$542 Find Cheap Flights from St. Louis to Bulgaria

This is the cheapest round-trip flight price found by a KAYAK user in the last 72 hours by searching for a flight from St. Louis to Bulgaria departing on 1/30. 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

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Book Cheap St. Louis to Bulgaria Plane Tickets

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from St. Louis to Bulgaria 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 St. Louis to Bulgaria

Fri, Jan 30 - Tue, Feb 3
United Airlines Logo
6:40 pm - 6:20 pm
STL
-
SOF
15h 40m2 stops
United Airlines Logo
6:00 am - 3:15 pm
SOF
-
STL
41h 15m2 stops
$542United Airlines
Fri, Jan 30 - Tue, Feb 3
United Airlines Logo
3:50 pm - 1:35 pm
STL
-
SOF
13h 45m1 stop
United Airlines Logo
6:00 am - 3:15 pm
SOF
-
STL
41h 15m2 stops
$550United Airlines
Fri, Jan 30 - Tue, Feb 3
United Airlines Logo
6:40 pm - 6:20 pm
STL
-
SOF
15h 40m2 stops
United Airlines Logo
6:00 am - 8:58 pm
SOF
-
STL
22h 58m2 stops
$620United Airlines
Wed, Feb 4 - Wed, Feb 11
Multiple Airlines Logo
10:10 am - 1:50 pm
STL
-
SOF
19h 40m3 stops
Multiple Airlines Logo
6:10 am - 3:29 pm
SOF
-
STL
41h 19m2 stops
$636Multiple Airlines
Wed, Feb 4 - Wed, Feb 11
Air Canada Logo
10:10 am - 1:50 pm
STL
-
SOF
19h 40m3 stops
Air Canada Logo
6:10 am - 5:43 pm
SOF
-
STL
19h 33m3 stops
$806Air Canada
Fri, Jun 19 - Mon, Jul 6
Multiple Airlines Logo
7:25 am - 12:55 pm
STL
-
SOF
21h 30m2 stops
Multiple Airlines Logo
2:20 pm - 1:25 pm
SOF
-
STL
31h 05m1 stop
$1,150Multiple Airlines
Fri, Jun 19 - Mon, Jul 6
British Airways Logo
4:23 pm - 8:20 pm
STL
-
SOF
43h 57m2 stops
British Airways Logo
8:00 pm - 8:14 pm
SOF
-
STL
32h 14m2 stops
$1,201British Airways
Fri, Jun 19 - Mon, Jul 6
Multiple Airlines Logo
7:25 am - 12:55 pm
STL
-
SOF
21h 30m2 stops
Multiple Airlines Logo
4:05 pm - 4:26 pm
SOF
-
STL
32h 21m2 stops
$1,228Multiple Airlines
Fri, Jun 19 - Mon, Jul 6
Lufthansa Logo
6:49 pm - 12:10 pm
STL
-
SOF
33h 21m2 stops
Lufthansa Logo
6:20 am - 1:25 pm
SOF
-
STL
15h 05m1 stop
$1,268Lufthansa
Fri, Jun 19 - Mon, Jul 6
Multiple Airlines Logo
10:00 pm - 2:05 pm
STL
-
SOF
32h 05m1 stop
Multiple Airlines Logo
3:20 pm - 7:30 pm
SOF
-
STL
36h 10m1 stop
$1,319Multiple Airlines
Booking Insights

KAYAK's insights & trends for St. Louis to Bulgaria flights

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

What’s the cheapest day of the week to fly from St. Louis to Bulgaria?

The average price of all round-trip flights from St. Louis to Bulgaria clicked on KAYAK for each day over the last 12 months.

If you are looking for a flight deal from St. Louis to Bulgaria, look for departures on Saturdays and avoid leaving on a Friday, as it's usually the priciest day. When flying back from Bulgaria, Wednesday is the cheapest day to fly and Tuesday is the most expensive.

How far in advance should I book a flight from St. Louis to Bulgaria?

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from St. Louis to Bulgaria, 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 St. Louis to Bulgaria, you should book around 3 weeks before departure, which saves you about 17% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 6 weeks before departure.

Good to know

Cheapest flight$542
Most popular time to fly with an average 3% increase in price.
Flight from St. Louis to Sofia

FAQs - booking Bulgaria flights

  • How does KAYAK find such low prices on flights from St. Louis to Bulgaria?

    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 St. Louis to Bulgaria.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from St. Louis to Bulgaria?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight from St. Louis to Bulgaria 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 St. Louis to Bulgaria?

    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 from St. Louis to Bulgaria with an airline and back with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from St. Louis to Bulgaria?

    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 from St. Louis to Bulgaria up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • What is the cheapest time of day to fly to Bulgaria?

    The cheapest time of day to fly to Bulgaria is generally in the morning, when round-trip flights cost $1,199 on average. Morning departures are around 10% cheaper than evening flights, on average. The most expensive time of day to fly to Bulgaria is generally in the evening, which is peak travel time and where the average cost of a ticket is $1,335.

