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

Return flights

04 Sep - 14 Sep	Spirit Airlines
01 Sep - 22 Sep	Frontier Airlines
25 Sep - 29 Sep	Frontier Airlines
10 Sep - 15 Sep	Spirit Airlines
28 Sep - 05 Oct	Spirit Airlines
06 Sep - 17 Sep	Frontier Airlines
11 Sep - 18 Sep	United	direct
07 Sep - 21 Sep	United	direct
08 Sep - 22 Sep	United	direct
09 Sep - 23 Sep	United	direct
10 Sep - 24 Sep	United	direct
28 Sep - 12 Oct	United	direct
17 Sep - 01 Oct	United	direct
18 Sep - 02 Oct	United	direct
29 Sep - 13 Oct	United	direct
30 Sep - 14 Oct	United
22 Sep - 06 Oct	United	direct
21 Sep - 05 Oct	United
23 Sep - 07 Oct	United
26 Sep - 10 Oct	United

Also check the deals for one-way flights from Chicago to Sao Paulo 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 Sao Paulo in September from 504€

Return flights