AirHint found the following cheapest return flights from Chicago (ORD) to Istanbul (SAW) in October 2025 (see full year).

Return flights

12 Oct - 22 Oct	Austrian Airlines
08 Oct - 22 Oct	Spirit Airlines
12 Oct - 13 Nov	Frontier Airlines
31 Oct - 10 Nov	LOT
12 Oct - 14 Nov	TAP
31 Oct - 14 Nov	LOT
31 Oct - 09 Nov	LOT
28 Oct - 04 Nov	Lufthansa
12 Oct - 15 Nov	TAP
08 Oct - 13 Oct	SWISS
18 Oct - 22 Oct	Frontier Airlines
13 Oct - 08 Nov	Spirit Airlines
19 Oct - 08 Nov	Spirit Airlines
13 Oct - 15 Nov	Spirit Airlines
13 Oct - 28 Oct	Spirit Airlines
21 Oct - 28 Oct	Austrian Airlines
04 Oct - 25 Oct	Spirit Airlines
17 Oct - 26 Oct	Icelandair
11 Oct - 21 Oct	Spirit Airlines
04 Oct - 18 Oct	Austrian Airlines

Also check the deals for one-way flights from Chicago to Istanbul 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 Chicago to Istanbul in October from 521€

Return flights