SEA to BOS from $303 in economy – flightdeals.net

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United Airlines

UAUnited Airlines

Round Trip•Economy

Seattle–Tacoma International Airport

Seattle / Tacoma, United States

Logan International Airport

Boston, United States

$421 USD

-28%$303 USD

Verified 1 day ago

December 2026

Mon

Tue

Wed

Thu

Fri

Sat

Sun

30$438 1$359 2$352 3$354 4$354 5$352 6$361 7$359 8$354 9$354 10$360 11$477 12$472 13$463 14$378 15$461 16$582 17$641 18$534 19$499 20$382 21$449 22$588 23$649 24$361 25$347 26$438 27$361 28$361 29$399 30$357 31$359 1$359 2$401 3$394

Limited Availability

10% of dates checked are available within 10% of the lowest price

Thursday, December 10th, 2026

3 round-trip options

Returning

Tue, Dec 15, 2026•5 Day Trip

$360 USD

Returning

Thu, Dec 17, 2026•7 Day Trip

$546 USD

Returning

Mon, Dec 21, 2026•11 Day Trip

$515 USD