AirHint found the following cheapest return flights from Chicago (MDW) to Sofia (SOF) in August 2025 (see full year).

Return flights

20 Aug - 05 Sep	KLM
31 Aug - 15 Sep	KLM
16 Aug - 15 Sep	KLM
18 Aug - 27 Aug	Air France
06 Aug - 03 Sep	Porter Airlines (Canada) Ltd
14 Aug - 28 Aug	KLM
24 Aug - 07 Sep	KLM
23 Aug - 21 Sep	KLM
03 Aug - 24 Aug	KLM
10 Aug - 16 Aug	KLM
01 Aug - 17 Aug	KLM

Also check the deals for one-way flights from Chicago to Sofia in August.

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 Chicago to Sofia in August from $740

Return flights