SEA - BOS

$212 Find Cheap Flights from Seattle to Boston - Compare and Save

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Everything you should know

Cheapest round-trip
$299
Typical prices: $378-$589
Alaska Airlines
Fri 12/7Tue 12/11
SEA - BOS • 1 stop
Cheapest non-stop
$362
Typical prices: $380-$589
Alaska Airlines
Fri 12/7Sat 12/8
SEA - BOS • Non-stop
Advice from real travelers
Delta offers free Wi-Fi for SkyMiles members on domestic Seattle-Boston flights.
Alaska adds a 20-minute bag guarantee; download its app for onboard entertainment.
Expert advice
+1
Expert advice
+1
Nonstop flights
You can fly direct with Delta and Alaska Airlines. Average duration is 5h 22m
Direct flights
+1
Direct flights
+1
Avoid delays
Most punctual • 88% on-time
Best time • Fewest delays
Insights
Insights
When to book
in advance
Our data shows that travelers who book at least 25 weeks in advance save around 47% compared to booking last minute.
Insights
Insights
When to travel
Cheapest • 17% price drop
Most popular
Good to know
+1
Good to know
+1
Top layover airports
Cheapest • Avg $279 (round-trip)
Shortest trip • 8h 17m (one-way)
Insights
Insights
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We hope you love your trip to Boston!
Flight Deals
Booking Insights
Expert advice
Flight Deals

Cheap Flights from Seattle to Boston (SEA-BOS)

 
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Seattle to Boston

Mon, Dec 7 - Fri, Dec 11
Alaska Airlines Logo
9:12 am - 5:09 pmSEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
28h 57m1 stop San Diego
Alaska Airlines Logo
6:13 pm - 9:32 amBOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
18h 19m1 stop San Diego
$299Alaska Airlines
Mon, Dec 7 - Sat, Dec 12
Alaska Airlines Logo
11:50 am - 5:09 pmSEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
26h 19m2 stops San Francisco San Diego
Alaska Airlines Logo
6:13 pm - 9:32 amBOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
18h 19m1 stop San Diego
$318Alaska Airlines
Tue, Dec 8 - Mon, Dec 14
Delta Logo
3:45 pm - 12:02 amSEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
5h 17mnonstop
Delta Logo
7:50 am - 11:21 amBOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
6h 31mnonstop
$367Delta
Fri, Dec 11 - Mon, Dec 14
Delta Logo
10:52 pm - 7:19 amSEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
5h 27mnonstop
Delta Logo
7:26 pm - 10:55 pmBOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
6h 29mnonstop
$367Delta
Thu, Dec 3 - Wed, Dec 9
Multiple Airlines Logo
1:32 pm - 7:21 amSEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
14h 49m1 stop Los Angeles
Multiple Airlines Logo
5:10 pm - 9:32 amBOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
19h 22m1 stop San Diego
$379Multiple Airlines
Sun, Dec 13 - Wed, Dec 16
American Airlines Logo
6:20 am - 5:03 pmSEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
7h 43m1 stop Chicago O'Hare Intl
American Airlines Logo
1:27 pm - 8:31 pmBOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
10h 04m1 stop Chicago O'Hare Intl
$387American Airlines
Thu, Dec 10 - Sun, Dec 13
American Airlines Logo
10:51 am - 11:32 pmSEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
9h 41m1 stop Chicago O'Hare Intl
American Airlines Logo
7:15 am - 2:36 pmBOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
10h 21m1 stop Chicago O'Hare Intl
$387American Airlines
Thu, Dec 3 - Wed, Dec 9
Frontier Logo
1:32 pm - 5:32 amSEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
13h 00m1 stop Los Angeles
Frontier Logo
7:30 am - 3:43 pmBOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
11h 13m1 stop Denver Intl
$387Frontier
Fri, Dec 4 - Mon, Dec 7
Southwest Logo
1:35 pm - 11:45 pmSEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
7h 10m1 stop Denver Intl
Southwest Logo
1:10 pm - 10:50 pmBOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
12h 40m2 stops Lambert-St Louis Denver Intl
$392Southwest
Fri, Dec 11 - Mon, Dec 14
Southwest Logo
5:30 am - 4:10 pmSEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
7h 40m1 stop Chicago Midway
Southwest Logo
8:25 am - 9:40 pmBOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
16h 15m2 stops San Diego Oakland
$398Southwest
Booking Insights

Price, demand and travel trends for Seattle to Boston flights

Use KAYAK data on prices, travel dates, airlines and seasonal trends to compare options and book flights with more confidence.

