BOS - SEA

C$ 242 Find Cheap Flights from Boston to Seattle – Compare and Save

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Everything you should know

Cheapest round-trip
C$ 443
Typical prices: C$ 486-C$ 765
Southwest
Sun 21/10Sun 4/11
BOS - SEA • 2 stops
Cheapest direct flights
C$ 486
Typical prices: C$ 489-C$ 770
JetBlue
Sun 7/10Wed 10/10
BOS - SEA • Direct
Advice from real travellers
JetBlue adds free Wi-Fi; Delta offers member Wi-Fi and Comfort Plus legroom.
Alaska's baggage guarantee stands out; pay for seat selection on full flights.
Expert advice
+1
Expert advice
+1
Direct flights
You can fly direct with Delta, Alaska Airlines, and JetBlue. Average duration is 6h 21m
Direct flights
+1
Direct flights
+1
Avoid delays
Most punctual • 84% on-time
Best time • Fewest delays
Insights
Insights
When to book
in advance
Our data shows that travellers who book at least 14 weeks in advance save around 36% compared to booking last minute.
Insights
Insights
When to travel
Cheapest • 18% price drop
Most popular
Good to know
+1
Good to know
+1
Top layover airports
Cheapest • Avg C$ 391 (round-trip)
Shortest trip • 8h 19m (one-way)
Insights
Insights
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We hope you enjoy your trip to Seattle!
Flight Deals
Booking Insights
Expert advice
Flight Deals

Cheap Flights from Boston to Seattle (BOS-SEA)

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

Recent round-trip flight deals from Boston to Seattle

Wed, 21 Oct - Wed, 4 Nov
Southwest Logo
1:15 p.m. - 10:40 p.m.BOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
12h 25m2 stops Nashville Intl Denver Intl
Southwest Logo
7:45 a.m. - 10:30 p.m.SEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
11h 45m2 stops Las Vegas Harry Reid Intl Chicago Midway
C$ 443Southwest
Wed, 7 Oct - Tue, 27 Oct
Southwest Logo
5:35 a.m. - 2:20 p.m.BOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
11h 45m2 stops Baltimore/Washington Denver Intl
Southwest Logo
12:10 a.m. - 11:10 a.m.SEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
8h 00m1 stop Chicago Midway
C$ 446Southwest
Wed, 7 Oct - Tue, 27 Oct
Southwest Logo
5:15 a.m. - 2:20 p.m.BOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
12h 05m2 stops Lambert-St Louis Denver Intl
Southwest Logo
12:10 a.m. - 2:55 p.m.SEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
11h 45m2 stops Chicago Midway Baltimore/Washington
C$ 453Southwest
Tue, 3 Nov - Tue, 3 Nov
Alaska Airlines Logo
7:03 a.m. - 5:55 p.m.BOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
13h 52m1 stop San Diego
Alaska Airlines Logo
9:20 p.m. - 5:40 a.m.SEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
5h 20mdirect
C$ 454Alaska Airlines
Thu, 29 Oct - Thu, 5 Nov
Southwest Logo
10:50 a.m. - 9:05 p.m.BOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
13h 15m1 stop San Diego
Southwest Logo
11:10 a.m. - 11:55 p.m.SEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
9h 45m2 stops Sacramento Intl Baltimore/Washington
C$ 460Southwest
Thu, 15 Oct - Mon, 19 Oct
Southwest Logo
4:50 p.m. - 12:40 a.m.BOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
10h 50m1 stop Chicago Midway
Southwest Logo
12:10 a.m. - 12:30 p.m.SEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
9h 20m1 stop Chicago Midway
C$ 465Southwest
Thu, 29 Oct - Thu, 5 Nov
Southwest Logo
2:35 p.m. - 12:40 a.m.BOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
13h 05m2 stops Baltimore/Washington Chicago Midway
Southwest Logo
11:10 a.m. - 11:55 p.m.SEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
9h 45m2 stops Sacramento Intl Baltimore/Washington
C$ 467Southwest
Thu, 12 Nov - Thu, 12 Nov
Alaska Airlines Logo
7:03 a.m. - 5:55 p.m.BOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
13h 52m1 stop San Diego
Alaska Airlines Logo
9:20 p.m. - 5:40 a.m.SEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
5h 20mdirect
C$ 471Alaska Airlines
Thu, 15 Oct - Mon, 19 Oct
Southwest Logo
4:50 p.m. - 12:40 a.m.BOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
10h 50m1 stop Chicago Midway
Southwest Logo
12:10 a.m. - 2:55 p.m.SEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
11h 45m2 stops Chicago Midway Baltimore/Washington
C$ 474Southwest
Sat, 17 Oct - Wed, 21 Oct
JetBlue Logo
1:00 p.m. - 9:21 p.m.BOS  Boston Logan Intl-SEA Seattle/Tacoma Intl
11h 21m1 stop New York John F Kennedy Intl
JetBlue Logo
10:15 p.m. - 11:01 a.m.SEA  Seattle/Tacoma Intl-BOS Boston Logan Intl
9h 46m1 stop New York John F Kennedy Intl
C$ 477JetBlue
Booking Insights

Price, demand, and travel trends for Boston to Seattle flights

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

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

Round-trip flights from Boston to Seattle start at C$ 443. Prices are below average for this route right now, with typical round-trip fares ranging from C$ 486 to C$ 765. The lowest price found in the past 5 days was C$ 443 on Southwest.

