Porto (OPO) to Washington (IAD) flight deal in economy from $641

Monday, August 17th, 2026

5 round-trip options

Returning
Sun, Aug 23, 20266 Day Trip
$1,048 USD
Returning
Tue, Aug 25, 20268 Day Trip
$1,012 USD
Returning
Wed, Aug 26, 20269 Day Trip
$1,020 USD
Returning
Fri, Aug 28, 202611 Day Trip
$1,012 USD
Returning
Mon, Aug 31, 202614 Day Trip
$1,012 USD