How much is a round-trip flight from Seattle to Boston?

Round-trip flights from Seattle to Boston typically range from $378 to $589. The lowest price found in the past 5 days was $299, on Alaska Airlines.

What's the cheapest day of the week to fly from Seattle to Boston?

Based on deals KAYAK users found in the last 12 months, Tuesday is the cheapest day of the week to fly from Seattle to Boston. It’s 10% cheaper than the average day, while Monday is the most expensive, with prices 13% higher.

What’s the cheapest month to fly from Seattle to Boston?

•March is the cheapest month to fly from Seattle to Boston at $390 round-trip.
•November ($608) and December ($570) are the most expensive months.
•The price difference between flying in the cheapest and most expensive months is 55% on average.
This is based on KAYAK aggregated and averaged internal data over the past 12 months.

When are flights from Seattle to Boston the cheapest?

Flights from Seattle to Boston are cheapest 25 weeks before departure. Booking in this window typically costs about 47% less than the average last-minute fare (within 2 weeks of the flight), based on KAYAK data.

Expert advice

Expert advice for your flight from Seattle to Boston

 
KAYAK teamed up with top travel experts to share the best tips for your journey.
Our travel experts
Stefanie Waldek

Stefanie Waldek

Expert on Delta

Stefanie Waldek is a freelance space, travel, and design writer based in Saratoga Springs, NY. Her words have appeared in Space.com, Travel + Leisure, Condé Nast Traveler, Architectural Digest, and House Beautiful, among other publications. An expert in aviation and expedition cruising, Stefanie is frequently up in the air or on the sea, likely en route to Antarctica or the Arctic.

Harriet Baskas

Harriet Baskas

Expert on Alaska Airlines and SEA

Harriet is an award-winning journalist who is happiest in an airport or an unusual museum. Her stories about airports, air travel, and the business of travel have appeared on NBC News, CNBC, USA TODAY, The Points Guy and other outlets. She is the creator of the StuckatTheAirport.com blog and the author of nine books. When not out on the road or exploring the latest airport amenities, she’s home in Seattle getting ready for the next adventure.

Blane Bachelor

Blane Bachelor

Expert on BOS

Blane Bachelor is a journalist and editor specializing in travel and aviation who writes regularly for top global outlets. Born and raised in Florida, Blane has worked and lived in four countries, including the Netherlands, where she’s currently based with her family. Her favorite way to get to know a new destination is by running or riding a bike around town – or hearing a spooky ghost story about local history. She will always choose the window seat.

Key details for Seattle to Boston flights

Low season

February

Cheapest flight

$212
Beat the crowds with an average 48% drop in travelers.
The most popular month to fly with an average 48% increase in travelers.
One-way flight from Seattle to Boston

When to book flights from Seattle to Boston

Are your dates flexible? Find out the best times to travel from Seattle to Boston based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price

Flights from Seattle to Boston: the best tips from KAYAK users' own experiences

Insights shared by verified travelers who flew the route from Seattle to Boston 
MichelleFlew with Alaska Airlines-Oct 2026
It’s a long flight. Wear a mask is you want to avoid catching something someone on flight may have.
rsmrostovFlew with Alaska Airlines-Jan 2026
If you have a small personal bag and a personal item you will be hustled to consolidate snacks on the flight of very poor so bring your own food and if you have an Android phone you likely will have issues connecting to Wi-Fi on the plane especially if the connection was dropped in the middle of watching a movie and then you attempt to reinstate it sometimes you have to clear browsing history and cookies becomes painful
Verified travelerFlew with Alaska Airlines-Jul 2024
Generally Alaska Airlines have very friendly and helpful people in my experience. They don’t have TVs in all planes so make sure to download their app if you want entertainment on the plane.

Your Seattle to Boston flight questions, answered

Find helpful answers about this route, including flight times, airports, airlines and booking tips.

  • What are the earliest and latest flights from Seattle to Boston?

