BOS to SEA from $303 in economy

UAUnited Airlines

Round Trip•Economy

BOS

Logan International Airport

Boston, United States

SEA

Seattle–Tacoma International Airport

Seattle / Tacoma, United States

$417 USD

-27%$303 USD

Verified 2 days ago

December 2026

Today

Mon

Tue

Wed

Thu

Fri

Sat

Sun

30$664 1$523 2$389 3$421 4$354 5$354 6$356 7$347 8$347 9$352 10$354 11$349 12$347 13$349 14$349 15$364 16$480 17$539 18$555 19$465 20$456 21$546 22$574 23$574 24$494 25$376 26$686 27$945 28$644 29$548 30$490 31$460 1$442 2$547 3$514

Limited Availability

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

Monday, December 7th, 2026

8 round-trip options

Returning

Sat, Dec 12, 2026•5 Day Trip

$356 USD

Google Flights

Returning

Sun, Dec 13, 2026•6 Day Trip

$356 USD

Google Flights

Returning

Mon, Dec 14, 2026•7 Day Trip

$356 USD

Google Flights

Returning

Tue, Dec 15, 2026•8 Day Trip

$354 USD

Google Flights

Returning

Fri, Dec 18, 2026•11 Day Trip

$436 USD

Google Flights

Returning

Sat, Dec 19, 2026•12 Day Trip

$347 USD

Google Flights

Returning

Sun, Dec 20, 2026•13 Day Trip

$382 USD

Google Flights

Returning

Mon, Dec 21, 2026•14 Day Trip

$361 USD

Google Flights

Boston (BOS) to Seattle / Tacoma (SEA) flight deal in economy from $303

Logan International Airport

Seattle–Tacoma International Airport

December 2026

Monday, December 7th, 2026