$119 Find Cheap Flights from Seattle to Portsmouth

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Seattle to Portsmouth departing on 10/3. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
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Cheap Flights from Seattle to Portsmouth (SEA-BOS)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Seattle to Portsmouth that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Seattle to Portsmouth

Sat, Oct 18 - Fri, Oct 24
JetBlue Logo
1:10 pm - 9:46 pmSEA-BOS
5h 36mnonstop
JetBlue Logo
8:20 am - 11:59 amBOS-SEA
6h 39mnonstop
$175JetBlue
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Sat, Oct 18 - Fri, Oct 24
JetBlue Logo
1:10 pm - 9:46 pmSEA-BOS
5h 36mnonstop
JetBlue Logo
8:20 am - 11:59 amBOS-SEA
6h 39mnonstop
$178JetBlue
Find Deal
Sat, Oct 18 - Fri, Oct 24
JetBlue Logo
1:10 pm - 9:46 pmSEA-BOS
5h 36mnonstop
JetBlue Logo
8:20 am - 11:59 amBOS-SEA
6h 39mnonstop
$181JetBlue
Find Deal
Tue, Sep 30 - Sat, Oct 4
American Airlines Logo
11:05 pm - 10:10 amSEA-BOS
8h 05m1 stop
American Airlines Logo
12:52 pm - 8:09 pmBOS-SEA
10h 17m1 stop
$197American Airlines
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Thu, Oct 30 - Tue, Nov 4
Alaska Airlines Logo
3:59 pm - 12:20 amSEA-BOS
5h 21mnonstop
Alaska Airlines Logo
7:00 am - 10:35 amBOS-SEA
6h 35mnonstop
$205Alaska Airlines
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Fri, Oct 24 - Fri, Oct 31
American Airlines Logo
10:54 pm - 12:24 pmSEA-BOS
10h 30m1 stop
American Airlines Logo
5:24 am - 1:46 pmBOS-SEA
11h 22m1 stop
$207American Airlines
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Fri, Oct 24 - Fri, Oct 31
Delta Logo
10:05 pm - 6:35 amSEA-BOS
5h 30mnonstop
Delta Logo
7:20 am - 10:45 amBOS-SEA
6h 25mnonstop
$217Delta
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Sat, Oct 18 - Fri, Oct 24
Alaska Airlines Logo
3:35 pm - 11:59 pmSEA-BOS
5h 24mnonstop
Alaska Airlines Logo
8:25 pm - 10:34 amBOS-SEA
17h 09m1 stop
$227Alaska Airlines
Find Deal
Sat, Oct 18 - Fri, Oct 24
Hawaiian Airlines Logo
3:35 pm - 11:59 pmSEA-BOS
5h 24mnonstop
Hawaiian Airlines Logo
6:15 am - 2:35 pmBOS-SEA
11h 20m1 stop
$234Hawaiian Airlines
Find Deal
Tue, Dec 9 - Fri, Dec 12
Hawaiian Airlines Logo
9:00 am - 5:20 pmSEA-BOS
5h 20mnonstop
Hawaiian Airlines Logo
7:00 am - 10:35 amBOS-SEA
6h 35mnonstop
$258Hawaiian Airlines
Find Deal
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Good to know

Low seasonFebruary
Cheapest flight$119
Best time to beat the crowds with an average 18% drop in price.
Most popular time to fly and prices are also 5% lower on average.
Flight from Seattle to Boston

When to book flights from Seattle to Portsmouth

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

FAQs for booking flights from Seattle to Portsmouth

  • Which airports will I be using when flying from Seattle to Portsmouth?

    When flying out of Seattle you’ll be using Seattle/Tacoma Intl. Portsmouth does not have its own airport so you’ll be flying into nearby Boston Logan Intl airport, which is 50.3 mi away.

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

    Direct flights cover the 2,487 miles separating Seattle and Portsmouth in about 5h 20m.

  • How many flights are there between Seattle and Portsmouth?

    36 direct flights run between Seattle and Portsmouth on a daily basis. On average, there are about 252 departures each week.

  • What’s the cheapest day of the week to fly between Seattle and Portsmouth?

    Consider leaving on a Saturday and avoid Mondays if you are looking for the best rates. For your return to Seattle, you’ll find the best rates on Thursdays and the most expensive ones on Fridays.

  • How does KAYAK find such low prices on flights from Seattle to Portsmouth?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Seattle to Portsmouth.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Seattle to Portsmouth?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Portsmouth from Seattle is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Seattle to Portsmouth?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Portsmouth with an airline and back to Seattle with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Seattle to Portsmouth?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Portsmouth from Seattle up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • Which airlines provide the cheapest flights from Seattle to Portsmouth?

