AirHint found the following cheapest return flights from Washington (DCA) to Brussels (BRU) in September 2025 (see full year).

Return flights

16 Sep - 23 Sep	Scandinavian Airlines
14 Sep - 23 Sep	jetBlue
16 Sep - 11 Oct	Scandinavian Airlines
24 Sep - 01 Oct	Icelandair
26 Sep - 30 Sep	Air Canada
10 Sep - 15 Sep	Icelandair
13 Sep - 16 Oct	Scandinavian Airlines
11 Sep - 18 Sep	Air Canada
22 Sep - 08 Oct	Icelandair
19 Sep - 30 Sep	Air Canada
12 Sep - 16 Oct	Scandinavian Airlines
11 Sep - 04 Oct	Icelandair
19 Sep - 24 Sep	Icelandair

Also check the deals for one-way flights from Washington to Brussels 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 Washington to Brussels in September from $537

Return flights