BOS - KGS

$949 Find Cheap Flights from Boston to Kos - Compare and Save

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 8/11. 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
$949
SWISS
Tue 8/11Thu 8/20
BOS - KGS • 1 stop
Cheapest one-way
$996
Multiple Airlines
Sun 7/5
BOS - KGS • 2 stops
Top airlines
Cheapest • from $949 (round-trip)
Best reviews • 7.5 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
Nonstop flights
Not available
There are currently no direct flights between Boston and Kos. You'll need at least 1 connection.
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We hope you love your trip to Kos!
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

Tue, Aug 11 - Thu, Aug 20
SWISS Logo
9:40 pm - 7:55 pm
BOS
-
KGS
15h 15m
1 stop
SWISS Logo
11:00 am - 7:55 pm
KGS
-
BOS
15h 55m
1 stop
$949SWISS
Tue, Aug 11 - Thu, Aug 20
Multiple Airlines Logo
7:23 pm - 7:05 pm
BOS
-
KGS
16h 42m
2 stops
Multiple Airlines Logo
11:00 am - 7:55 pm
KGS
-
BOS
15h 55m
1 stop
$1,009Multiple Airlines
Fri, Jul 31 - Mon, Aug 31
Multiple Airlines Logo
8:05 pm - 7:45 pm
BOS
-
KGS
16h 40m
1 stop
Multiple Airlines Logo
11:00 am - 3:10 pm
KGS
-
BOS
35h 10m
1 stop
$1,075Multiple Airlines
Tue, Aug 11 - Thu, Aug 20
Multiple Airlines Logo
4:45 pm - 10:10 am
BOS
-
KGS
34h 25m
3 stops
Multiple Airlines Logo
11:00 am - 2:45 pm
KGS
-
BOS
34h 45m
3 stops
$1,083Multiple Airlines
Fri, Jul 31 - Mon, Aug 31
Lufthansa Logo
8:05 pm - 7:45 pm
BOS
-
KGS
16h 40m
1 stop
Lufthansa Logo
12:40 pm - 11:59 pm
KGS
-
BOS
18h 19m
2 stops
$1,118Lufthansa
Tue, Aug 11 - Wed, Aug 19
Multiple Airlines Logo
10:50 am - 12:35 am
BOS
-
KGS
30h 45m
3 stops
Multiple Airlines Logo
12:50 am - 6:50 pm
KGS
-
BOS
25h 00m
2 stops
$1,141Multiple Airlines
Tue, Aug 11 - Thu, Aug 20
Multiple Airlines Logo
8:50 pm - 10:45 pm
BOS
-
KGS
18h 55m
2 stops
Multiple Airlines Logo
12:10 pm - 9:45 pm
KGS
-
BOS
16h 35m
2 stops
$1,145Multiple Airlines
Fri, Jul 31 - Mon, Aug 31
Multiple Airlines Logo
10:00 pm - 7:45 pm
BOS
-
KGS
14h 45m
2 stops
Multiple Airlines Logo
12:40 pm - 9:27 pm
KGS
-
BOS
15h 47m
2 stops
$1,171Multiple Airlines
Fri, Jul 31 - Mon, Aug 31
Multiple Airlines Logo
10:40 am - 7:10 pm
BOS
-
KGS
25h 30m
3 stops
Multiple Airlines Logo
6:10 pm - 8:20 pm
KGS
-
BOS
33h 10m
3 stops
$1,187Multiple Airlines
Fri, Jul 31 - Mon, Aug 31
Multiple Airlines Logo
10:05 am - 7:10 pm
BOS
-
KGS
26h 05m
2 stops
Multiple Airlines Logo
6:10 pm - 8:20 pm
KGS
-
BOS
33h 10m
3 stops
$1,195Multiple 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.

Which airlines provide the cheapest flights from Boston to Kos?

The cheapest round-trip price for the route for each airline clicked by KAYAK users in the last 5 days.

In the past 5 days, the cheapest round-trip tickets from Boston to Kos were found on SWISS ($949) and Lufthansa ($1,118).

Good to know

Cheapest flight$949
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 5 days, the lowest price for a flight from Boston to Kos was $996 for a one-way ticket and $949 for a round-trip.

  • 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.

  • 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 airline 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.
7.5
SWISSOverall score based on 1971 reviews
7.7Boarding
6.8Entertainment
7.4Comfort
8.3Crew
7.1Food
Airline reviews

On time arrivals and departure, good in flight entertainment, courteous flight attendants, decent meals, reasonable seat space

10.0 ExcellentAnonymous, Jun 2026
ZRH - DEL
Read more SWISS reviews

On time arrivals and departure, good in flight entertainment, courteous flight attendants, decent meals, reasonable seat space

Didn't make the connection as my primary flight was 3 hrs late, I had to basically beg to be put on a different airline to continue my trip otherwise I would have been sitting on the airport for 8 hrs

3hr delay and then missed connecting flight with another 6hr wait at the airport before getting a continuation to my trip, worst trip ever in my 50+years of flight travel

Without a doubt, my “customer service” experience with SWISS was the worst of my life. Multiple disconnections in conversations, very cold and indifferent staff, failure to follow up with promised status updates — simply put, T. H. E. W. O. R. S. T. A full week later, and I am STILL waiting to hear from them. Never again for me with SWISS. Disgraceful.

The flight and all amenities were good to excellent. SWISS was awful to deal with. Every step of the way they nickel and dime you. Chose your seats? $14. Change your seats… No accounting for the prior payment. You get billed again. 17 pound restriction on overhead luggage, nonsense. It’s a weight in the plane whether it’s in the overhead or in check baggage. They just milk you for every cent they can and I resent it. The flight was excellent.

plenty of legspace, snacks, no pull face from flight attendants when asking for a wine. Also fast transfer ability at ZRH.

The flight itself was fine, but due to a snow delay my connection to Lisbon was delayed by six hours. Despite this, Swiss Air still managed to lose my luggage. Not acceptable. Someone else on the flight also lost their luggage.

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

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

Information on your arrival and departure airports