BOS - SOF

$284 Find Cheap Flights from Boston to Sofia - Compare and Save

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Boston to Sofia departing on 8/4. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

KAYAK searches hundreds of travel sites at once for deals on flights to Sofia

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Boston to Sofia.
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Boston to Sofia.
Travelers love KAYAK
41,299,237 searches in the past 7 days on KAYAK

Save 21% or moreCompare multiple travel sites with one search.

Track pricesNot ready to book? Create a price alert for when prices drop.

Bundle and saveSave money when you bundle your flight + hotel.

Filter your dealsChoose cabin class, free Wi-Fi and more.

Everything you should know

Cheapest round-trip
$798
Typical prices: $731-$437
Air France, KLM
Thu 9/3Sun 9/13
BOS - SOF • 1 stop
Cheapest one-way
$284
Typical prices: $424-$501
Multiple Airlines
Tue 8/4
BOS - SOF • 3 stops
Top airlines
Cheapest • from $798 (round-trip)
Best reviews • 7.8 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
Nonstop flights
Not available
There are currently no direct flights between Boston and Sofia. You'll need at least 1 connection.
Insights
Insights
Insights
Insights
Top layover airports
Cheapest • Avg $547 (round-trip)
Shortest trip • 10h 57m (one-way)
Insights
Insights
Insights
Insights
When to book
in advance
Our data shows that travelers who book at least 3 weeks in advance save around 12% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
Cheapest • 28% price drop
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
Start a new search
KAYAK searches 100s of sites at once to find you the best travel deals.
We hope you love your trip to Sofia!
Flight Deals
Booking Insights
Flight Deals

Cheap Flights from Boston to Sofia (BOS-SOF)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Boston to Sofia that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Boston to Sofia

Thu, Sep 3 - Sun, Sep 13
Multiple Airlines Logo
9:45 pm - 2:00 pm
BOS
-
SOF
33h 15m
1 stop
Multiple Airlines Logo
7:00 am - 4:35 pm
SOF
-
BOS
16h 35m
1 stop
$798Multiple Airlines
Tue, Jul 7 - Tue, Jul 14
Multiple Airlines Logo
4:45 pm - 9:15 pm
BOS
-
SOF
21h 30m
2 stops
Multiple Airlines Logo
11:25 pm - 2:45 pm
SOF
-
BOS
22h 20m
2 stops
$799Multiple Airlines
Mon, Oct 26 - Sun, Nov 8
Austrian Airlines Logo
1:30 pm - 11:50 am
BOS
-
SOF
16h 20m
2 stops
Austrian Airlines Logo
7:55 am - 1:30 pm
SOF
-
BOS
12h 35m
1 stop
$800Austrian Airlines
Thu, Sep 3 - Sat, Sep 12
Lufthansa Logo
8:05 pm - 6:40 pm
BOS
-
SOF
15h 35m
1 stop
Lufthansa Logo
6:10 am - 5:40 pm
SOF
-
BOS
18h 30m
1 stop
$801Lufthansa
Tue, Oct 13 - Mon, Oct 26
Austrian Airlines Logo
5:10 pm - 6:10 pm
BOS
-
SOF
18h 00m
1 stop
Austrian Airlines Logo
6:45 pm - 6:13 pm
SOF
-
BOS
29h 28m
2 stops
$802Austrian Airlines
Sat, Sep 5 - Mon, Sep 21
Air Canada Logo
10:40 am - 6:40 pm
BOS
-
SOF
25h 00m
2 stops
Air Canada Logo
6:10 am - 9:26 pm
SOF
-
BOS
22h 16m
2 stops
$803Air Canada
Sat, Oct 3 - Sat, Oct 17
Turkish Airlines Logo
9:50 pm - 8:45 am
BOS
-
SOF
27h 55m
1 stop
Turkish Airlines Logo
3:50 pm - 7:55 pm
SOF
-
BOS
35h 05m
1 stop
$804Turkish Airlines
Fri, Sep 18 - Sun, Sep 27
Multiple Airlines Logo
8:50 pm - 11:40 am
BOS
-
SOF
31h 50m
3 stops
Multiple Airlines Logo
4:00 pm - 6:50 pm
SOF
-
BOS
33h 50m
3 stops
$805Multiple Airlines
Thu, Aug 13 - Sun, Aug 30
United Airlines Logo
8:05 pm - 11:15 pm
BOS
-
SOF
20h 10m
1 stop
United Airlines Logo
6:10 am - 7:19 pm
SOF
-
BOS
20h 09m
2 stops
$806United Airlines
Thu, Aug 20 - Sat, Sep 5
Multiple Airlines Logo
5:10 pm - 2:00 pm
BOS
-
SOF
13h 50m
1 stop
Multiple Airlines Logo
7:00 am - 4:13 pm
SOF
-
BOS
16h 13m
2 stops
$807Multiple Airlines
Booking Insights

KAYAK's insights & trends for Boston to Sofia flights

Get data-powered insights and trends into flights from Boston to Sofia to help you find the cheapest flights, the best time to fly and much more.