    These are the earliest and latest flight times currently scheduled from Seattle to Boston:

    • Earliest: departs at 7:15 am and lands at 12:37 pm
    • Latest: departs at 11:22 pm and lands at 4:44 am.

    The flight takes about 5h 22m.

  • What cabin classes can I book on flights from Seattle to Boston?

    Four cabin classes are available on flights from Seattle to Boston:

    • Economy Class
    • Premium Economy Class
    • Business Class
    • First Class

    Prices vary by airline.

  • How long is a flight from Seattle to Boston?

    A nonstop flight from Seattle to Boston takes about 5h 22m, covering 2,487 miles.

  • Do I need a passport to fly from Seattle to Boston?

    No, a passport is not required for this domestic route, but you will need a real ID-compliant driver's license, a state ID or another TSA-accepted form of identification.

  • How much should I expect to pay for a Seattle to Boston flight?

    Round-trip flights from Seattle to Boston range from $378 to $589, with an average of $470 over the past 12 months. Anything below $378 counts as a good deal.

  • How expensive are last-minute Seattle to Boston flights?

    Last-minute fares on this route (booked within two weeks of departure) run 37% above the $470 route average. Book 25 weeks before departure for the lowest fares.

  • How much can I save by taking a layover when flying from Seattle to Boston?

    On this route, layover flights are cheaper than nonstop options on average. Layover fares average $279 round-trip via Baltimore/Washington (BWI), compared to $472 for nonstop.

  • How does on-time performance compare across airlines flying from Seattle to Boston?

    Delta is slightly above the route average for timely arrivals, while Alaska Airlines has a lower on-time arrival rate. On-time arrival rates on Seattle to Boston flights are:

    • Delta: 88% on time
    • Alaska Airlines: 85% on time
    • JetBlue: 58% on time

    Overall, flights on this route are punctual 83% of the time on average.

  • What is the standard checked-bag allowance on flights from Seattle to Boston?

    There is no standard. Checked-bag policies vary by airline on this route. Most carriers charge $35–$100 for the first checked bag in economy. Premium fares and elite-status bookings typically include a free checked bag.

  • Which aircraft model is used most often on flights from Seattle to Boston?

    The Airbus A321neo family is used most often on this route, operated mainly by Delta. Other aircraft seen on the route include Boeing 737 variants.

  • How are flight departures from Seattle to Boston spread across the day?

    Morning is most often the busiest departure period on Seattle to Boston flights, with 40% of flights leaving in that window. Night departures account for 40%, and afternoon flights for 20%.

  • Have flight prices from Seattle to Boston changed much recently?

    Yes. Based on fares seen in the past 5 days, round-trip prices on this route showed a wide range, from about $299 to $1,699. That means the highest observed fare was about 6x higher than the lowest one.

  • Which airlines offer Wi-Fi on Seattle to Boston flights?

    Three airlines typically offer in-flight Wi-Fi on Seattle to Boston flights:

    • Delta
    • Alaska Airlines
    • JetBlue

    Pricing varies by airline and fare class. Some plans are included with the ticket or loyalty program; others are paid add-ons priced by flight length.

  • How are flight prices from Seattle to Boston looking right now?

    One-way fares from Seattle to Boston are currently lower than usual. Average one-way flight prices are about $228, which is 23% below the typical average for this route.

  • What car rental options are available at Boston Logan Intl Airport (BOS)?

    Boston Logan Intl Airport (BOS) hosts 5 major car rental companies, with daily rates averaging $79 for economy cars. Top options include:

    • Dollar
    • Hertz
    • Budget
    • Thrifty
    • Sixt

  • Which airports can I use when flying from Seattle to Boston?

    Flights from Seattle to Boston usually depart from Seattle/Tacoma Intl (SEA) and arrive at Boston Logan Intl (BOS).

  • What time of day has the fewest delays on flights from Seattle to Boston?

    Night flights have the fewest delays on this route, while morning departures tend to have the most.

  • At what point is a flight considered delayed from Seattle to Boston?

    A flight is considered delayed when it departs 15 minutes or more after its scheduled time. This is the standard used by the US Department of Transportation and most airline industry reporting. On the Seattle to Boston route, 17% of flights were delayed in the past 3 months, with delays averaging 2h 59m.

