AirHint found the following cheapest one-way flights from Athens (ATH) to Istanbul (IST) in September 2025 (see full year).

One-Way flights

15 Sep	SKY express	direct
18 Sep	SKY express	direct
25 Sep	SKY express	direct
30 Sep	SKY express	direct
16 Sep	SKY express	direct
11 Sep	SKY express	direct
10 Sep	SKY express	direct
27 Sep	SKY express	direct
20 Sep	SKY express	direct
12 Sep	SKY express	direct

Also check the deals for return flights from Athens to Istanbul 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.

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Cheapest one-way flights from Athens to Istanbul in September from $52

One-Way flights