BOS - KGS

$818 Find Cheap Flights from Boston to Kos

This is the cheapest round-trip flight price found by a KAYAK user in the last 72 hours by searching for a flight from Boston to Kos departing on 4/18. 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

KAYAK searches hundreds of travel sites at once for deals on flights to Kos

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Boston to Kos, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Boston to Kos, as well as popular online travel agencies
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Everything you should know

Cheapest round-trip
$818
Multiple Airlines
сб 4/18пт 5/1
BOS - KGS • 2 stops
Cheapest one-way
Multiple Airlines
вт 1/27
BOS - KGS • multi-stop
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Flight Deals
Booking Insights
Flight Deals

Cheap Flights from Boston to Kos (BOS-KGS)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Boston to Kos 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 Boston to Kos

сб, квіт. 18 - пт, трав. 1
Multiple Airlines Logo
10:40 am - 9:45 pm
BOS
-
KGS
28h 05m
2 stops
Multiple Airlines Logo
10:25 pm - 9:27 pm
KGS
-
BOS
30h 02m
3 stops
$818Multiple Airlines
сб, квіт. 18 - пт, трав. 1
Multiple Airlines Logo
10:40 am - 9:45 pm
BOS
-
KGS
28h 05m
3 stops
Multiple Airlines Logo
10:25 pm - 9:27 pm
KGS
-
BOS
30h 02m
3 stops
$827Multiple Airlines
сб, квіт. 18 - пт, трав. 1
Multiple Airlines Logo
10:40 am - 9:45 pm
BOS
-
KGS
28h 05m
2 stops
Multiple Airlines Logo
10:25 pm - 10:39 pm
KGS
-
BOS
31h 14m
2 stops
$833Multiple Airlines
сб, квіт. 18 - пт, трав. 1
Multiple Airlines Logo
10:40 am - 9:45 pm
BOS
-
KGS
28h 05m
2 stops
Multiple Airlines Logo
10:25 pm - 2:55 pm
KGS
-
BOS
23h 30m
1 stop
$853Multiple Airlines
сб, квіт. 18 - пт, трав. 1
Multiple Airlines Logo
5:10 pm - 5:35 pm
BOS
-
KGS
17h 25m
2 stops
Multiple Airlines Logo
6:00 am - 3:10 pm
KGS
-
BOS
16h 10m
2 stops
$7,413Multiple Airlines
Booking Insights

KAYAK's insights & trends for Boston to Kos flights

Get data-powered insights and trends into flights from Boston to Kos to help you find the cheapest flights, the best time to fly and much more.

What is the most popular layover airport when flying from Boston to Kos?

Percentage of 1-stop round-trip flights from Boston to Kos chosen by KAYAK users via each layover airport in the last 12 months (only includes trips with the same layover airport on both legs).

Zurich (ZRH) is the top choice – 75% of KAYAK users who clicked on 1-stop flights from Boston to Kos picked an itinerary connecting there.

What is the cheapest layover airport when flying from Boston to Kos?

Average round-trip price for 1-stop flights from Boston to Kos clicked by KAYAK users in the last 12 months (only includes trips with the same layover airport on both legs).

Flights via Zurich (ZRH) offer the most affordable fares, with an average round-trip price of $1,251.

Which layover airport offers the shortest total travel time from Boston to Kos?

Shortest average total travel time for 1-stop one-way flights from Boston to Kos via different layover airports, based on KAYAK user data from the last 12 months.

Consider flying via Frankfurt am Main (FRA) for the shortest journey. The average one-way travel time for flights connecting there is 12h 45m.

Which layover airport has the quickest connection when flying from Boston to Kos?

Average layover duration at different layover airports for 1-stop one-way flights from Boston to Kos, based on KAYAK user data from the last 12 months.

If you prefer a quick connection, Frankfurt am Main (FRA) often has the shortest layovers from Boston to Kos, with an average of 2h 00m.

Good to know

Cheapest flight$818
Flight from Boston to Kos

When to book flights from Boston to Kos

Are your dates flexible? Find out the best times to travel from Boston to Kos based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking flights from Boston to Kos

  • What is the cheapest flight from Boston to Kos?

    In the last 3 days, the lowest price for a flight from Boston to Kos was $818 for a round-trip ticket.

  • Do I need a passport to fly between Boston and Kos?

    Yes, you'll most likely have to show a valid passport before boarding the plane in Boston and on arrival in Kos.

  • Which aircraft models fly most regularly from Boston to Kos?

    We unfortunately don’t have that data for this specific route.

  • Which airline alliances offer flights from Boston to Kos?

    Star Alliance is the only airline alliance operating flights between Boston and Kos.

  • Which is the best airline for flights from Boston to Kos, SWISS or Lufthansa?

    The two airlines most popular with KAYAK users for flights from Boston to Kos are SWISS and Lufthansa. With an average price for the route of $1,111 and an overall rating of 7.6, SWISS is the most popular choice. Lufthansa is also a great choice for the route, with an average price of $1,262 and an overall rating of 6.8.

  • How does KAYAK find such low prices on flights from Boston to Kos?

    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 Boston to Kos.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Kos from Boston 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 Boston to Kos?

    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 Kos with an airline and back to Boston with another airline. Booking your flights between Boston and KGS can sometimes prove cheaper using this method.