  • Which airports do connecting flights from Seattle to Boston pass through?

    One-stop flights from Seattle to Boston most commonly connect through:

    • Minneapolis St Paul (MSP) - 40% of one-stop connections
    • Chicago O'Hare Intl (ORD) - 23% of one-stop connections
    • Philadelphia (PHL) - 13% of one-stop connections
    • Chicago Midway (MDW) - 9% of one-stop connections

  • Can I save money by using flexible dates for flights from Seattle to Boston?

    Yes. Flexible dates can save you up to 20% on flights from Seattle to Boston. Tuesday is the cheapest departure day at $427 round-trip on average, while Monday is the most expensive at $532, a difference of $105.

    KAYAK's flexible dates feature shows options up to 3 days before and after your selected dates, making it easier to compare nearby fares.

  • What airlines fly from Seattle to Boston?

    Only Delta and Alaska Airlines currently operate flights between Seattle and Boston on a regular basis.

  • How much time can I save by choosing a different layover airport from Seattle to Boston?

    Flying via Denver Intl (DEN) gives the shortest average 1-stop total travel time at 8h 17m, compared with 8h 22m via Chicago Midway (MDW) and 8h 23m via Salt Lake City (SLC).

  • What is the time difference between Seattle and Boston?

    Boston is 3 hours ahead of Seattle (Eastern Time vs Pacific Time). Plan for the time shift when scheduling connections or first-day activities.

  • What popular places can I visit in Boston?

    Some of the most popular sights in Boston are TD Garden, Fenway Park and Boston Common. These are among the most viewed places in Boston on KAYAK.

  • Which airlines offer free seat selection on Seattle to Boston flights?

    The following airlines offer free seat selection on this route:

    • Delta
    • Alaska Airlines
    • JetBlue
    • American Airlines

    Availability depends on fare class.

  • Which airlines offer extra legroom on Seattle to Boston flights?

    Delta, Alaska Airlines and JetBlue offer extra legroom on this route. Availability can vary by aircraft type and fare class.

  • Which airlines include bags at no extra cost on Seattle to Boston flights?

    Here are some options for this route, based on selected ticket types and cabin classes:

    • Delta: a cabin bag and a checked bag in Economy Class
    • Alaska Airlines: a cabin bag and a checked bag in Economy Class
    • American Airlines: a cabin bag and a checked bag in Business Class

    Bag allowance can vary by ticket type, cabin class, route and airline, so always check the fare details before booking.

  • Where can I find bus services at Logan airport?

    BOS provides free bus services around the airport. The buses have low floors, which make boarding and luggage loading easier. They also have a wheelchair lift for travelers with disabilities.

  • How can I connect from downtown Seattle to Seattle-Tacoma International Airport?

    Sound Transit’s Link Light Rail connects downtown Seattle with SEA in about 40 minutes. Taxis, rideshares and buses are also available and buses generally cost less.

  • Where can I rent a car at Boston Logan International Airport?

    Boston Logan International Airport operates its own off-site car rental center at 15 Transportation Way. The blue- and white-colored buses depart every 5-6min. Some agencies offer shuttle and pickup services at BOS.

  • How can I move between terminals at Boston Logan International Airport?

    Boston Logan International Airport (BOS) has four terminals. Terminal E is the primary international terminal, although international departures may leave from any of the four terminals and most international arrivals come through Terminal E. Walkways connect all terminals, which makes it possible to walk between them without heavy luggage. Regular shuttles also run between terminals every 5 to 15 minutes.

  • Are pets allowed on flights between Seattle and Boston?

    Yes, SEA and BOS both have pre- and post-security pet-relief areas for cats and dogs. Most flights on this route also allow cats and dogs in the cabin, though requirements such as health certificates and age vary by carrier.

  • What assistance can I get at the Seattle airport?

    SEA provides facilities and staff support to help travelers move around the airport. Wheelchair services are available at no cost for travelers with disabilities with advance reservation.

  • Are there accessible services for travelers with disabilities on flights from SEA to BOS?

