$154 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 3/2. 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.
1 adult
1 adult, Economy, 0 bags

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Everything you should know

Cheapest round-trip
$290
Overall average: $287
American Airlines
Wed 3/11Wed 3/18
SEA - BOS • 1 stop
Cheapest non-stop
$296
Typical prices: $253-$459
JetBlue
Tue 5/19Sun 5/24
SEA - BOS • Non-stop
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Flight Deals
Useful Info
Flight Deals

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

Wed, Mar 11 - Wed, Mar 18
American Airlines Logo
12:07 am - 11:28 am
SEA
-
BOS
8h 21m
1 stop
American Airlines Logo
5:31 pm - 12:24 am
BOS
-
SEA
9h 53m
1 stop
$290American Airlines
Tue, Feb 24 - Tue, Mar 3
Delta Logo
10:20 pm - 6:50 am
SEA
-
BOS
5h 30mnonstop
Delta Logo
6:05 am - 7:38 pm
BOS
-
SEA
16h 33m
1 stop
$291Delta
Mon, Feb 23 - Tue, Mar 3
American Airlines Logo
11:57 pm - 11:54 am
SEA
-
BOS
8h 57m
1 stop
American Airlines Logo
12:15 pm - 6:29 pm
BOS
-
SEA
9h 14m
1 stop
$292American Airlines
Wed, Mar 11 - Wed, Mar 18
American Airlines Logo
12:07 am - 10:46 am
SEA
-
BOS
7h 39m
1 stop
American Airlines Logo
2:40 pm - 9:57 pm
BOS
-
SEA
10h 17m
1 stop
$293American Airlines
Sat, Feb 14 - Tue, Mar 17
United Airlines Logo
12:32 pm - 12:49 am
SEA
-
BOS
9h 17m
1 stop
United Airlines Logo
2:15 pm - 8:56 pm
BOS
-
SEA
9h 41m
1 stop
$294United Airlines
Tue, May 19 - Sun, May 24
JetBlue Logo
11:30 am - 8:05 pm
SEA
-
BOS
5h 35mnonstop
JetBlue Logo
7:00 am - 10:20 am
BOS
-
SEA
6h 20mnonstop
$296JetBlue
Wed, May 20 - Sat, May 23
Delta Logo
4:05 pm - 12:37 am
SEA
-
BOS
5h 32mnonstop
Delta Logo
11:40 am - 2:49 pm
BOS
-
SEA
6h 09mnonstop
$297Delta
Wed, Mar 18 - Wed, Mar 25
Alaska Airlines Logo
11:30 am - 5:53 am
SEA
-
BOS
15h 23m
1 stop
Alaska Airlines Logo
7:15 am - 10:40 am
BOS
-
SEA
6h 25mnonstop
$300Alaska Airlines
Tue, Mar 17 - Wed, Mar 18
Delta Logo
7:15 am - 5:32 am
SEA
-
BOS
19h 17m
1 stop
Delta Logo
6:45 pm - 10:10 pm
BOS
-
SEA
6h 25mnonstop
$301Delta
Tue, Feb 24 - Wed, Mar 4
Delta Logo
10:20 pm - 6:50 am
SEA
-
BOS
5h 30mnonstop
Delta Logo
6:05 am - 7:38 pm
BOS
-
SEA
16h 33m
1 stop
$302Delta
Useful Info

Good to know

Low seasonJanuary
Cheapest flight$154
Best time to beat the crowds with an average 9% drop in price.
Most popular time to fly with an average 6% increase in price.
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

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

Insights shared by verified travelers who flew the route from Seattle to Portsmouth 
rsmrostovFlew with Alaska Airlines
SEA
-
BOS
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
SEA
-
BOS
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.

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 14m.

  • How many flights are there between Seattle and Portsmouth?

    28 direct flights run between Seattle and Portsmouth on a daily basis. On average, there are about 196 departures each week.

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

    Consider leaving on a Tuesday and avoid Sundays if you are looking for the best rates. For your return to Seattle, you’ll find the best rates on Tuesdays and the most expensive ones on Sundays.

  • 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 American Airlines for $98. Hawaiian Airlines offered a round-trip connection from $118 and JetBlue from $123.

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 27 days before departure, on average.
  • Book at least 2 weeks 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 March.

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 11825 reviews
8.1Boarding
7.0Entertainment
7.8Comfort
8.5Crew
7.1Food
Airline reviews

I think Alaska should start including free meals on these longer trips.

6.0 GoodAnonymous, Feb 2026
SEA - DCA
Read more Alaska Airlines reviews

I think Alaska should start including free meals on these longer trips.