How much is a round-trip flight from Boston to Sofia?

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from Boston to Sofia departing in September.

What is the cheapest month to fly from Boston to Sofia?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Boston to Sofia, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Boston to Sofia is February, where tickets cost $460 (return) on average. On the other hand, the most expensive months are May and June, where the average cost of round-trip tickets is $1,002 and $910 respectively.

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

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Boston to Sofia, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from Boston to Sofia, you should book around 3 weeks before departure, which saves you about 12% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 26 weeks before departure.

Good to know

Low seasonNovember
Cheapest flight$284
Best time to beat the crowds with an average 25% drop in price.
Most popular time to fly with an average 9% increase in price.
Flight from Boston to Sofia

When to book flights from Boston to Sofia

Are your dates flexible? Find out the best times to travel from Boston to Sofia based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking flights from Boston to Sofia

  • What are the layover options on the flight route from Boston to Sofia?

    Your layover will automatically depend on the airline you’re traveling with because each airline on this route has its preferred airport for layovers. For example, Turkish Airlines has all its layovers on this route scheduled for Istanbul. Similarly, Lufthansa has its layovers scheduled for Frankfurt or Munich while SWISS Airlines is scheduled for Zurich.

  • Do I need a visa to fly to Sofia?

    As it stands, U.S. citizens traveling to Bulgaria are not required to carry visas on entry as long as they are traveling on a regular passport and don’t plan on staying for longer than 90 days. In fact, the only mandatory requirement is your passport, with a validity of at least three months beyond the departure date from Bulgaria and one blank page for entry stamps.

  • Is public transport available from Sofia International Airport (SOF)?

    Access to the city center from Sofia Airport is possible through a range of options including bus, metro, and taxi. Taking a taxi is the most convenient although the bus and metro offer an affordable option. The metro in particular is a faster option and typically operates round the clock at intervals of fifteen minutes. To catch the metro, head over to the Airport Metro Station located in Terminal 2 and take the Metro line M2, which leads directly to the city center station Serdika.

  • Which is the most sustainable airline flying this route?

    In these modern times, it is pivotal that we think about the environment. While flying is by no means a sustainable way to travel, there are measures we can take to make our trips more sustainable, and it starts with using a sustainable airline. Lufthansa and American Airlines are a few of the airlines serving this route that have already adopted the use of Sustainable Aviation Fuel.

  • What is the cheapest flight from Boston to Sofia?

    In the last 5 days, the lowest price for a flight from Boston to Sofia was $284 for a one-way ticket and $798 for a round-trip.

  • Do I need a passport to fly between Boston and Sofia?

    Yes

  • Which airports will I be using when flying from Boston to Sofia?

    When flying out of Boston you will be using Boston Logan Intl. You will be landing at Sofia, also known as Sofia.

  • Which aircraft models fly most regularly from Boston to Sofia?

    We unfortunately don’t have that data for this specific route.

  • Which airline alliances offer flights from Boston to Sofia?

    oneworld, SkyTeam, and Star Alliance are the airline alliances operating flights between Boston and Sofia, with oneworld being the most commonly used for this route.

  • What is the most popular layover when flying to Sofia from Boston?

    Frankfurt am Main is the most popular layover city among KAYAK users traveling from Boston to Sofia.

  • Which is the best airline for flights from Boston to Sofia, KLM or Austrian Airlines?

    The two airlines most popular with KAYAK users for flights from Boston to Sofia are KLM and Austrian Airlines. With an average price for the route of $545 and an overall rating of 7.8, KLM is the most popular choice. Austrian Airlines is also a great choice for the route, with an average price of $639 and an overall rating of 7.6.

