AirHint found the following cheapest return flights from Chicago (MDW) to Madrid (MAD) in October 2025 (see full year).

Return flights

06 Oct - 14 Oct	KLM
15 Oct - 23 Oct	Delta
01 Oct - 08 Oct	Delta
31 Oct - 06 Nov	Delta
01 Oct - 06 Oct	Delta
08 Oct - 14 Oct	Delta
22 Oct - 29 Oct	Delta
08 Oct - 12 Oct	Delta
10 Oct - 15 Oct	Frontier Airlines
17 Oct - 20 Oct	Delta
14 Oct - 18 Oct	Frontier Airlines
06 Oct - 01 Nov	Air France
31 Oct - 07 Nov	Virgin Atlantic

Also check the deals for one-way flights from Chicago to Madrid in October.

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 Chicago to Madrid in October from $463

Return flights