Wheelchair assistance was excellent. I had a saver fare, but was given a seat in Premium. So very nice!! Extra legroom, complimentary beer. The flight crew was very nice and efficient. The gate agent in Seattle double checked to make sure I was able to board the plane all right while using my cane. I boarded first. So considerate! The flight was smooth, and right on time.

There is nothing critical to complain about but I would say the snacks are pretty bad Airline staff could be aggressive the way they move through the aisles and the plane I also got hustled for a small wallet size men bag and force the consolidated with my carry on item we're talking about a wallet size bag.

Departed on time and had an efficient boarding process. The inflight wifi was not working on one of the flights.

How can I review what was denied to me. Instead of offering to let me pay for the ticket I got booted of my flight with no way home and no choice but to purchase another ticket for 12 hours later. Filing a complaint with the DOT

From Las Vegas to Boise all went well. However, our flight was delayed in Boise and I missed my connecting flight from Seattle to Pasco. Moreover, the last flight to Pasco was full and I was booked on the 11:30 flight Sunday and given a hotel accommodation. However, I was scheduled to deliver the Sunday morning service at my church and needed to arrive no later than 10:00. Therefore, I booked a Delta flight scheduled to arrive in Pasco at 23:09. My piece of luggage checked in Las Vegas arrived in Pasco earlier today. I waited at the airport for over an hour last night to speak with an Alaska agent to no avail. I went back after church this morning in search of my piece of luggage and it could not be located. After waiting for 40 minutes to speak to the agent authorized to take my claim, he announced that he was closing the counter to assist on the flight line but not before providing me with a telephone number that would help me with filing my claim. Before I was able to make the call (due to other factors) I received a call from Alaska agent informing me that my luggage had just arrived and I am now waiting for it to be delivered. I deliberately took the more complicated route home to ensure that I would be home in plenty of time to prepare for myself for the Sunday service and accommodate my relatives’ needs. I believe the airport is undermanned given the number of flights coming in and going out. It was fiasco last night with three flights waiting for luggage and another flight landing within minutes. Today’s problems stemmed from a lack of cross training and a serious amount of cargo/baggage going out and too few people scheduled to cover.

The cabin crew was absolutely wonderful, the service was great and it was just a good flight overall.

I like them since I live in Alaska and I don't have much choice

The flight attendants were nice, but the cabin and seats were uncomfortable.

Food was terrible, noisy plane & would never pay to fly first class again. Seats in regular price are too small, no leg room & center aisle much too, too small. Seats in 1st class larger but not comfortable.

I didn't take this flight. I changed the flight. Why am I getting surveys and notifications on flights that I change. Seems like a defect with Kayak.

Delta One is extraordinary. I fly business when somebody hires me. I just wonder why there is such a chasm between business class and the insanely inhumane and nonsensical coach. The seats are not large enough to fit even my tiny wife. We fly 10% of what we did because we don’t want to pay 5-10 k but for $400 it’s unbearable. It seems like the accountants took over and made stupid decisions. Screw in 20 extra seats and make it so unbearable that people fly 90% less. Just put the damn price up and put some proper chairs in. But business, yay.

Timing, quality of service, promptness and courtesy of the staff

It was last minute due to weather - considering - it was amazing! Good smiles, friendly staff and they were making sure we knew what was going on when and where.

delta last minute gave me a boarding pass for a different flight with no confirmation that they were changing it

The service from the flight attendants were of supreme quality. They greeted and treated everyone with a wide smile. This is totally absent nowadays. Kudos to them!!!!

Excellent flight and got us around tough weather. Only issue was seat TV did not work and crew tried to reboot.

Very large passenger too space from my own seat. Arm board couldn’t be lowered because of his size. It wads very uncomfortable trip, as the flight was full couldn’t move anywhere having back pain because of the position in which I was the entire flight.

was sitting in the jet bridge for 10 minutes in -20 degree weather waiting for my bag

Outdated equipment in disrepair, wifi inoperable. Broken seats, taped air vents, generally poor condition, the 717 showed its age and lack of upkeep.

Yall need to integrate your system with Alaska more efficiently. They booted me off the first flight because of a discrepancy on your end.

The crew at Hawaiian Airlines was fantastic. Kind and hard working. The pilots were great with giving us all the updates to make sure we were informed.

Very good. Nice plane and we sat in economy plus - bigger seats, more room. They served a meal and snacks, and the meal was an apple stuffed pancake that was very good! The snack for us was a hummus sandwich - also very good. The flight attendants were helpful and nice. They have plenty of movies and shows to watch. My only negative -- they changed our flights around and did not adjust the layovers, so we ended up with a very long and unnecessary layover in Honolulu.

I liked the Starlink WiFi but didn't like how they said they were the only airline to offer a free meal and it turns out to be just a standalone sandwich and then charge for snacks to go with it. Rather have the free snacks like Southwest, but have the option to purchase a decent meal for a 5+ hour flight.

