AirHint found the following cheapest return flights from Istanbul (IST) to Frankfurt (FRA) in September 2025 (see full year).

Return flights

22 Sep - 26 Sep	AJet	direct
25 Sep - 25 Sep	AJet	direct
30 Sep - 08 Oct	AJet	direct
29 Sep - 07 Oct	AJet	direct
30 Sep - 15 Oct	AJet	direct
29 Sep - 06 Oct	AJet
16 Sep - 23 Sep	Pegasus Airlines
25 Sep - 30 Sep	AJet
25 Sep - 28 Sep	AJet	direct
22 Sep - 29 Sep	AJet
25 Sep - 30 Sep	AJet	direct
11 Sep - 13 Sep	Pegasus Airlines
19 Sep - 26 Sep	AJet	direct
19 Sep - 22 Sep	AJet	direct
18 Sep - 07 Oct	AJet	direct
25 Sep - 04 Oct	AJet
25 Sep - 04 Oct	Lufthansa	direct
27 Sep - 03 Oct	Pegasus Airlines
26 Sep - 05 Oct	AJet
24 Sep - 01 Oct	AJet

Also check the deals for one-way flights from Istanbul to Frankfurt 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 return flights from Istanbul to Frankfurt in September from 123€

Return flights