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

Wednesday is the cheapest day of the week to fly from Boston to Seattle and is 6% cheaper than the average day. Monday is the most expensive day with flight prices 12% higher than average. Based on deals found by KAYAK users in the last 12 months.

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

  • March is the cheapest month to fly from Boston to Seattle at C$ 499 round-trip.
  • December (C$ 739) and July (C$ 671) are the most expensive months.
  • The price difference between flying in the cheapest and most expensive months is 48% on average.
This is based on KAYAK aggregated and averaged internal data over the past 12 months.

When are prices from Boston to Seattle the cheapest?

Flights from Boston to Seattle are cheapest 14 weeks before departure. Booking in this window typically costs about 36% 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 Boston to Seattle

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

Harriet Baskas

Expert on Alaska Airlines, JetBlue 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 Boston to Seattle flights

Low season

February

Cheapest flight

C$ 242
Best time to beat the crowds (12% less expensive on average)
Most popular time to fly (10% more expensive on average)
Flights from Boston to Seattle

When to book flights from Boston to Seattle

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

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

Insights shared by verified travellers who flew the route from Boston to Seattle 
Verified travelerFlew with Alaska Airlines-Aug 2026
Be prepared to wait if there's any weather going on at either airport. Bring a book and snacks! You'll need them! Also, airport charges like $10-13 for a pb&j!!! Bring your food.
Verified travelerFlew with Alaska Airlines-Mar 2026
Other smaller airports in the area may be more convenient, but the nonstop from Logan and the red-eye from Seattle suit me better than switching to connecting flights.
Verified travelerFlew with Alaska Airlines-Oct 2024
Flying Alaska Airlines from Boston to Seattle was an example of getting exactly what you expect. A no-frills basic experience, but one where the important things were accomplished, timely departure, on-time arrival, no drama, no glitches, completely as anticipated. I paid a little extra for one offered perk (seat selection), and I'm glad I did because my early morning flight was full. Next time, I'll likely pre-order a snack, since they looked good, were served promptly, and are priced right.
CarlaFlew with Alaska Airlines-May 2024
It’s a good choice. Seattle airport is huge and confusing if you are changing planes. Have plenty of time to switch.

Your Boston to Seattle flight questions, answered

Find helpful route details based on KAYAK data, including flight times, airports, airlines, and booking questions.

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

    Among airlines operating Boston to Seattle flights:

    • JetBlue: offers extra legroom; offers free seat selection
    • Alaska Airlines: offers extra legroom; offers free seat selection
    • Delta: 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 are available on the route from Boston to Seattle?

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

    • Delta
    • Alaska Airlines
    • JetBlue

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

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

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

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

    • Alaska Airlines: a carry-on bag and a checked bag in Economy Class
    • Delta: a carry-on bag and a checked bag in Economy Class
    • JetBlue: a cabin bag in Economy Class class

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

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

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

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

    On this route, layover flights are cheaper than direct options on average. Layover fares average C$ 391 round-trip via New York John F Kennedy Intl (JFK), compared to C$ 612 for direct.

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

    There is no standard. Checked bag policies vary by airline on this route. Most carriers charge C$ 49–C$ 139 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 Boston to Seattle?

    The Airbus A321-100/200 family is used most often on this route, operated mainly by JetBlue and Delta. Other aircraft seen on the route include Airbus A321neo variants.

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

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

    • Philadelphia (PHL) – 31% of one-stop connections
    • Chicago O'Hare Intl (ORD) – 28% of one-stop connections
    • Minneapolis St Paul (MSP) – 13% of one-stop connections
    • Denver Intl (DEN) – 7% of one-stop connections

    Philadelphia (PHL) handles the largest share of one-stop connections on this route.

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

    Yes. Being flexible with your travel dates can save you up to 16% on the Boston to Seattle route. Wednesday is the cheapest departure day at C$ 577 round-trip on average, while Monday is the most expensive at C$ 686, a difference of C$ 110. KAYAK's flexible dates feature shows options up to 3 days before and after your selected dates, making it easier to compare nearby fares.

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

    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 Boston to Seattle route, 17% of flights were delayed in the past 3 months, with delays averaging 2 hours 53 minutes.

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

    Morning is the busiest departure period on Boston to Seattle flights, with 58% leaving in that window. Evening departures account for 28%, Afternoon flights for 14%, and Night flights for 0%.

  • Which popular places can I visit in Seattle?

    Some of the most popular sights in Seattle are Lumen Field, T-Mobile Park, and Seattle Waterfront. These are among the most viewed places in Seattle on KAYAK.

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

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

    • Earliest: departs at 7:00 am and lands at 1:21 pm
    • Latest: departs at 7:59 pm and lands at 2:20 am.

