:25 pmSOF - BOS
1 stop27h 55mBritish Airways
Deal found 9/10$369
This Air France deal was found by Cheapflights users on 9/9. 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 Air France is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/211:15 pmBOS - SOF
2 stops17h 45mAir France
Wed 11/57:00 amSOF - BOS
1 stop13h 40mAir France
Deal found 9/9$370
This Air France 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 Air France is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/287:30 pmBOS - SOF
1 stop12h 25mAir France
Tue 11/117:10 amSOF - BOS
2 stops18h 46mAir France
Deal found 9/10$372
This Air France 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 Air France is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/287:30 pmBOS - SOF
1 stop12h 25mMultiple Airlines
Thu 11/137:00 amSOF - BOS
2 stops16h 15mMultiple Airlines
Deal found 9/10$373
This Air France deal was found by Cheapflights users on 9/9. 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 Air France is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/205:20 pmBOS - SOF
1 stop13h 40mMultiple Airlines
Tue 11/47:00 amSOF - BOS
2 stops16h 32mMultiple Airlines
Deal found 9/9$377

Cheapflights Fare Finder

 
Customize your flight search to find flights from Boston 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 Boston to Sofia that are best for you.

Fly from

Boston

Fly to

Sofia

Route

Depart

Return

Price

BostonSofia

BOS - SOF

BOSSOF

Boston Logan Intl

Wed 2/11

7:10 pm-2:05 pm

1 stop11h 55m

Sofia

Wed 2/25

7:00 am-4:20 pm

1 stop16h 20m

$379

BostonSofia

BOS - SOF

BOSSOF

Boston Logan Intl

Tue 10/28

5:00 pm-2:05 pm

2 stops15h 05m

Sofia

Tue 11/11

7:10 am-6:56 pm

2 stops18h 46m

$385

BostonSofia

BOS - SOF

BOSSOF

Boston Logan Intl

Tue 10/21

8:05 pm-11:00 pm

1 stop19h 55m

Sofia

Fri 11/7

7:55 am-2:05 pm

1 stop13h 10m

$392

BostonSofia

BOS - SOF

BOSSOF

Boston Logan Intl

Mon 10/27

9:40 pm-10:45 pm

1 stop19h 05m

Sofia

Tue 11/11

7:55 am-2:05 pm

1 stop13h 10m

$392

BostonSofia

BOS - SOF

BOSSOF

Boston Logan Intl

Sun 10/26

9:40 pm-10:45 pm

1 stop19h 05m

Sofia

Tue 11/11

7:55 am-2:05 pm

1 stop13h 10m

$392

BostonSofia

BOS - SOF

BOSSOF

Boston Logan Intl

Tue 10/28

9:40 pm-6:20 pm

1 stop14h 40m

Sofia

Fri 11/14

7:55 am-2:05 pm

1 stop13h 10m

$392

BostonSofia

BOS - SOF

BOSSOF

Boston Logan Intl

Wed 10/29

9:40 pm-10:45 pm

1 stop19h 05m

Sofia

Fri 11/14

7:55 am-2:05 pm

1 stop13h 10m

$392

BostonSofia

BOS - SOF

BOSSOF

Boston Logan Intl

Sun 10/26

9:40 pm-6:20 pm

1 stop14h 40m

Sofia

Thu 11/13

6:05 am-6:35 pm

1 stop19h 30m

$393

BostonSofia

BOS - SOF

BOSSOF

Boston Logan Intl

Mon 10/27

9:40 pm-6:20 pm

1 stop14h 40m

Sofia

Wed 11/12

2:00 pm-6:35 pm

1 stop11h 35m

$393

BostonSofia

BOS - SOF

BOSSOF

Boston Logan Intl

Sun 10/19

8:05 pm-11:00 pm

1 stop19h 55m

Sofia

Thu 11/6

6:05 am-6:35 pm

1 stop19h 30m

$393

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/11

Showing 1-10 of 18 results
1
2

Best time to book a flight from Boston to Sofia

Have a flexible travel schedule? Discover the best time to fly to Sofia from Boston 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 Boston to Sofia

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

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

The best time to book flights from Boston to Sofia is 67 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 Boston to Sofia?

Currently, November is the cheapest month in which you can book a flight from Boston to Sofia (average of $632). Flying from Boston 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.

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

Find hourly flight availability from Boston 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 September 11, 2025.

When flying from Boston to Sofia, the time of day you fly usually plays a role in the price. Save by searching for a flight in the evening, which can drop the price by up to 21% versus a flight in the morning.