  • How does KAYAK find such low prices on flights from Boston to Sofia?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Boston to Sofia.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Boston to Sofia?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Sofia from Boston is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Boston to Sofia?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Sofia with an airline and back to Boston with another airline. Booking your flights between Boston and SOF can sometimes prove cheaper using this method.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Boston to Sofia?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Sofia from Boston up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

KAYAK’s top tips for finding a cheap flight from Boston to Sofia

  • Business travelers looking to work while flying should book their flights with Lufthansa. It provides Wi-Fi to all passengers, allowing you to browse the internet, send emails, and check your social media while flying.
  • To get access to an airport lounge during your layover, consider booking your flight with an airline that has a lounge at the airport. For example, when you book with Lufthansa, you can access the Lufthansa Senator Lounge during your layover at Frankfurt Airport.
  • When you book an economy-class ticket with United Airlines, you can be upgraded to the next class at a lower cost compared to what you would’ve paid if you booked a first-class ticket from the get-go.
  • If you have booked your flight with Turkish Airlines, consider upgrading with the EcoFly promotion and get two checked bags plus a carry-on inclusive of your ticket instead of just one carry-on bag.
  • A quick way into Boston Logan International Airport (BOS) from downtown Boston is via taxi. They are available at every corner of the city and will take you directly to the airport terminal. When rush hour traffic is a problem, the Blue Line from South Station offers a great alternative.

Reviews of the top 5 airlines serving from Boston to Sofia

 
See real verified KAYAK customer reviews for airlines flying from Boston to Sofia. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Boston to Sofia? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
7.8
KLMOverall score based on 1527 reviews
8.4Crew
7.7Comfort
7.3Food
7.8Boarding
7.2Entertainment
Airline reviews

As always, it’s a pleasure to travel with KLM. It is one of my favorite airlines.

10.0 ExcellentGeorge, May 2026
OTP - AMS
Read more KLM reviews

As always, it’s a pleasure to travel with KLM. It is one of my favorite airlines.

There were no charge points for phones on the economy seats. The seats were comfortable overall. Food was okay.. flight was on time

The crew were unprofessional with a racist element. I was physically abused as well from one of the crew members

Crew is not the cheerful type. very slow meal service (this is their style as have flown this many times)

Empty seats next to me - wish it had been for a longer flight!!

Flight was on time, staff are friendly and helpful onboard.

They forgot to serve food and the crew was very unfriendly. Never experienced such a bad KLM flight. Usually fly from Toronto. New York was different.

The immigration hall in Amsterdam was understaffed, so passport checking was slower than it should be for a major airport. They need to get the automatic readers up and running for non EU passport holders. Waiting in line after a long flight feels a bit abusive.

Over 1 Hr delay. No APU so no AC on ground. Plane was hot during boarding and then they closed the doors over 20 minutes before engine start so interior of plane was steamy hot and stuffy. Could have been helped by opening doors until ready to depart.

KLM remains a quality flag carrier airline which maintains its standards whilst all their competitors are lowering theirs.

I love Air France. This was another great experience despite a slight delay in the departure. The time was made up on flight. I would take AirFrance again when traveling to the far East. Merci beaucoup.

Everything is good except the seats are tightened no rooms for the legs,

The flight crew was exceptionally friendly and helpful. Also the seats were comfortable and roomier than many other airlines.

The plane's pilots, including the captain himself, thanked me for the flight. I know it's just marketing, but it was really nice to see these people. It's a great idea. Airplane food is never "good," but the entire crew and flight organization were top-notch. I really liked Delta, and I think I've traveled all over the world, and that was something new for me. Maybe even the old planes, the B767, but next time I have a choice, Delta will be my first choice. Thank you, a satisfied passenger :)

Middle seats SUCK!!!! I paid more money than I should have because of your terrible site Kayak.com. I'll try to use your competitors going forward. I am so disappointed you would play off business class.com as business class seats

The boarding was efficient. The entertainment system was a bit unstable but Air France has a good selection of movies.

They lost my bag and I still haven’t received it yet

Communication on the delay, rebooking and how to get a hotel was poor. Mails, airport check-in and transfer desk said different things.

Safe and stable made me sleepy and I slept and dreamt 😂😂😂😂

Food was really mediocre for premium economy in comparison to other airlines… the crew was nowhere to be found… 14 hour flight…

Entertainment system is okay, flight attendants were ok. Leg space very narrow, I couldn’t get what I wanted to eat, dinner nor breakfast.

Excellent experience with business class area. Staff was attentive and food was amazing. Only one bathroom for business class which was logistically difficult for the staff while preparing meals. Need to offer fluids with meals. I did not get enough water to drink. But overall I rate it 5 star.

On time, great food, good drink selection! Only down was alcohol-free lounge. Lufthansa had a much better offering!

Be honest of what you sell: This was sold as Business Class on all three legs, while the JetBlue plane didn't even have business class seats, and wanted $164 for extra legroom seats.