Reviews of the top airlines flying from St. Louis to Bulgaria

 
Need help choosing which airline to fly with from St. Louis to Bulgaria? 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.
7.4
United AirlinesOverall score based on 9106 reviews
7.7Boarding
7.3Comfort
7.1Entertainment
6.6Food
8.1Crew
Airline reviews

Gate agent at Frankfurt was terrible. She denied PRE boarding even as it was printed on the boarding pass. Refused to look at the boarding pass and literally shouting for no reason. Frankfurt airport has horrible and rude staff who avoids trying to answer any question at all. Overall, horrible experience.

2.0 MediocreAnonymous, Dec 2025
ATL - FRA
Read more United Airlines reviews

Gate agent at Frankfurt was terrible. She denied PRE boarding even as it was printed on the boarding pass. Refused to look at the boarding pass and literally shouting for no reason. Frankfurt airport has horrible and rude staff who avoids trying to answer any question at all. Overall, horrible experience.

The Crew and the food was the worst I ever had in Business Class. First they told us there were no space for carry on. It was plenty of space over our 2 row seats, we had to ask to let us travel with it which was accepted. They were aware that we had to run for the connection due to the previous flight delay. Have us one hour waiting for more customers and not even offer a glass of water. Then started the service and they started to serve other passengers drinks in business and did not offer any drinks until they serve our pre ordered meal and I ask for something to drink. I had to wait until they finished to serve all passengers until Inget something. The crew was the worts I ever had for Business Class in my life.

Very turbulent trip made it pretty bearable, plus the lack of refreshments served and the lack of any air conditioning before takeoff which took an hour or more.

Flight was late - I was downgraded from first class to coach

Not good - outbound flight was delayed and missed my connection even though I got to the gate after running through the airport - the agent would not let me on because the door was closed (flight had not left). There was no notification from United - overall experience was very disappointing. Additionally, I was downgraded from first class to coach on the alternative flight

The flight was on time. I generally don’t drink or eat on short flights and the seats were good and the flight attendants were friendly. That’s all I expect

It was nice to have gotten up upgraded to first class with a meal on a three hour flight

Not great experience - we were super late boarding due to issues with aircraft. Then when we finally all got onboard and seated and they started taxiing out to the runway they just stopped then turned around and went back to the airport. Apparently the crew “ran out of time” to legally fly us. They mentioned that they were about 2 minutes away from taking off. I understand the rules and safety but kinda wonder why they would have bothered boarding us in the first place? Had to go all the way back and de plane and then wait in a HUGE line to get a hotel (this is somewhere around 2:30am) finally got to hotel by Uber (no shuttle after 20min so gave up) and they ended up putting us all back on the same aircraft at 10am next morning so got about 2.5 hours sleep. They did give us. $250 credit, but it was a São Paulo Brazil flight out of Dulles. The flight and everything was fine.

United overall experience is great these days. Airport experience was very organized. Staff on flight were great. App and information as good as it gets.

United have really come back. Airport and boarding process is clear and good, app and information also very good

Ground staff and cabin crew were excellent. Flight was perfectly on time. Zero issues.

Even after a delay, getting off the ground, thanks for keeping me safe, the airline made certain that my connecting flight was rebooked to get me to my final destination. It was actually rebooked twice, and my luggage still managed to meet me. The airline gave me a credit for food and beverage to be used at the airport vendors, regretfully, the credit did not transfer to my final boarding pass. Oh, well…

Trip was smooth, good drew, average meal, almost cold coffee. Excellent landing. Did not enjoy going down the stairs, walking to the gate, walking up the stairs, going a long walk to the exchange gate, and going down the stairs again to be bussed all the way where we originally landed to take our next flight! Over all an average experience. Thank you.

I booked extra leg room, due to seat neighbor i now consider extra shoulder and arm room as well. Seems like the seats shrink in width now The crew was very friendly and professional ( 100%). Food was good not great, breakfast was bad, a dry slice of bread would have been better. Facilities clean.

Luggage transfer in Chicago was not performed in time. I received my luggage at my destination two days later.

love the crews and my only problem was the delay at Frankfurt was very bad. I have travelled with Lufthansa for over 30 years now and this was cost me some planned business appointment

The flight delay made the connection a bit tight but that's outside the flight crew's control.

We just made it to our connecting flight. A long, long speed walk!

We didn't get the coffee with breakfast in the morning.. 30 mins lazer I asked flight attendant why don't we get coffee now at least.. after the breakfast..she said that captain announced possible turbulences fee minutes ago, which didn't ecplain why we didn't get it with the breakfast..breakfast was very poor btw..just little pastry which you can eat in 4 little bites. Turbulences fortunately didn't even happen.. but we didn't get that more than necessary coffee in the morning after the night flight with very poor sleep.. They just served breakfast 1 hour afzer we took off..at like 11 PM.. that doesn't make sense at all.. Also, flight attendants weren't very nice..they looked like they're not happy with their job.. :/

Lufthansa still has a good level of quality compared to US airlines, especially with respect to (1) food quality - actually tasty, (2) good French red wine - free, (3) good movie selection. Also my ticket price includes 1 free check-in luggage, while some other budget airlines sneak in an extra $150 for a checkin.

Everything you need to know for your flight from St. Louis to Bulgaria

Information on your arrival and departure airports