STL - SOF

$547 Find Cheap Flights from St. Louis to Sofia

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 Sofia departing on 2/26. 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 St. Louis to Sofia, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to Sofia, as well as popular online travel agencies
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Everything you should know

Cheapest round-trip
$547
United Airlines
Thu 2/26Mon 3/2
STL - SOF • 2 stops
Cheapest one-way
Multiple Airlines
Thu 1/29
STL - SOF • multi-stop
Top airlines
United Airlines
Cheapest • from $547 (round-trip)
United Airlines
Best reviews • 7.4 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
When to book
3 weeks
in advance
Our data shows that travelers who book at least 3 weeks in advance save around 25% compared to booking last minute.
Insights
Insights
Insights
Insights
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 St. Louis to Sofia (STL-SOF)

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

Thu, Feb 26 - Mon, Mar 2
United Airlines Logo
11:25 am - 10:45 pm
STL
-
SOF
27h 20m
2 stops
United Airlines Logo
6:10 am - 8:26 pm
SOF
-
STL
22h 16m
2 stops
$547United Airlines
Sun, Mar 1 - Sat, Mar 7
Multiple Airlines Logo
6:55 pm - 6:20 pm
STL
-
SOF
15h 25m
2 stops
Multiple Airlines Logo
6:15 pm - 10:51 pm
SOF
-
STL
36h 36m
2 stops
$595Multiple Airlines
Sun, Mar 1 - Sat, Mar 7
Lufthansa Logo
6:55 pm - 10:45 pm
STL
-
SOF
19h 50m
2 stops
Lufthansa Logo
2:25 pm - 1:55 pm
SOF
-
STL
31h 30m
1 stop
$600Lufthansa
Thu, Feb 26 - Mon, Mar 2
United Airlines Logo
2:45 pm - 10:45 pm
STL
-
SOF
24h 00m
2 stops
United Airlines Logo
1:45 pm - 8:23 pm
SOF
-
STL
38h 38m
2 stops
$609United Airlines
Thu, Feb 26 - Mon, Mar 2
United Airlines Logo
9:55 am - 10:45 pm
STL
-
SOF
28h 50m
2 stops
United Airlines Logo
1:45 pm - 8:23 pm
SOF
-
STL
38h 38m
2 stops
$610United Airlines
Sun, Mar 1 - Sat, Mar 7
Lufthansa Logo
3:50 pm - 1:35 pm
STL
-
SOF
13h 45m
1 stop
Lufthansa Logo
2:25 pm - 1:55 pm
SOF
-
STL
31h 30m
1 stop
$614Lufthansa
Wed, May 20 - Wed, May 27
Multiple Airlines Logo
7:30 am - 12:10 pm
STL
-
SOF
20h 40m
2 stops
Multiple Airlines Logo
6:20 am - 1:25 pm
SOF
-
STL
15h 05m
1 stop
$687Multiple Airlines
Wed, May 20 - Wed, May 27
United Airlines Logo
7:30 am - 10:50 pm
STL
-
SOF
31h 20m
2 stops
United Airlines Logo
6:20 am - 8:05 pm
SOF
-
STL
21h 45m
2 stops
$705United Airlines
Wed, May 20 - Wed, May 27
Lufthansa Logo
3:30 pm - 1:25 pm
STL
-
SOF
13h 55m
1 stop
Lufthansa Logo
6:20 am - 1:25 pm
SOF
-
STL
15h 05m
1 stop
$997Lufthansa
Wed, Jul 1 - Tue, Aug 4
Lufthansa Logo
8:25 am - 11:10 pm
STL
-
SOF
30h 45m
2 stops
Lufthansa Logo
6:10 am - 1:25 pm
SOF
-
STL
15h 15m
1 stop
$1,019Lufthansa
Booking Insights

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

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

How far in advance should I book a flight from St. Louis 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 St. Louis 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 St. Louis to Sofia, you should book around 3 weeks before departure, which saves you about 25% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 8 weeks before departure.

Good to know

Cheapest flight$547
Most popular time to fly and prices are also 1% lower on average.
Flight from St. Louis to Sofia

When to book flights from St. Louis to Sofia

Are your dates flexible? Find out the best times to travel from St. Louis 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 St. Louis to Sofia

  • What is the cheapest flight from St. Louis to Sofia?

    In the last 3 days, the lowest price for a flight from St. Louis to Sofia was $547 for a round-trip ticket.

  • Do I need a passport to fly between St. Louis and Sofia?

    Yes, you'll most likely have to show a valid passport before boarding the plane in St. Louis and on arrival in Sofia.

  • Which aircraft models fly most regularly from St. Louis to Sofia?

