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Kos

$818+ Cheap flights from Boston (BOS) to Kos (KGS)

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 4/18. Fares are subject to change and may not be available on all flights or dates of travel.
BOS — KGS
Feb 25 — Mar 41
Wed 2/25
Wed 3/4
1 adult, Economy
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Cheap flight deals from Boston to Kos

Cheapest flights from Boston to Kos
Explore the most affordable flight options available from Boston to Kos. Find the lowest fares from popular airlines and budget airlines, with prices last updated on January 26, 2026.

This Mytrip deal was found by Cheapflights users on 1/25. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/1810:40 am
BOS
-
KGS
2 stops28h 05m
Multiple Airlines
Fri 5/110:25 pm
KGS
-
BOS
3 stops30h 02m
Multiple Airlines
Deal found 1/25$818
This AranGrant deal was found by Cheapflights users on 1/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure AranGrant is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/107:25 am
BOS
-
KGS
1 stop22h 55m
British Airways
Wed 8/269:45 pm
KGS
-
BOS
1 stop22h 00m
British Airways
Deal found 1/24$3,998
This American Airlines deal was found by Cheapflights users on 1/24. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/109:20 pm
BOS
-
KGS
2 stops40h 25m
Multiple Airlines
Wed 8/269:45 pm
KGS
-
BOS
3 stops32h 13m
Multiple Airlines
Deal found 1/24$6,755

Find flight deals from Boston to Kos

Discover tips and strategies to find the most affordable flight options for your journey from Boston (BOS) to Kos (KGS). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated January 26, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$818
(Mytrip)
Provider with most accurate pricing for Boston Logan Intl-Kos flight deals.
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Provider most trusted by Cheapflights users for Boston Logan Intl-Kos flights.
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From Boston Logan Intl to Kos
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Cheapflights Fare Finder

 
Customize your flight search to find flights from Boston to Kos that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated January 26, 2026.
Use the filters below to find and compare flights from Boston to Kos that are best for you.

Fly from

Boston

Fly to

Kos

Route

Depart

Return

Price

BostonKos

BOS - KGS

BOSKGS

Boston Logan Intl

Sat 4/18

10:40 am-9:45 pm

2 stops28h 05m

Kos

Fri 5/1

10:25 pm-9:27 pm

3 stops30h 02m

$818

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/25

  • Most accurate provider: When it comes to deals on Boston-Kos flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Boston-Kos flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Boston-Kos flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Boston-Kos flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Boston-Kos flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

Best time to book a flight from Boston to Kos

Have a flexible travel schedule? Discover the best time to fly to Kos from Boston with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Reviews of airlines servicing Kos

Get insights into the airlines that provide service to Kos. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Kos. Reviews last updated January 26, 2026.
Read reviews from past customers who have flown SWISS and Lufthansa from Boston to Kos. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
SWISS
7.6
Good
1,861 reviews

Entertainment

6.8

Comfort

7.4

Food

7.1

Boarding

7.7

Overall

7.6

Crew

8.3

Reviews

1 / 20
10.0
Excellent

Henriette,Dec 2025

ZRH - JNB

The flight was good but again my luggage was delayed. The 2nd time now. I know it us at the airlines fault but maybe there have to be more control on which luggage on on which plane. Especially if a flight has been delayed.
SWISS
7.6
Good
1,861 reviews
SWISS
7.6
Good
1,861 reviews

Entertainment

6.8

Comfort

7.4

Food

7.1

Boarding

7.7

Overall

7.6

Crew

8.3

Reviews

1 / 20
10.0
Excellent

Henriette,Dec 2025

ZRH - JNB

The flight was good but again my luggage was delayed. The 2nd time now. I know it us at the airlines fault but maybe there have to be more control on which luggage on on which plane. Especially if a flight has been delayed.
Lufthansa
6.8
Okay
7,747 reviews
SWISS
7.6
Good
1,861 reviews

Entertainment

6.8

Comfort

7.4

Food

7.1

Boarding

7.7

Overall

7.6

Crew

8.3

Reviews

1 / 20
10.0
Excellent

Henriette,Dec 2025

ZRH - JNB

The flight was good but again my luggage was delayed. The 2nd time now. I know it us at the airlines fault but maybe there have to be more control on which luggage on on which plane. Especially if a flight has been delayed.

Related info for your journey

Find useful and relevant information for your journey from Boston to Kos. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What are the cheapest airlines flying from Boston to Kos round-trip?

    Cheapflights users have booked flights from Boston to Kos round-trip from $954. Another airline that can offer you cheap pricing is Lufthansa.

  • Can I find deals for flights from Boston to Kos that include hotel bookings?

    Yes. In addition to deals on Boston to Kos flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Boston to Kos?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Boston to Kos.

  • Can I find deals for business class flights from Boston to Kos?

    Yes. Cheapflights offers flight deals from Boston to Kos by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

See more FAQs

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Top 2 airlines flying from Boston to Kos

Discover the top 2 airlines that operate flights from Boston to Kos. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated January 26, 2026.
AirlineCheapestAverageFlexibilityOn-time
SWISSCheapest$954Average$1,111FlexibilityNo cancel feeOn-time79%
LufthansaCheapest$999Average$1,262FlexibilityNo cancel feeOn-time76%

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