    The flight takes about 6h 21m.

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

    Last-minute fares on this route – booked within 2 weeks of departure – run 38% above the route average of C$ 608. Book 14 weeks before departure for the lowest fares.

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

    A direct flight from Boston to Seattle takes 6h 21m, covering 6,441 km.

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

    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.

  • Have flight prices from Boston to Seattle 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$ 2,316. That means the highest observed fare was about 5x higher than the lowest one.

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

    One-way fares from Boston to Seattle are currently lower than usual. Average one-way flight prices are about C$ 264, which is 28% below the typical average for this route.

  • How does Delta's on-time performance compare to other airlines on Boston to Seattle flights?

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

    • Delta: 84% on time
    • JetBlue: 83% on time
    • Alaska Airlines: 82% on time

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

  • How do delay rates compare for morning and evening flights from Boston to Seattle?

    Morning flights have the fewest delays on this route. Delays tend to pile up throughout the day as one late flight pushes the next, so earlier departures are usually more reliable.

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

    Flying via Chicago O'Hare Intl (ORD) gives the shortest average 1-stop total travel time at 8h 19m, compared with 8h 25m via Philadelphia (PHL) and 8h 25m via Chicago Midway (MDW).

  • What is the time difference between Boston and Seattle?

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

  • What car rental options are available at Seattle/Tacoma Intl Airport (SEA)?

    Seattle/Tacoma Intl Airport (SEA) hosts 5 major car rental companies, with daily rates starting from around C$ 5 for economy cars. Top options include:
    • Fox
    • Europcar
    • Thrifty
    • Budget
    • Dollar

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

    Round-trip flights from Boston to Seattle range from C$ 486 to C$ 765, with an average of C$ 608 over the past 12 months. Anything below C$ 486 counts as a good deal.

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

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

    • • JetBlue
    • • Alaska Airlines
    • • Delta

    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.

Your guide to booking Boston to Seattle 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 Wednesday departure instead of Monday. On this route, Wednesday flights average C$ 577 – about C$ 110 less than Monday (16% savings) based on the last 12 months.
  • For the best chance at a low fare, aim to book around 14 weeks before you fly. On this route, that window historically saves about 36% versus last-minute pricing (KAYAK booking data, last 12 months).
  • If you can choose when to travel, plan your Boston to Seattle trip for March. Fares historically average C$ 499 round-trip in that month – typically C$ 240 less than the most expensive month, which is December (based on the last 12 months).
  • If arriving on time is high on your priority list, Delta is the strongest pick on this route. 84% of Delta flights from Boston to Seattle arrived on time in the past 3 months, slightly above the route's average on-time arrival rate of 83%. When flights on this route do arrive late, the average delay is 2 hours53 minutes, so choosing a carrier with strong on-time performance can make a difference on tight schedules.
  • If you have the time, taking a 1-stop flight through New York John F Kennedy Intl Airport (JFK) can be cheaper than flying direct. The cheapest layover option averages C$ 391 round-trip on this route – about C$ 221 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 Seattle/Tacoma Intl Airport.
    - Seattle Airport Marriott
    - Coast Gateway Hotel
    - Fairfield by Marriott Inn & Suites Seattle Sea-Tac Airport

Prefer to fly direct from Boston to Seattle?

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

Direct departures

Boston Logan Intl to Seattle/Tacoma Intl

Monday

Alaska Airlines,Delta,JetBlue

Alaska Airlines,Delta, +1 more

Tuesday

Alaska Airlines,Delta,JetBlue

Alaska Airlines,Delta, +1 more

Wednesday

Alaska Airlines,Delta,JetBlue

Alaska Airlines,Delta, +1 more

Thursday

Alaska Airlines,Delta,JetBlue

Alaska Airlines,Delta, +1 more

Friday

Alaska Airlines,Delta,JetBlue

Alaska Airlines,Delta, +1 more

Saturday

Alaska Airlines,Delta,JetBlue

Alaska Airlines,Delta, +1 more

Sunday

Alaska Airlines,Delta,JetBlue

Alaska Airlines,Delta, +1 more

See more nonstop flights

Direct returns

Seattle/Tacoma Intl to Boston Logan Intl

Monday

Alaska Airlines,Delta,JetBlue

Alaska Airlines,Delta, +1 more

Tuesday

Alaska Airlines,Delta,JetBlue

Alaska Airlines,Delta, +1 more

Wednesday

Alaska Airlines,Delta,JetBlue

Alaska Airlines,Delta, +1 more

Thursday

Alaska Airlines,Delta,JetBlue

Alaska Airlines,Delta, +1 more

Friday

Alaska Airlines,Delta,JetBlue

Alaska Airlines,Delta, +1 more

Saturday

Alaska Airlines,Delta,JetBlue

Alaska Airlines,Delta, +1 more

Sunday

Alaska Airlines,Delta,JetBlue

Alaska Airlines,Delta, +1 more

See more nonstop flights

More options for your flight from Boston to Seattle

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