Seattle / Tacoma (SEA) to Bilbao (BIO) flight deal in economy from $612

Monday, December 21st, 2026

10 round-trip options

Returning
Sat, Dec 26, 20265 Day Trip
$1,534 USD
Returning
Sun, Dec 27, 20266 Day Trip
$1,595 USD
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Mon, Dec 28, 20267 Day Trip
$1,536 USD
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Tue, Dec 29, 20268 Day Trip
$1,704 USD
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Wed, Dec 30, 20269 Day Trip
$1,715 USD
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Thu, Dec 31, 202610 Day Trip
$1,574 USD
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Fri, Jan 1, 202711 Day Trip
$1,891 USD
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Sat, Jan 2, 202712 Day Trip
$2,334 USD
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Sun, Jan 3, 202713 Day Trip
$2,584 USD
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Mon, Jan 4, 202714 Day Trip
$2,326 USD