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

Return flights

23 Sep - 02 Oct	British Airways
29 Sep - 07 Oct	Iberia
30 Sep - 07 Oct	Iberia
22 Sep - 01 Oct	Delta
16 Sep - 23 Sep	Air Canada
14 Sep - 25 Sep	British Airways
15 Sep - 09 Oct	British Airways
24 Sep - 01 Oct	Delta
26 Sep - 03 Oct	Iberia
29 Sep - 06 Oct	Air Canada
22 Sep - 03 Oct	Iberia
21 Sep - 20 Oct	British Airways
20 Sep - 30 Sep	British Airways
23 Sep - 29 Sep	Air Canada
09 Sep - 30 Sep	Air Canada
20 Sep - 29 Sep	jetBlue
17 Sep - 21 Sep	Delta
17 Sep - 22 Sep	Iberia
26 Sep - 29 Sep	Iberia
24 Sep - 29 Sep	Iberia

Also check the deals for one-way flights from Washington to Madrid 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.

Book a cheap hotel in Madrid

Cheap car rent in Madrid

Cheapest return flights from Washington to Madrid in September from $437

Return flights