AirHint found the following cheapest return flights from Chicago (ORD) to Athens (ATH) in September 2025 (see full year).

Return flights

29 Sep - 06 Oct	Air Canada
03 Sep - 17 Sep	Turkish Airlines
29 Sep - 20 Oct	Turkish Airlines
06 Sep - 11 Sep	Turkish Airlines
01 Sep - 16 Sep	United
23 Sep - 03 Oct	SWISS
09 Sep - 23 Sep	SWISS
07 Sep - 19 Sep	United
02 Sep - 09 Sep	SWISS
14 Sep - 16 Sep	Frontier Airlines
24 Sep - 01 Oct	SWISS
08 Sep - 15 Sep	Turkish Airlines
21 Sep - 03 Oct	Lufthansa
16 Sep - 24 Sep	SWISS
09 Sep - 22 Sep	Austrian Airlines
29 Sep - 19 Oct	Turkish Airlines
30 Sep - 19 Oct	Turkish Airlines
30 Sep - 07 Oct	Turkish Airlines
24 Sep - 06 Oct	British Airways
29 Sep - 05 Oct	British Airways

Also check the deals for one-way flights from Chicago to Athens 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 Chicago to Athens in September from 460€

Return flights