    In the last 72 hours, the cheapest one-way ticket between Seattle and Portsmouth found on KAYAK was with United Airlines for $119. JetBlue offered a round-trip connection from $175 and American Airlines from $197.

Top tips for finding cheap flights from Seattle to Portsmouth

  • There is no airport in Portsmouth. Instead, you’ll be flying into Boston Logan Airport when flying between Seattle and Portsmouth.
  • The cheapest flight from Seattle to Portsmouth was found 70 days before departure, on average.
  • Book at least 1 week before departure in order to get a below-average price.
  • High season is considered to be November, December and January. The cheapest month to fly is January.

Reviews of the top 5 airlines serving Seattle to Portsmouth

 
Need help choosing which airline to fly with from Seattle to Portsmouth? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
Alaska AirlinesOverall score based on 10000 reviews
7.8Comfort
7.0Entertainment
7.1Food
8.5Crew
8.1Boarding
Airline reviews

All flights were on time. No crowded and had empty seats. All flight attendents were great.

10.0 ExcellentAnonymous, Sep 2025SEA - SAN
Read more Alaska Airlines reviews

All flights were on time. No crowded and had empty seats. All flight attendents were great.

Flight was delayed as it always is with Alaska airlines. Particularly to smaller airports. No AC on the plane so it was miserably hot.

Slow boarding and the flight crew hit me with the food cart

It was very nice flight going to Seattle and coming back to Omaha. Even got in early. Very easy to check in using the Alaska Airlines App. Thank you.

They offer the only direct flight from Seattle to Pittsburgh.

Seattle airport is a mess. New bag tag system has potential, but you need more signage to guide passengers through the process as to where to go next. Told to go in one direction and then met with a very rude agent when we did. He blamed his attitude on all the folks flying over labor day that were paying his salary. Gate area for D3 is a mess compared to the North terminal. Overall Alaska is number 1 in my book.

After we boarded there was quite a long time before we actually took off, and there were no announcements from crew about why we were delayed. Later when they did make announcements they were largely inaudible. There was no food (other than for purchase) on the flight and no entertainment. Thats not a complaint, just explaining my ratings in those categories. The flight was smooth. Baggage claim was rapid.

The airline staff was great! The best safety review ive ever had!

Agent boarding us in San Diego lectured me on showing up on time for the flight, and said that if I had been three minutes later, he would have denied myself and my wife boarding. Our trusted traveler numbers were not in the system, even though I entered them when I bought the tickets. Our food orders were not in the system, even though I entered them prior to the flight. My wife requires a wheelchair, and that was delayed on both flights.

Why was I charged for a glass of wine on one flight and not on another? Why no movie or TVs? It was a long flight.

Perfect flight both ways. On time, courteous staff, plane comfortable and cool. Best domestic flights I’ve had in awhile.

Really low quality food especially for an international flight. The crew also was surprisingly unpleasant except couple of ladies. I know we were not in first class but that’s no reason to treat customers as less.

Flight delayed for two and half hours and then canceled altogether due to mechanical issues. No mechanic onsite to fix so had to send one from LAX.

Crew was good. The reservation got mixed up and they didn't have my TSA number. I am also a Silver Medallion and wasn't able to use Sky Priority.

Delta made it easy, comfortable and timely. The crew was fantastic.

This route with Delta always has delays or is cancelled. Aircrafts seem smaller and older. I fly Delta quite a bit - haven’t had issues with the international flights. But this route has always been the troublesome one

Three seats in first class were broken and while they were able to still acommodate us it was looking very touch and go and they had others they could not acommodate

Mechanic delay in addition to a 2 hour change in takeoff time was frustrating.

Delayed due to thunderstorms and no in-flight service due to rough weather — both of which are out of Delta’s control. Flight was good overall.

The flight attendants in SLC were rude. I arrived 40 minutes early to gate. Ticket said I needed check in for seat assignments and tried check in and attendants said they weren’t doing it. And proceeded to never call me to give me a ticket so when time to board I received the very last seat. Please relay to employees to do their job better..,

First class ticket. They ran out of food and I sat hungry watching the others eat

They we able to seat my companion and I next to each other. Plane’s temperature was very cool. Willl be more prepared on return trip.

All was good and they were able to seat my travel companion next to me. Thank you.

Like the ample leg room. May as well not bother with snacks if it's only a two ounce bag of pretzels. Didn't use the entertainment option. Was there one?