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.
Peruse reviews from past customers who have flown with KLM, United Airlines, and Turkish Airlines from Boston to Sofia to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
KLM
7.8
Good
1,385 reviews

Boarding

7.8

Entertainment

7.2

Comfort

7.7

Food

7.3

Crew

8.4

Overall

7.8

Reviews

1 / 20
4.0
Okay

Mark,Sep 2025

AMS - BHX

Crew and snacks were good, boarding wasn't great as busses were used rather than boarding tunnels. Also endured a one hour delay.
KLM
7.8
Good
1,385 reviews
KLM
7.8
Good
1,385 reviews

Boarding

7.8

Entertainment

7.2

Comfort

7.7

Food

7.3

Crew

8.4

Overall

7.8

Reviews

1 / 20
4.0
Okay

Mark,Sep 2025

AMS - BHX

Crew and snacks were good, boarding wasn't great as busses were used rather than boarding tunnels. Also endured a one hour delay.
United Airlines
7.4
Good
8,937 reviews
KLM
7.8
Good
1,385 reviews

Boarding

7.8

Entertainment

7.2

Comfort

7.7

Food

7.3

Crew

8.4

Overall

7.8

Reviews

1 / 20
4.0
Okay

Mark,Sep 2025

AMS - BHX

Crew and snacks were good, boarding wasn't great as busses were used rather than boarding tunnels. Also endured a one hour delay.
Turkish Airlines
7.3
Good
3,968 reviews
KLM
7.8
Good
1,385 reviews

Boarding

7.8

Entertainment

7.2

Comfort

7.7

Food

7.3

Crew

8.4

Overall

7.8

Reviews

1 / 20
4.0
Okay

Mark,Sep 2025

AMS - BHX

Crew and snacks were good, boarding wasn't great as busses were used rather than boarding tunnels. Also endured a one hour delay.
Lufthansa
6.8
Okay
7,409 reviews
KLM
7.8
Good
1,385 reviews

Boarding

7.8

Entertainment

7.2

Comfort

7.7

Food

7.3

Crew

8.4

Overall

7.8

Reviews

1 / 20
4.0
Okay

Mark,Sep 2025

AMS - BHX

Crew and snacks were good, boarding wasn't great as busses were used rather than boarding tunnels. Also endured a one hour delay.
British Airways
6.7
Okay
7,361 reviews
KLM
7.8
Good
1,385 reviews

Boarding

7.8

Entertainment

7.2

Comfort

7.7

Food

7.3

Crew

8.4

Overall

7.8

Reviews

1 / 20
4.0
Okay

Mark,Sep 2025

AMS - BHX

Crew and snacks were good, boarding wasn't great as busses were used rather than boarding tunnels. Also endured a one hour delay.

Related info for your journey

Find useful and relevant information for your journey from Boston 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 Boston to Sofia?

    United Airlines can get you from Boston to Sofia in just under 19h 55m. Your travel time can differ by up to . The distance between Boston and Sofia is about 4521 mi.

  • What are the cheapest airlines flying from Boston to Sofia round-trip?

    Air France, at $416, was found to be the cheapest airline from Boston to Sofia.Alternate airlines to your destination round-trip include KLM and SWISS. Air France is 48% cheaper than the average price of flights available within the next 90 days to this destination.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Boston 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 Boston to Sofia?

    Currently, November is the cheapest month in which you can book a flight from Boston to Sofia (average of $632). Flying from Boston 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 Boston to Sofia

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

Top 9 airlines flying from Boston to Sofia

Discover the top 9 airlines that operate flights from Boston 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
Air FranceCheapest$416Average$719FlexibilityNo cancel feeOn-time77%
KLMCheapest$432Average$795FlexibilityNo cancel feeOn-time75%
SWISSCheapest$437Average$760FlexibilityNo cancel feeOn-time79%
Austrian AirlinesCheapest$497Average$797FlexibilityNo cancel feeOn-time78%
United AirlinesCheapest$505Average$786FlexibilityNo cancel feeOn-time69%
Turkish AirlinesCheapest$505Average$653FlexibilityNo cancel feeOn-time77%
ITA AirwaysCheapest$505Average$924FlexibilityNo cancel feeOn-time81%
British AirwaysCheapest$510Average$561FlexibilityNo cancel feeOn-time70%
LufthansaCheapest$538Average$876FlexibilityNo cancel feeOn-time76%

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