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

Return flights

17 Sep - 27 Sep	Ryanair
16 Sep - 20 Sep	Ryanair
17 Sep - 20 Sep	Ryanair
19 Sep - 21 Sep	Vueling Airlines
20 Sep - 27 Sep	Vueling Airlines
03 Sep - 17 Sep	Vueling Airlines
19 Sep - 26 Sep	Vueling Airlines
15 Sep - 22 Sep	Wizz Air Malta
20 Sep - 23 Sep	Vueling Airlines
09 Sep - 15 Sep	Ryanair

Also check the deals for one-way flights from Lisbon 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 Lisbon to Sofia in September from $174

Return flights