What an amazing flight. I haven’t experienced this level of service in a flight in years. This will be the only way to fly to Hawaii for me in the future.

Kayak sold me a ticket after check in time. Could not check in. Could not get on flight.

Love you guys are so friendly and kind and wonderful

Agents talk too fast over intercom. I know it’s memorized and we’ve all heard it before. Just slow down a little. Stop charging for checked bags. I was pleased to get my bags promptly at each end of my flight.

Everything was great except having to check in at Alaska. That was a surprise and took extra time and effort. Should have been explained somewhere maybe on the HA electronic ticket.

It was clean and the crew was great. I wish the chairs could recline just a little more and you would provide small pillows for people with bad backs. My back is fused and a little support would be great.

Given it’s a red-eye into Charolotte, we didn’t get any food. The survey does not include “N/A” so the rating will be skewed.

Great. Quick and quiet and east. The breakfast choices were a welcome surprise!

American airlines suck they delay the flights all the time made me sleep in an airport because my flight was delayed and I miss my connecting flight

There's nothing I liked about it. For first off I scheduled this trip two weeks in advance then they delayed my flight which messed up my whole trip. So I scheduled it for the following weekend thinking there won't be a delay and guess what as soon as I got to the airport we said in the airplane on the tarmac for an hour and a half. Not only was it delayed I missed my connecting flight meaning I had to stay the night at Dallas-Fort Worth airport sleeping on the floor. I will tell you this I will never fly American airlines ever again I have had nothing but horrible experience with them and I just throw money at them

The stewardess hit me with the food kart twice on the head and didn't say I'm sorry once. The same stewardess gave me a warm Apple Juice with No ice. The Flight was delayed for Departure 6 times, starting from 2:36pm, finally taking off 7:50pm. I was late picking up my child from the sitter by 3 hours.

Having to reschedule flights a day later, they loaded by luggage on the wrong plane from Little rock now I have to HOPE they deliver it to where im staying like they said would. International flight crew was very disgruntled and not very friendly.

We will be writing a long, detailed letter to corporate about our awful experience with American airlines.

It took way too long to diagnose and solve the problem of a broken crew member cabin seat. Though compensation for the volunteer who left the flight was very kind.

The entertainment package was vast and the selections were very current. Keep updating it was great.

The seat was so hard my tailbone was aching The crew was kind of a b**** because I made a joke that I didn't care if they close the door I total c*** when she was trying to f****** act like she was mad at me because I said that The flight was bumpy. Sure you didnt have control over that.

They have the most inexperienced / rude flight staff I’ve encountered

very difficult boarding process - aggressive passengers not the friendliest crew

WiFi was not eorkig (again) And the plane was from 1990 with the screens which were.not touch and most didn’t even work and if lucky could tune in tv

I paid extra for a seat closer to the front. The TV didn’t work at all for the entire flight. Would have been nice to know before I purchased an “upgraded “ seat

It was great. I had never flown on JetBlue before, but would be very happy to fly with them in the future.

Worst flight experience ever flights canceled. JetBlue told us just did not even bother standing in line to come back in one and a half hours then without any information we had to go pick up all of our luggage and spend over $2000 in accommodation just to get home. JetBlue said that the next flight available for us to get home would be three days later. Absolutely absurd hasn’t offered to give us any compensation do not fly JetBlue horrible company. They said it was based on the weather and the weather is great in all locations that we would’ve been flying to total hoax. I think it’s a conspiracy theory.

The captain gave good announcements and the flight attendants were friendly. The WiFi was pretty good. The plane itself looked very old inside and the seats were very uncomfortable. The screens in the seat backs were the smallest I’ve ever seen. There were so many loud and obnoxious kids on this flight and the parents didn’t do much to try to quiet them down. Some had videos and games on tablets with higher than necessary volume going the whole time.

Too many long delays with JetBlue. Worst major airline that serves JFK but unfortunately I keep going back because of the prices.

My JetBlue experience was nice. The flights ran on time, the aircraft was clean and comfortable, and the flight attendants were attentive. My only issue, which is isolated to the low-cost (budget) option at JetBlue, is that the check in process makes the user feel that they have to buy their seats. The seats offered for purchase are upgrades from the budget seats you get (which are essentially the last seats remaining). The interface should not make it feel like you must purchase a seat.

The plane was late to leave.. Internet was lousy. TV was not working. when we arrived, We stayed on the plane for a long time before we got to the gate. It took us a long time to retrieve our luggage because they didn’t know what carousel to send them to. It was a bad experience.

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