AirHint found the following cheapest return flights from Cologne (CGN) to Sofia (SOF) in September 2025 (see full year).

Return flights

29 Sep - 17 Oct	Ryanair	direct
29 Sep - 10 Oct	Ryanair	direct
29 Sep - 20 Oct	Ryanair	direct
22 Sep - 10 Oct	Ryanair	direct
26 Sep - 17 Oct	Ryanair	direct
26 Sep - 10 Oct	Ryanair	direct
19 Sep - 10 Oct	Ryanair	direct
22 Sep - 25 Sep	Ryanair
05 Sep - 12 Sep	Ryanair
15 Sep - 29 Sep	Ryanair	direct
12 Sep - 26 Sep	Ryanair
16 Sep - 18 Sep	Ryanair
15 Sep - 19 Sep	Ryanair	direct
26 Sep - 29 Sep	Ryanair
24 Sep - 29 Sep	Ryanair
15 Sep - 15 Sep	Ryanair
15 Sep - 26 Sep	Ryanair	direct
29 Sep - 13 Oct	Ryanair	direct
26 Sep - 03 Oct	Ryanair
29 Sep - 06 Oct	Ryanair	direct

Also check the deals for one-way flights from Cologne to Sofia in September.

The deals are updated regularly. The prices may go up as tickets are purchased by other travellers. Only the cheapest flights are offered. Select a price to book and secure these cheap prices.

Book a cheap hotel in Sofia

Cheap car rent in Sofia

Cheapest return flights from Cologne to Sofia in September from 72€

Return flights