AirHint found the following cheapest return flights from Boston (BOS) to Sofia (SOF) in October 2025 (see full year).

Return flights

21 Oct - 04 Nov	Air Canada
22 Oct - 05 Nov	Air Canada
15 Oct - 29 Oct	Air Canada
08 Oct - 22 Oct	Air Canada
07 Oct - 21 Oct	Air Canada
15 Oct - 05 Nov	Lufthansa
14 Oct - 28 Oct	Air Canada
06 Oct - 16 Oct	Air Canada
01 Oct - 08 Oct	Air Canada
01 Oct - 15 Oct	Air Canada
01 Oct - 28 Nov	Air Canada
13 Oct - 27 Oct	SWISS
18 Oct - 27 Oct	Air Canada
23 Oct - 06 Nov	SWISS
26 Oct - 09 Nov	Air Canada
09 Oct - 23 Oct	SWISS

Also check the deals for one-way flights from Boston to Sofia in October.

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.

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Cheapest return flights from Boston to Sofia in October from $348

Return flights