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

  • Which airline alliances offer flights from St. Louis to Sofia?

    Star Alliance is the only airline alliance operating flights between St. Louis and Sofia.

  • Which is the best airline for flights from St. Louis to Sofia, United Airlines or Lufthansa?

    The two airlines most popular with KAYAK users for flights from St. Louis to Sofia are United Airlines and Lufthansa. With an average price for the route of $847 and an overall rating of 7.4, United Airlines is the most popular choice. Lufthansa is also a great choice for the route, with an average price of $892 and an overall rating of 6.8.

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

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Sofia from St. Louis 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 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 St. Louis with another airline. Booking your flights between St. Louis 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 St. Louis 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 St. Louis up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

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

 
See real verified KAYAK customer reviews for airlines flying from St. Louis 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 St. Louis 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.
7.4
United AirlinesOverall score based on 9215 reviews
8.1Crew
6.6Food
7.3Comfort
7.1Entertainment
7.7Boarding
Airline reviews

In overall it was a good experience, the only down point was that the entertainment screen was working properly.

8.0 ExcellentAnonymous, Jan 2026
ORD - TPA
Read more United Airlines reviews

In overall it was a good experience, the only down point was that the entertainment screen was working properly.

HORRIBLE, my initial flight was cancelled, they made me pay $200 extra dollars and that got cancelled as well! After 6 cancellations I decided to get a refund because I needed to get home to my babies. Out of $1000+ dollars they offered me only $40 in refund! Totally unacceptable! The flight that they cancelled I was able to fly it on another airline. I had to spend $400 on one way tickets just to get home! I’m still getting the runaround.

First class ticket gets you a choice of chips or nuts. . Just like economy Southwest. Also no screen in the seats. This is first class???!

Seated dude next to me even though lots of empty rows. But main thing was we sat on the tarmac after landing for 30 minutes because of, in the words of the dude who sat next to me, “operational incompetence”. We got changing directions about where to pick up gate checked bags. Pilot and flight attendant were awesome though.

The food was terrible this time. Otherwise pleasant, quiet, on-time.

It was a pretty standard flight... until the almost hour and a half spent on the taxi way. I get that the weather has been poor but the delay had nothing to do with the weather and more to do with a plane with several issues tying up the gate. I get that that happens from time to time but this has been EVERY flight I've been on for the past 5 years and I fly 3 to 5 times a year. This isn't just United... it's American, it's Delta. It's an issue with the entire industry. I work for UPS and packages on a cargo plane get better service than people do these days. Anymore I HATE flying.

Flight arrived 30 min early and bag was waiting at the baggage pickup. United Club HNL was one of the nicest in the system

Unfortunately weather delayed our flight waiting for our plane to arrive and due to a little snow time was needed to deice the plane so departure was very delayed and I missed the connecting flight

Very good. Because of the delays with my previous flight, I missed my connection, but I was able to book another flight through the United app easily.

I wish there were outlets to charge my iPhone. The crew was great; we had a female pilot who was great with explaining what was happening and delays,

Service and food were excellent. Incredibly friendly and competent staff. Flight was delayed over and hour and I had to run between terminals to get my connecting flight.

Missed it by a couple minutes and couldn’t find an alternative flight so had to spend the night in DC and after much shuffling from 1 airline to another managed to get a United to Frankfurt.

There were only 2 toilets and one of them did not work in business class. We are not allowed to cross classes so had to wait in line to use the toilets!! The entertainment touch display was finicky and did not work all the time.

We missed our flight. There was not enough time built into the layover to get through immigration, customs, bagclaim, bag rechecking, and the long trip to another terminal and gate. Kayak really screwed up. We took the bus up to Wisconsin and then were picked up in Brookfield by private car. It was lucky we didnt miss the last bus out.

I tried both on line and by calling the Customer Service line to arrange for a special meal as i have food intolerances. I was under the impression from your service representative that I was successful. I was not. I cannot eat spicy foods and get very ill if i eat bell peppers. I could not eat either menu choice and no special meal was actually ordered. ( your representative tried to order it for a flight that did not have meal service!!! - found this out later). Your wonderful cabin crew managed to put together a fruit, salad, roll and cheese tray for me so I had something to eat. WHY WOULD YOU SERVE SPICY FOOD, WITH NO MILDER OPTION,ON AN INTERNATIONAL FLIGHT???

Crew was professional and great, flight was clean. However food was pathetic. I ordered a Hindu meal assuming no meat but they served chicken. Need to be very specific- Hindu meal should be categorize as Vegetarian - no meat or egg. Or it should be specific that we are serving meat.

Late flight Delays Poor service Poor staff Worst airline ever

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.

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

Information on your arrival and departure airports