AirHint found the following cheapest return flights from Detroit (DTW) to Porto (OPO) in July 2025 (see full year).

Return flights

20 Jul - 25 Jul	Spirit Airlines
07 Jul - 11 Jul	Spirit Airlines
06 Jul - 11 Jul	Spirit Airlines
05 Jul - 11 Jul	Spirit Airlines
06 Jul - 22 Jul	Spirit Airlines
05 Jul - 10 Jul	Spirit Airlines
03 Jul - 06 Jul	Spirit Airlines
27 Jul - 02 Aug	Spirit Airlines

Also check the deals for one-way flights from Detroit to Porto in July.

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 Detroit to Porto in July from $860

Return flights