SEA - BOS

C$ 292 Find Cheap Flights from Seattle to Boston – Compare and Save

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1 adult, Economy, 0 bags

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Everything you should know

Cheapest round-trip
C$ 443
Typical prices: C$ 518-C$ 813
Alaska Airlines
Sat 8/12Tue 11/12
SEA - BOS • 1 stop
Cheapest direct flights
C$ 646
Typical prices: C$ 520-C$ 812
Alaska Airlines
Fri 13/4Sat 14/4
SEA - BOS • Direct
Advice from real travellers
JetBlue adds free Wi-Fi for all; Delta limits free Wi-Fi to SkyMiles members.
Delta Comfort Plus and JetBlue Even More Space add legroom on this long flight.
Expert advice
+1
Expert advice
+1
Direct flights
You can fly direct with Delta and Alaska Airlines. Average duration is 5h 24m
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 travellers 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 C$ 390 (round-trip)
Shortest trip • 8h 21m (one-way)
Insights
Insights
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We hope you enjoy 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

Tue, 8 Dec - Fri, 11 Dec
Alaska Airlines Logo
5:51 p.m. - 5:09 p.m.SEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
20h 18m1 stop San Diego
Alaska Airlines Logo
6:13 p.m. - 9:32 a.m.BOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
18h 19m1 stop San Diego
C$ 443Alaska Airlines
Wed, 9 Dec - Sun, 13 Dec
Alaska Airlines Logo
9:12 a.m. - 5:08 p.m.SEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
28h 56m1 stop San Diego
Alaska Airlines Logo
6:13 p.m. - 9:32 a.m.BOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
18h 19m1 stop San Diego
C$ 443Alaska Airlines
Sat, 5 Dec - Fri, 11 Dec
Alaska Airlines Logo
3:00 p.m. - 5:08 p.m.SEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
23h 08m1 stop San Diego
Alaska Airlines Logo
6:13 p.m. - 9:32 a.m.BOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
18h 19m1 stop San Diego
C$ 443Alaska Airlines
Wed, 9 Dec - Sun, 13 Dec
Alaska Airlines Logo
12:18 p.m. - 5:08 p.m.SEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
25h 50m1 stop San Diego
Alaska Airlines Logo
6:13 p.m. - 9:32 a.m.BOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
18h 19m1 stop San Diego
C$ 443Alaska Airlines
Thu, 10 Dec - Sun, 13 Dec
Alaska Airlines Logo
7:05 a.m. - 5:08 p.m.SEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
31h 03m1 stop San Diego
Alaska Airlines Logo
6:13 p.m. - 9:32 a.m.BOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
18h 19m1 stop San Diego
C$ 443Alaska Airlines
Sat, 21 Nov - Fri, 4 Dec
Alaska Airlines Logo
8:58 p.m. - 5:24 a.m.SEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
29h 26m1 stop San Diego
Alaska Airlines Logo
6:13 p.m. - 7:18 p.m.BOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
28h 05m1 stop San Diego
C$ 443Alaska Airlines
Thu, 10 Dec - Mon, 14 Dec
Alaska Airlines Logo
7:05 a.m. - 5:08 p.m.SEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
31h 03m1 stop San Diego
Alaska Airlines Logo
6:13 p.m. - 7:18 p.m.BOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
28h 05m1 stop San Diego
C$ 443Alaska Airlines
Thu, 3 Dec - Mon, 7 Dec
Alaska Airlines Logo
7:05 a.m. - 5:08 p.m.SEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
31h 03m1 stop San Diego
Alaska Airlines Logo
6:13 p.m. - 9:57 p.m.BOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
30h 44m1 stop San Diego
C$ 443Alaska Airlines
Tue, 17 Nov - Sat, 21 Nov
United Airlines Logo
9:05 a.m. - 9:24 p.m.SEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
9h 19m1 stop San Francisco
United Airlines Logo
1:29 p.m. - 7:03 p.m.BOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
8h 34m1 stop Chicago O'Hare Intl
C$ 450United Airlines
Wed, 2 Dec - Sat, 5 Dec
United Airlines Logo
7:00 a.m. - 5:41 p.m.SEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
7h 41m1 stop Newark
United Airlines Logo
3:42 p.m. - 11:00 p.m.BOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
10h 18m1 stop Newark
C$ 457United Airlines
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 C$ 518 to C$ 813. The lowest price found in the past 5 days was C$ 443, 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 9% cheaper than the average day, while Sunday is the most expensive, with prices 12% higher.

What is the cheapest month to fly from Seattle to Boston?

•March is the cheapest month to fly from Seattle to Boston at C$ 540 round-trip.
•December (C$ 793) and August (C$ 670) are the most expensive months.
•The price difference between flying in the cheapest and most expensive months is 46% 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
Harriet Baskas

Harriet Baskas

Expert on JetBlue, 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.

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.

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

C$ 292
Beat the crowds with an average 48% drop in traveller numbers.
The most popular month to fly with an average 44% increase in traveller numbers.
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 travellers 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 available from Seattle to Boston:

    • Earliest: departs at 7:15 am and lands at 12:39 pm
    • Latest: departs at 11:59 pm and lands at 5:23 am.

    The flight takes about 5h 24m.

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

    Only Economy Class is available on flights from Seattle to Boston.