Flight scheduled to take off at 5.55pm but it did not take off until 7pm due to some food delivery delay.

Unfortunately, I was put into the middle seat in the first row of premium seating. Sounds nice right? No! that is the worst seat in the plane. I wish I was in economy rather than be in that seat! There is no seat back pocket, no tray table, no charger. Nothing! so unless you're row mates are willing to let you share their basic amenities any flyer should have, you are stuck. It was the worst experience ever! And the flight attendant forgot to take my drink order. I felt like the forgotten flyer.

Delayed and cancelled flights were hard and very stressful, both ways!

The crew was quite good, they came by often with drinks or to collect trash. But what wasn't nice was the flight was over weigh and several people had to be rebooked. I was questioned whether I should have a seat when I was getting to it. The in-flight entertainment kept buffering and interrupting. And the route took the airplane through high winds which caused us a longer flight

Wasn’t on the flight due to Alaska cancellation…also after all the rerouting, I was going to be on a later flight that left SFO at 7:47pm, which meant an almost 6 hour layover. That same Hawaiian flight was delayed for another 2hours.

I had to cancel the flight because with a 3 hour delay for 'unexpected maintenance' in getting to LAX, I couldn't connect to an overseas flight that I had booked on Scandinavian Air.

Update to handle the delay was very bad, crews no smiles or welcome or thanks. Don’t care attitude

It would be nice to have some low carb options in the snacks.

I was trying to take 2 one and a half hour one way trips and I experienced almost 20 delays over the course of those two trips. Only a few of them were due to weather the rest was disorganization

No gates avail at DFW so our incoming had to wait 30 mins for a plane to push back because they Had mechanical. We boarded 90 mins delayed and then we had a mechanical. Come on American…do better. Also at my seat the tray table had not been cleaned. Floor had not been cleaned. But captain and flight Att were very picture and apologetic.

Crew was helpful and cheerful especially when they had no refreshments to work with. The plane was never serviced and had nothing but limited water and coffee onboard. For the price point, a concern of services.

Flight was smooth, quick and felt safe. The 2 delays not happening would have been better but I guess that happens in the airline industry

Flight was canceled. I asked to be rerouted to OKC and then took an Uber.

AA did not allow to board a flight because my connecting flight from DFW had been canceled. I got on another flight to another city. No service on the plane and I did not use their entertainment system.

On time on a day with lots of weather cancellations on other flights. Thank you for getting me home during a winter storm!

Don't change gate multiple times make people run across the airport. Announce delays in a timely manner. Have maintenance crew ready. Don't delay and keep passengers on the plane for 3 hrs. on tarmac.

Friendly crew, efficient boarding and flight arrived early. Couldn’t ask for a better experience

Terrible. They canceled our early morning flight after midnight on the day of and had no available flights to rebook my family on for the next 72 hours. Yet they still had other flights that were not cancelled from JFK so it couldn’t be based on the weather. It felt like they canceled the flight based on it not being profitable enough for them. I am not interested in traveling with the again. The absolute worse customer service and lack of accountability.

Horribly rude check in at airport, worst in 25 years of flying. All over a simple issue they could have googled to resolve.

First time flying with JetBlue and never again. I went to the counter to request meet and assist because I'm 74 and my wife is 79. I walk with a cane and my wife is handicapped and has her own wheel chair. I told the agent that my wife and luggage was at the entrance door. The ticketing agent said to me that they don't offer meet and assist. I need to bring them our luggage and then go back and get my wife in order to get my boarding pass. As I went back to get my luggage a Southwest agent along with a TSA agent recognized the situation and came over and took my wife and luggage to the JetBlue ticketing counter alongside the line and told the JetBlue agent to issue to take our luggage as soon as they could.

1) No pilot available for 1 hour 2) no room for most passengers careyon in overhead—-> stowed below 3) when we landed we had to wait 45 min. Before docking at gate as gate was not ready

It was good. I prefer JB over other airlines.I just wish we had headphones for the films, but other than that - good.

The ride share experience in JFK is terrible. After traveling on a flight, then you need to take a subway to the last stop to get an uber or lyft. Unacceptable. Bad job JetBlue for permitting JFK and Port Authority to do this to your passengers.

The flight was two hours late due to a computer fault and resulting maintenance. Nothing was offered as compensation beyond bottles of water during the time we were deplaned and waiting in the terminal.

Very pleasant flight attendants. Gate crew rather loud chatting with each other.

Four plus hour flight delay in New York caused us to take off after 11:30pm. We didn’t arrive at our hotel until five hours after check in. Started the trip off feeling exhausted.

Everything you need to know for your flight from Seattle to Portsmouth

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