AirHint found the following cheapest return flights from St. Louis (STL) to Rome (FCO) in September 2025 (see full year).

Return flights

16 Sep - 23 Sep	Air Canada
16 Sep - 16 Oct	Air France
09 Sep - 16 Sep	United
30 Sep - 07 Oct	United
15 Sep - 22 Sep	United
02 Sep - 09 Sep	United
23 Sep - 12 Oct	Air Canada
04 Sep - 11 Sep	United
06 Sep - 13 Sep	United
24 Sep - 01 Oct	United
18 Sep - 25 Sep	United
21 Sep - 28 Sep	United
27 Sep - 04 Oct	United
12 Sep - 19 Sep	United
19 Sep - 01 Oct	United

Also check the deals for one-way flights from St. Louis to Rome 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 St. Louis to Rome in September from $553

Return flights