  • How long does a flight from Seattle to Boston take?

    A direct flight from Seattle to Boston takes 5h 24m, covering 6,441 km.

  • 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 another form of identification, such as a driver's licence.

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

    Round-trip flights from Seattle to Boston range from C$ 518 to C$ 813, with an average of C$ 647 over the past 12 months. Anything below C$ 518 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 38% above the C$ 647 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 direct options on average. Layover fares average C$ 390 round-trip via Baltimore/Washington (BWI), compared to C$ 650 for direct.

  • 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

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

  • 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 C$ 49–C$ 140 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 Airbus A321-100/200 variants.

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

    Morning is the busiest departure period on Seattle to Boston flights, with 40% leaving in that window. Night departures account for 40%, Afternoon flights for 20%, and Evening flights for 0%.

  • 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 C$ 443 to C$ 2,328. That means the highest observed fare was about 5x higher than the lowest one.

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

    Three airlines 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 C$ 302, which is 25% 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 C$ 108 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 on the route 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 three 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) – 45% of one-stop connections
    • Chicago O'Hare Intl (ORD) – 21% of one-stop connections
    • Philadelphia (PHL) – 10% of one-stop connections
    • Chicago Midway (MDW) – 10% 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 C$ 589 round-trip on average, while Sunday is the most expensive at C$ 727, a difference of C$ 138.

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

  • Which airlines fly from Seattle to Boston?

    2 airlines operate flights between Seattle and Boston. The airlines offering direct flights on this route include:

    • Delta
    • Alaska Airlines

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

    Flying via Denver Intl (DEN) gives the shortest average 1-stop total travel time at 8h 21m, 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.

  • Which popular places can I visit in Boston?

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

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

    Among airlines operating Seattle to Boston flights:

    • Delta: offers extra legroom; offers free seat selection
    • Alaska Airlines: offers extra legroom; offers free seat selection
    • JetBlue: offers extra legroom; offers free seat selection
    • American Airlines: offers free seat selection

    Extra legroom and free seat selection availability depends on fare class and route.

  • 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 carry-on bag and a checked bag in Economy Class
    • Alaska Airlines: a carry-on bag and a checked bag in Economy Class
    • American Airlines: a carry-on bag and a checked bag in Business Class

    Baggage 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?

    Moving around the Logan airport is the least of your worries since the airport provides free bus services. They ferry travelers to various spots at varying intervals. The buses are easy to board and to load luggage, thanks to their low floors. They also have a wheelchair lift, making them friendly to the disabled. You’ll find them to the south of each terminal.

  • What assistance can I get at the Seattle airport?

    The airport works toward giving travelers a memorable experience when waiting for their flights. You can find advanced facilities and welcoming staff to help you move around and offer you all the assistance needed. The disabled can access wheelchair services, which the airport provides at no cost upon making a reservation.

  • How fast can I get accommodation upon landing at Logan airport?

    You can get accommodation near Logan airport for approximately $144. Take a free shuttle bus at the terminals to access hotels such as the Homewood Suites, located 3.5 miles away. Enjoy an indoor pool table, Wi-Fi, and a fitness center. The hotel serves complimentary breakfast too.

  • What can keep me busy as I wait for my flight to Seattle Airport?

    Travelers can enjoy a walking tour to explore attractions in the neighborhood using underground paths and learn about the history. Waiting for your flight does not have to be boring, as there is too much fun around the airport.

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 Sunday. On this route, Tuesday flights average C$ 589, about C$ 138 less than Sunday fares (19% 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 C$ 540 round-trip in that month – typically C$ 253 less than the most expensive month, which is December (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 C$ 390 round-trip on this route – about C$ 259 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.

    • Hyatt Regency Boston Harbor
    • Hilton Garden Inn Boston Logan Airport
    • Hilton Boston Logan Airport
  • Seattle International Airport offers tranquil air services to travelers flying to Boston. You can book one among the several nonstop flights and land at Logan International Airport. Airlines operating on this route include Alaska and American Airlines.
  • If you are departing from Seattle airport, you can park your car and fly with your keys. You’ll find dedicated staff to assist you in parking and even carry your bags to the airport. What more, you enjoy a complimentary bottle of water as you head to the terminals.
  • While at Seattle airport, you can enjoy free Wi-Fi and take snacks and drinks at the elegant lounges that the facility has to offer. You can book your lounge tickets that cost around $49. At Courtyard A, you’ll find the Club Sea lounge that serves beer and other beverages.
  • Seattle airport features multiple artistic works that include photography, sculpture, and painting, among others. Travelers can explore creative artwork by reputable artists such as Robert Rauschenberg.
  • Travelers enjoy a variety of dining services as they wait to depart from Seattle International Airport. There are gift shops, fashion brands, and duty-free services offered at the waiting halls.
  • For those travelers with young kids, Seattle airport provides nursing rooms located in various areas. Find one in the Children Play Area at Concourse A. Another nursing room exists in Concourse D next to D24. You’ll also find one above checkpoint 3.
  • Travelers landing at Logan International Airport can access the United Club lounge located in Terminal B at $59 for adults. The lounge serves drinks, premium food, snacks, and breakfast. Other services include printing, photocopies, and free Wi-Fi.

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 nonstop 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 nonstop flights

More options for your flight from Seattle to Boston

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