    Yes, advance notice is generally not required to arrange a wheelchair or other guided assistance before departure on flights from SEA to BOS. At SEA, complimentary wheelchair assistance is available from baggage claim, the parking garage and the Link light-rail station to check-in. After security, wheelchair service is provided by the airline. At BOS, airline personnel are required to provide requested mobility assistance through the terminals. Restrooms at both SEA and BOS are accessible.

Your guide to booking Seattle to Boston flights

Get tips on when to book, when to fly and what to know before your trip.
  • If your dates are flexible, aim for a Tuesday departure and avoid flying on Monday. On this route, Tuesday flights average $427, about $105 less than Monday fares (20% savings) based on the last 12 months.
  • For the best chance at a low fare, aim to book around 25 weeks before you fly. On this route, that window historically saves about 47% versus last-minute pricing (KAYAK booking data, last 12 months).
  • If you can choose when to travel, plan your Seattle to Boston trip for March. Fares historically average $390 round-trip in that month - typically $218 less than the most expensive month, which is November (based on the last 12 months).
  • For the best chance of arriving on time, fly with Delta. Over the past three months, 88% of Delta flights from Seattle to Boston arrived on time, slightly above the route average of 83%. When flights on this route arrive late, they're delayed by an average of 2h 59m, so choosing an airline with strong on-time performance can make a difference if you're on a tight schedule.
  • If you have the time, taking a 1-stop flight through Baltimore/Washington Airport (BWI) can be cheaper than flying direct. The cheapest layover option averages $279 round-trip on this route - about $193 less than direct flights (based on the last 12 months).
  • If you're arriving late at night and need somewhere to stay, check out these hotels close to Boston Logan Intl Airport.

    • Hilton Boston Logan Airport
    • Hilton Garden Inn Boston Logan Airport
    • Embassy Suites by Hilton Boston at Logan Airport
  • If you're traveling with young kids, you can use the nursing rooms in several areas of the airport. There's one in the Children Play Area at Concourse A, another in Concourse D next to D24 and one in the International Arrivals Facility mezzanine near the family restrooms.
  • If you arrive at SEA early before your flight to BOS, head to The Lookout at C to relax. It's on the third level of Concourse C above Gate C3 and offers unobstructed airfield views from a glass-enclosed deck.
  • If you want a drink, a snack or complimentary Wi-Fi after landing at Logan International Airport, head to the United Club in Terminal B. A one-time pass is available for one person.
  • Driving to Seattle airport? You can choose Reserved Parking or Drive-up General Parking.
  • At Seattle-Tacoma International Airport, use the free Wi-Fi, then stop by a Club at SEA lounge for complimentary snacks, beverages and bar service. You'll find Club at SEA near Gate A12 in the A Concourse and on the mezzanine level above Gate S10 in the S Concourse.

Prefer to fly direct from Seattle to Boston?

 
Find which airlines fly direct from Seattle/Tacoma Intl Airport to Boston Logan Intl Airport, which days they fly and book direct flights.

Direct departures

Seattle/Tacoma Intl to Boston Logan Intl

Monday

Alaska Airlines,Delta

Alaska Airlines,Delta

Tuesday

Alaska Airlines,Delta

Alaska Airlines,Delta

Wednesday

Alaska Airlines,Delta

Alaska Airlines,Delta

Thursday

Alaska Airlines,Delta

Alaska Airlines,Delta

Friday

Alaska Airlines,Delta

Alaska Airlines,Delta

Saturday

Alaska Airlines,Delta

Alaska Airlines,Delta

Sunday

Alaska Airlines,Delta

Alaska Airlines,Delta

See more direct flights

Direct returns

Boston Logan Intl to Seattle/Tacoma Intl

Monday

Alaska Airlines,Delta

Alaska Airlines,Delta

Tuesday

Alaska Airlines,Delta

Alaska Airlines,Delta

Wednesday

Alaska Airlines,Delta

Alaska Airlines,Delta

Thursday

Alaska Airlines,Delta

Alaska Airlines,Delta

Friday

Alaska Airlines,Delta

Alaska Airlines,Delta

Saturday

Alaska Airlines,Delta

Alaska Airlines,Delta

Sunday

Alaska Airlines,Delta

Alaska Airlines,Delta

See more direct flights

More options for your flight from Seattle to Boston

Complete your trip to Boston with a hotel stay or car rental