Seat assignments for family traveling with 2 children. Loud crowd during sleep time

It was crowded… the bathrooms dirty and smelly. The seats have been made even smaller.

delayed to take off from detroit by 3 hours lost baggage in istanbul and now in venice without baggage

Seats were very tight with poor legroom - and I am average height. During the 12 hour flight, tiny paper cups of drinks we're only offered during the super and breakfast services, with the crew nowhere to be seen in between. One of the bathrooms was out of order, leading to long lines waiting to use the remaining two available to the economy class passengers.

short flight but we still got a very nice lunch and the crew did an excellent job in taking care of us

For that price on Business class, I expected to have the pod seats. These were configured as 2/3/2 and my seat mate talked half the flight with a friend across the isle, loudly. Very uncouth.

Smooth travel. Immediate update prior flight delay so I can arrange myself properly without too rush.

Everything was the best it could be. Crew found me with pre- ordered food. Excellent experience!

Improve the food offerings and cabin seating. My wife would prefer to fly another airline, even with a connection for a more comfortable trip. A 737-8 should not be scheduled for a 6 hour segment, which turned into 7.5 hours due to the origin ground delay.

Packed flight, which makes it tough on crew and boarding staff (and the customers of course). But this was great boarding, clear instructions, etc. Traveling on the weekends are always fraught with danger as you have families and less frequent flyers thus more confusion. But this flight went as planned.

Destroyed my suitcase. Tired of talking about it. Cancelling my unite mileage plus account.

Read the fine print. This was my flight home. I booked my flight for the quickest way home. Had a carry-on and a personal item. Same as my outbound flight. Apparently I needed to pre-pay extra for my carry-on. When I checked in, I was told that I had to check it. I said I’ll pay for it, and was told that this wasn’t an option anymore. They said I still had to pay $50 to check my carry-on. I told them I’ll pay whatever to just carry it in as intended. I was not allowed, so eventually I paid $50 to check my carry-on under a plane that was half full, with overhead compartments that were even less full. My white carry-on suitcase was practically destroyed getting from Idaho falls to Denver to Orange County. The low price air fair was a bait and switch. Got me to the gate, made me pay extra, then didn’t even allow me to pay for a carry on. Not to mention that I paid the $8 for WiFi that didn’t work. All to get my suitcase destroyed. I don’t think I’m going to even keep my Untied mileage plus membership and card. Apparently, membership does not have its privileges for this one.

The flight was delayed, they didn’t even have water for the toilets or for drinks

Even through the flight was delayed due to storms near IAH The flight was great! The crew was so hospitable and professional

I flew from Santa Fe to Denver to catch a flight to London and the transfer of my luggage on arrival at Denver to the London flight worked perfectly. The crew on the ground and on board for the London flight were so friendly and efficient.

Boarded early; and arrived home 40 mins early. After a long flight, it’s nice to be back home early. These flights have no amenities; no snacks. So need to bring your own

Put me on standby; flight was late; missed my connecting flight; disaster

Flight attendants were fine, seats a bit hard but I use a cushion for extra support. The only issue was it was a bit too cool and I needed to ask for and received and extra blanket. I survived!!!

Very few things and/or people are excellent. It was very good.

Extremely uncomfortable seats. Experience was like a Frontier Airlines flight. Would not fly it again.

Very, very tight legroom. They must’ve jammed in an additional few rows of seat seating. Denver to Munich was the least legroom I’ve ever had on any flight, let alone a multi hour international journey. I will not take that flight again.

In my first flight with Air Canada we sat in the plane for 4:00pm to 6:30pm. Finally we were asked to get off the plane and we were told the flight was cancelled after 7:00pm There was o clear explanation of what was the problem. I was booked without my permission on a Delta Flight at 7:30pm that was leaving at 8:00pm and I still had to go get my luggage(my final destination was Rome with one stop in Toronto. The luggage claim for Canada was closed so had to return to finally get it on the luggage belt.. Of course I missed the Delta flight and all the next day flights were booked. I also lost what I paid for my stay in Rome because I did nt cancel in time. A complete nightmare.

Good food, overall very comfy. The flight was full so obviously not optimal, but it is what it is.

Perfect airline, super friendly, great service, tasty food. Would fly again.

Parents with permanently crying baby on board. Neither parents nor crew did anything to calm the baby. The food was extremely disappointing. Seafood stew was very, very small! Not even appetizer size! Seat had a gap in the back. Had to use a pillow to fill it.

Food choices limited & not enticing Seats quite uncomfortable & difficult to control

Everything you need to know for your flight from Boston to Sofia

Information on your arrival and departure airports