STL - SOF

$664 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 9/8. 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

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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Flights 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

Mon, Sep 8 - Mon, Sep 29
United Airlines Logo
7:04 pm - 11:00 pmSTL-SOF
19h 56m2 stops
United Airlines Logo
12:00 pm - 2:27 pmSOF-STL
34h 27m2 stops
$664United Airlines
Find Deal
Wed, Sep 24 - Wed, Oct 15
Lufthansa Logo
7:04 pm - 10:50 pmSTL-SOF
19h 46m2 stops
Lufthansa Logo
6:15 am - 1:30 pmSOF-STL
15h 15m1 stop
$700Lufthansa
Find Deal
Wed, Sep 24 - Wed, Oct 15
Lufthansa Logo
7:04 pm - 10:50 pmSTL-SOF
19h 46m2 stops
Lufthansa Logo
6:15 am - 3:44 pmSOF-STL
17h 29m2 stops
$717Lufthansa
Find Deal
Wed, Sep 24 - Wed, Oct 15
Lufthansa Logo
3:30 pm - 5:50 pmSTL-SOF
18h 20m1 stop
Lufthansa Logo
6:15 am - 1:30 pmSOF-STL
15h 15m1 stop
$902Lufthansa
Find Deal
Mon, Sep 8 - Mon, Sep 29
Lufthansa Logo
7:04 pm - 11:00 pmSTL-SOF
19h 56m2 stops
Lufthansa Logo
6:15 am - 7:09 pmSOF-STL
20h 54m1 stop
$1,032Lufthansa
Find Deal
Wed, Sep 24 - Wed, Oct 15
 Logo
9:15 am - 5:30 pmSTL-SOF
24h 15m3 stops
 Logo
6:00 am - 7:38 pmSOF-STL
21h 38m2 stops
$1,242
Find Deal
Mon, Sep 8 - Mon, Sep 29
Lufthansa Logo
12:35 pm - 11:15 amSTL-SOF
14h 40m1 stop
Lufthansa Logo
6:15 am - 7:09 pmSOF-STL
20h 54m1 stop
$1,271Lufthansa
Find Deal
Mon, Sep 8 - Mon, Sep 29
 Logo
1:00 pm - 3:35 pmSTL-SOF
18h 35m3 stops
 Logo
12:00 pm - 3:18 pmSOF-STL
35h 18m2 stops
$1,315
Find Deal
Wed, Sep 24 - Wed, Oct 15
 Logo
9:15 am - 5:30 pmSTL-SOF
24h 15m3 stops
 Logo
9:15 pm - 4:35 pmSOF-STL
27h 20m3 stops
$1,373
Find Deal
Wed, Oct 22 - Fri, Nov 21
Air Canada Logo
9:15 am - 12:00 pmSTL-SOF
18h 45m2 stops
Air Canada Logo
6:15 am - 9:40 pmSOF-STL
23h 25m3 stops
$5,428Air Canada
Find Deal
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.

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

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

If your flying dates are flexible, you should consider flying to Sofia on a Saturday, as we generally find the cheapest rates on that day for this route. On the other hand, Friday is the most expensive day to fly from St. Louis to Sofia. For your return ticket, we recommend flying on a Wednesday and avoiding Tuesdays for the best deals.

What is the cheapest month to fly from St. Louis to Sofia?

To calculate monthly average prices, KAYAK takes all prices for each month 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 median of all values for each month.

The cheapest month for flights from St. Louis to Sofia is February, where tickets cost $640 (return) on average. On the other hand, the most expensive months are June and October, where the average cost of round-trip tickets is $1,456 and $1,319 respectively.

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 5 weeks before departure, which saves you about 36% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 22 weeks before departure.

Good to know

Low seasonJanuary
Cheapest flight$664
Best time to beat the crowds with an average 24% drop in price.
Most popular time to fly and prices are also 7% 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 $664 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 $936 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 $1,016 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 8904 reviews
7.7Boarding
6.6Food
8.1Crew
7.1Entertainment
7.3Comfort
Airline reviews

Terrible. Delayed 7 hours, and cancelled the flight, leaving me stranded and out of pocket $500 for an alternative last minute flight

2.0 MediocreV, Jul 2025MIA - EWR
Read more United Airlines reviews

Terrible. Delayed 7 hours, and cancelled the flight, leaving me stranded and out of pocket $500 for an alternative last minute flight

Was on time until within 1 hour of flight-how does that happen? Staff very friendly.

the delay for 3 hours was understandable due to weather conditions but the flight should’ve provided some on flight compensations or at least provide more food.

Weather delay in Chicago?. No sense of urgency to make connection in Chicago for our connecting flight that wasn't delayed. Connection was missed.

Ridiculous boarding. Enter the gate, walk down a staircase with bags, exit a building, get on a crowded bus, dropped off a few meters away from the aircraft, walk with bags to another set of stairs to board the aircraft. And all that during a pouring down rain, and with children. Ridiculous!!!

Our flight was understandably diverted to a small regional airport in Laramie, Wyoming due to weather conditions, which I fully recognize and appreciate. However, the low rating stems from the experience that followed: passengers remained on board for over an hour without the option to deplane and stretch, despite the aircraft being stationary. Although the pilot opened the cabin door, only he was permitted to exit. Meanwhile, passengers grew increasingly uncomfortable as warm summer air entered the cabin through the open door, and being in the second row meant we were impacted immediately. While the flight attendants made efforts to keep everyone at ease, I believe allowing passengers to deplane briefly, given the extended delay, would have significantly improved the overall experience.

I never flew. Flight was canceled. DIA worst airport in the country. Avoid at all costs.

I learned that seating towards the end of plane that a line forms for the restroom and people use your chair as a hand railing, bumping your seat consistently. I was seated in the aisle. I think that next time if I am towards the back row I would want to sit in the middle or window seat.

The best airline I have ever travel , really good customer service, attention and service !!

United could have one single once of customer service. No human United employee would help me with the invalid mileage plus number, they said I had to speak with the computer.

Our flight was delayed for over an hour due to weather, and it had already been a long travel day. However, the crew was calm and compassionate, listening to every complaint with genuine concern. They got us home safely without incident, in spite of all of the obstacles. I’m grateful.

Hate their old flights, boatding, food and services. Very poor quality

Insulting. Lufthansa flight from Munich to EWR had us getting our luggage when we were told in Florence that it would follow us to Indianapolis. It did not. Then very slow security in EWR caused me and three other passengers from Lufthansa flight from Munich to miss the boarding closure. Behind me were two elderly grandparents and their ten year old grandson. We were all refused entry on a plane to Indy that was still at the gate. The doors had not even closed inside the terminal yet. No apologies or compensation offered. Not even a meal voucher let alone a free hotel stay for our inconvenience. I m not sure what the other three passengers behind me did ( they were elderly with a grandson, recall), but I stated 12 hours overnight in a chilly EWR airport until next flight to Indy at 850 next morning.

The food could be better, more snacks. And have some plugs to chargue the phone.

The pasta in the evening meal was tasteless. Otherwise, the flight was okay.

Everything was really great just The aircraft was too old and sounded it will break during takeoff

Seating was average for a first class seat. It very modern. I expected better.

Flight was a little late. The crew was courteous, food ok

Bad! Disaster!! The LH419 was cancelled after 4 hrs on board with no AC and no toilets

Poor food on flight between Toronto and Stockholm Airport Toronto too crowded

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

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