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

Return flights

30 Sep - 15 Oct	American Airlines
29 Sep - 15 Oct	American Airlines
29 Sep - 08 Oct	British Airways
23 Sep - 08 Oct	British Airways
29 Sep - 07 Oct	United
30 Sep - 07 Oct	United
23 Sep - 07 Oct	United
24 Sep - 01 Oct	United
23 Sep - 11 Oct	British Airways
22 Sep - 29 Sep	Iberia
24 Sep - 05 Oct	British Airways
14 Sep - 23 Sep	Iberia	direct
20 Sep - 30 Sep	United
21 Sep - 30 Sep	KLM
03 Sep - 12 Sep	United
16 Sep - 23 Sep	United
22 Sep - 30 Sep	KLM
10 Sep - 17 Sep	United
16 Sep - 24 Sep	United
20 Sep - 27 Sep	United

Also check the deals for one-way flights from San Juan 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.

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Cheapest return flights from San Juan to Madrid in September from 388€

Return flights