$134 Cheap United flights Seattle (SEA) to Boston (BOS)

Finding cheap one-way United Airlines flights from SEA to BOS from $134 on Expedia is a breeze — just filter by “Price (lowest to highest).” Or check out our affordable return fares from $257 for your next exciting adventure.**These prices were available on Expedia within the past 7 days, for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.

Browse for return or one-way flights to Boston in January or February. You could find an affordable fare with United Airlines during these off-season months.

For cheap United Airlines fares from Seattle - Tacoma Intl. Airport (SEA) to Logan Intl. Airport (BOS), start searching one to three months before your intended departure. Securing domestic flights 34 to 86 days in advance could save you 25% compared to booking just 6 to 12 days ahead. The day you book can also affect the cost. Sunday is generally the cheapest, while Monday is often the most expensive for domestic flights. You can save 6% on average by booking your trip on a Sunday.**Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC’s global airline sales database.

Simply enter your dates, click search and use the “Nonstop” filter on Expedia to browse any direct flights from SEA to BOS with United Airlines or another airline.

Browse United Airlines’s earliest flights from SEA to BOS by selecting our “Early Morning” and “Morning” filters. Not only will you arrive sooner, early departures also have a 20% less chance of being canceled.**Most reliable time of the day recommendation is based on January through August 2024 flight status data sourced from OAG’s global flight data platform.

Logan Intl. Airport (BOS) is the main Boston hub for United Airlines flights from Seattle - Tacoma Intl. Airport (SEA).

Fly from SEA to BOS with United Airlines and you’ll enjoy a host of benefits including a rewarding loyalty program. When booking through Expedia as a United Mileage Plus and One Key™ member, you could also earn OneKeyCash™* to use on select future travel purchases.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.

Depending on the ticket type you purchased, a fee may apply if you cancel or reschedule your flight more than 24 hours after it’s been confirmed. To secure tickets with more flexibility, select our “Changes included” and “No cancel fee” boxes while looking for flights. For more information on canceling or changing your reservation, visit “Trips,” select your flight and tick “Manage Booking.”