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

Return flights

14 Sep - 20 Sep	Frontier Airlines
14 Sep - 21 Sep	United
09 Sep - 16 Sep	United
30 Sep - 07 Oct	United
03 Sep - 10 Sep	United
16 Sep - 23 Sep	United
23 Sep - 30 Sep	United
24 Sep - 01 Oct	United
17 Sep - 24 Sep	United
04 Sep - 11 Sep	United
12 Sep - 19 Sep	United
05 Sep - 12 Sep	United
25 Sep - 01 Oct	Scandinavian Airlines
26 Sep - 03 Oct	United
28 Sep - 05 Oct	United
15 Sep - 11 Oct	Air Canada
25 Sep - 02 Oct	United
29 Sep - 06 Oct	United
27 Sep - 04 Oct	United

Also check the deals for one-way flights from St. Louis to Amsterdam 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 Amsterdam in September from 651€

Return flights