Porto (OPO) to Washington (IAD) flight deal in economy from $676

Sunday, September 20th, 2026

4 round-trip options

Returning
Sat, Sep 26, 20266 Day Trip
$681 USD
Returning
Mon, Sep 28, 20268 Day Trip
$684 USD
Returning
Thu, Oct 1, 202611 Day Trip
$685 USD
Returning
Sat, Oct 3, 202613 Day Trip
$681 USD