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

    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 Kos from Boston up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top airlines flying from Boston to Kos

 
See real verified KAYAK customer reviews for airlines flying from Boston to Kos. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Boston to Kos? 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.
7.6
SWISSOverall score based on 1861 reviews
7.4Comfort
8.3Crew
7.7Boarding
6.8Entertainment
7.1Food
Airline reviews

Bad experience overall. Crew did not provide food for our 2 year old (even though we specifically bought a child infant seat for her and literally bought another full price flight), which was unacceptable. And we had to pay $310 each way to carry our ski equipment even though they advertise it as something that is free. Tickets were purchased the same way as usual, but they told us we had Economy Light tickets (I never elected to have such seats). Just plain manipulation and false advertisment. Very disappointed overall about this airline.

2.0 MediocreAnonymous, Jan 2026
JFK - GVA
Read more SWISS reviews

Bad experience overall. Crew did not provide food for our 2 year old (even though we specifically bought a child infant seat for her and literally bought another full price flight), which was unacceptable. And we had to pay $310 each way to carry our ski equipment even though they advertise it as something that is free. Tickets were purchased the same way as usual, but they told us we had Economy Light tickets (I never elected to have such seats). Just plain manipulation and false advertisment. Very disappointed overall about this airline.

The trip was great until my luggage was lost on transfer from United to Swiss. It took Swiss 3 days to get my luggage to me though it was located almost immediately.

Horrible!! The WiFi was not working, the food was awful

We’ve never been more uncomfortable on a flight than we have on this particular one. The seats in front of us reclined so far back that when the person reclined their seat of broccoli, it almost hit me in the face and left me with literally no room to move that said I had to recline my seed in which made the person behind me upset. It seemed like the seats also would recline without even pressing the button in the armrest and would unrecline as well for that same reason, and it also seemed that some seats reclined more than others. The bottom cushions of the seat were so thin that even after one hour of an 11 hour flight, our tailbones were so sore. It seemed like an overall old airplane. It also didn’t have individual air vents and it was extremely hot the entire flight. Several passengers were commenting on how hot it was. The breakfast was some kind of flavorless triangle, puffy egg, laying in a watery bed of steamed peppers and onions and spinach. It was not appetizing at all. The flight crew was extremely nice so that was a nice thing this flight attendant. They let us try different types of Swiss sodas, which was really nice and the dinner was actually delicious but still overall given the other considerations. It was pretty much a miserable flight without basic seat comfort.

0lane 2qs on tim3. Very bad food. No free wifi, only for texts. Entertainment poor and hard to access.

They lived up to the Swiss reputation of excellent operation in all aspects. Zurich is a great place to make connections to other parts of Europe.

Food used to be better and comfort was not attainable after 5 hours everything starts hurting.

Horrible flight. First delay in boarding of approximately 30 minutes. While in the plane, the flight attendants huddle and we get an announcement that the crew's legal time was exceeded, that they don't have replacement crew and that they will need to cancel the flight. One would think that they would know that their time was to be exceeded BEFORE boarding. Took for ever to deplane. Then we were told that flight would not be cancelled but gave us a departure time of 21.15, which of course was not fulfilled. Arrived in Valencia, luggage took 30 minutes to arrive. Absolutely unacceptable

horrible.. they cause such a problem and my daughter 14 years old was stranded in san francisco

I can’t even the whole trip was a catastrophe

Missed it by a couple minutes and couldn’t find an alternative flight so had to spend the night in DC and after much shuffling from 1 airline to another managed to get a United to Frankfurt.

There were only 2 toilets and one of them did not work in business class. We are not allowed to cross classes so had to wait in line to use the toilets!! The entertainment touch display was finicky and did not work all the time.

We missed our flight. There was not enough time built into the layover to get through immigration, customs, bagclaim, bag rechecking, and the long trip to another terminal and gate. Kayak really screwed up. We took the bus up to Wisconsin and then were picked up in Brookfield by private car. It was lucky we didnt miss the last bus out.

I tried both on line and by calling the Customer Service line to arrange for a special meal as i have food intolerances. I was under the impression from your service representative that I was successful. I was not. I cannot eat spicy foods and get very ill if i eat bell peppers. I could not eat either menu choice and no special meal was actually ordered. ( your representative tried to order it for a flight that did not have meal service!!! - found this out later). Your wonderful cabin crew managed to put together a fruit, salad, roll and cheese tray for me so I had something to eat. WHY WOULD YOU SERVE SPICY FOOD, WITH NO MILDER OPTION,ON AN INTERNATIONAL FLIGHT???

Crew was professional and great, flight was clean. However food was pathetic. I ordered a Hindu meal assuming no meat but they served chicken. Need to be very specific- Hindu meal should be categorize as Vegetarian - no meat or egg. Or it should be specific that we are serving meat.

Late flight Delays Poor service Poor staff Worst airline ever

Ground staff and cabin crew were excellent. Flight was perfectly on time. Zero issues.

Even after a delay, getting off the ground, thanks for keeping me safe, the airline made certain that my connecting flight was rebooked to get me to my final destination. It was actually rebooked twice, and my luggage still managed to meet me. The airline gave me a credit for food and beverage to be used at the airport vendors, regretfully, the credit did not transfer to my final boarding pass. Oh, well…

Trip was smooth, good drew, average meal, almost cold coffee. Excellent landing. Did not enjoy going down the stairs, walking to the gate, walking up the stairs, going a long walk to the exchange gate, and going down the stairs again to be bussed all the way where we originally landed to take our next flight! Over all an average experience. Thank you.

I booked extra leg room, due to seat neighbor i now consider extra shoulder and arm room as well. Seems like the seats shrink in width now The crew was very friendly and professional ( 100%). Food was good not great, breakfast was bad, a dry slice of bread would have been better. Facilities clean.

Everything you need to know for your flight from Boston to Kos

Information on your arrival and departure airports