Find cheap airlines flights from Kos to Sofia

You can choose from 1 airlines that fly from Kos to Sofia, including SKY express, AEGEAN has lowest fares on this route.
SKY express logo SKY express
Airlines are determined based on actual purchased flight tickets from Kos to Sofia according to previous 12 months data from Trip.com.

Find flight deals from Kos to Sofia for the next 3 months. Book one way flights from €69 or round trip flights from €131.

Displayed flight fares from Kos to Sofia are based on average prices across airlines for the next 3 months, according to the latest Trip.com database.

Flight Info | Kos to Sofia

The distance between Kos and Sofia is approximately 727.8 km. Based on Trip.com's data travel demand peaks in August. The off-season for travel is November.

Cheapest one-way flight price€69
Cheapest round-trip ticket price€131
Off-season for travelNovember
Peak season for travelAugust
Flight distance727.8 km
Popular airlineSKY express
Flight statistics for the Kos–Sofia route are based on aggregated booking data from Trip.com over the past 12 months.

Frequently Asked Questions

  • What are the cheapest flights from Kos to Sofia (KGS-SOF)?

    Based on Trip.com data, AEGEAN offers one-way fares as low as €69 on Cheapest nonstop routes (e.g. KGS to SOF on Mon, Apr 20), while AEGEAN offers Cheapest nonstop round-trips from €131 departing on Mon, Mar 16 and returning on Fri, Mar 20.
  • At the moment, you can catch a nonstop flight from Kos to Sofia with the following airlines, including: SKY express Selected airlines are based on historical data collected from flight bookings users made on Trip.com within the last 90 days.
  • By analyzing data from all airlines on the Trip.com flight calendar, it looks like the best time to book a flight from Kos to Sofia is around 40 days (6 weeks) in advance, and the best time to fly is usually on Tuesday, Wednesday, and Saturday. Tuesday typically offers the cheapest flights for departure, while Saturday offers the best return deals.
  • To find best deals on flights from Kos to Sofia, you can use various tools on Trip.com:
    · Be flexible with your travel dates to get the cheapest flight deal. Now the cheapest flight deal is on Mon, Apr 20, with one-way flights priced at just €69.
    · Compare airlines strategically. Budget carriers often provide the lowest base fares, while we found the most affordable airline currently operating on this route is AEGEAN.
    · Set up price alerts to easily monitor ticket prices without having to check every day.
    · Check Trip.com flight deals and promo codes frequently.
    · Avoid peak season unless you book very early. It seems the peak season for Sofia travel is around August.
    · Get exclusive promo codes for Trip.com app users.
  • The cheapest months to fly from Kos to Sofia is November, when demand for travel is lower.
  • After crunching the numbers on our March flight calendar, it's currently cheapest to fly from Kos to Sofia on March 20, 2026 with AEGEAN, with prices starting at €75.
  • You can land at any one of the following hubs in Sofia, with Kos Airport to Sofia International Airport (KGS-SOF) is by far the most common option on this route: Sofia International Airport (SOF).
  • The time difference between Sofia and Kos is 0h.
  • Tickets can only be changed or canceled if permitted by airline policy. To submit a change or cancellation request, go to the flight bookings page, select the option to change or cancel your booking, choose the relevant passengers and segment, and submit a request. Please note that additional charges may apply according to the airline ticket policy. However, if the flight has been rescheduled and you would like to change or cancel your ticket, you can submit an involuntary cancellation request. For more details about change and cancellation policies, please check the customer support pages.

Note: Prices shown on this page are estimated lowest price and include all taxes and fees found in the last 24 hours.

Book with no extra fees

Prices displayed in this page are all-inclusive prices (incl. taxes, fuel surcharge, civil aviation development fund, etc) with all fees confirmed before payment. Fees for luggage, meals, WLAN, or other additional services are also included as shown in the flight cards.

Real-time pricing updates

Prices, availability, and travel information on this page were updated within last 24 hours—even in real-time. The more popular the route, the more precise the data.

Change & Cancellation Policy

Trip.com displays flight cancellation and change policies for each flight ticket during the booking process, including fees and applicable conditions. Please check the following scenarios:
Voluntary cancellation/change:
To submit a change or cancellation request, go to the flight bookings page, select the option to change or cancel your booking, choose the relevant passengers and segment, and submit a request. Please note that additional charges may apply according to the airline ticket policy.
Cancellation/change due to a flight schedule change:
If the flight has been rescheduled and you would like to change or cancel your ticket, you can submit an involuntary cancellation request. For more details about change and cancellation policies, please check the customer support pages.