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

Return flights

19 Sep - 21 Sep	Icelandair
30 Sep - 07 Oct	Icelandair
30 Sep - 14 Oct	Icelandair
03 Sep - 10 Sep	Icelandair
12 Sep - 19 Sep	Icelandair
18 Sep - 25 Sep	Icelandair
24 Sep - 08 Oct	Icelandair
24 Sep - 01 Oct	Icelandair
09 Sep - 16 Sep	Icelandair
11 Sep - 15 Sep	Icelandair
21 Sep - 28 Sep	Icelandair
15 Sep - 22 Sep	Icelandair
06 Sep - 13 Sep	Icelandair
15 Sep - 22 Sep	Scandinavian Airlines	direct
30 Sep - 07 Oct	Scandinavian Airlines	direct
21 Sep - 06 Oct	Icelandair
25 Sep - 06 Oct	Icelandair
27 Sep - 04 Oct	Scandinavian Airlines	direct
28 Sep - 01 Oct	Delta
29 Sep - 02 Oct	Delta

Also check the deals for one-way flights from Chicago to Copenhagen 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 Copenhagen in September from 373€

Return flights