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Cheap flights from Boston to Kos from $337

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Boston to Kos departing on 9/7. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
0 bags

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Find the cheapest flights from Boston to Kos

Cheap round-trip flights

Enter your travel dates to find the best prices.
SWISS Logo
5:20 pm - 7:55 pm
BOS
-
KGS
19h 35m
1 stop
SWISS Logo
8:30 pm - 7:55 pm
KGS
-
BOS
30h 25m
1 stop
$973SWISS
Tue, Sep 8 - Tue, Sep 15
Multiple Airlines Logo
5:10 pm - 8:20 pm
BOS
-
KGS
20h 10m
1 stop
Multiple Airlines Logo
11:00 am - 3:10 pm
KGS
-
BOS
35h 10m
1 stop
$980Multiple Airlines
Wed, Sep 9 - Thu, Oct 1
Austrian Airlines Logo
5:10 pm - 8:20 pm
BOS
-
KGS
20h 10m
1 stop
Austrian Airlines Logo
9:40 pm - 1:50 pm
KGS
-
BOS
23h 10m
1 stop
$982Austrian Airlines
Wed, Sep 9 - Wed, Sep 16
Austrian Airlines Logo
12:34 pm - 8:20 pm
BOS
-
KGS
24h 46m
2 stops
Austrian Airlines Logo
9:40 pm - 1:50 pm
KGS
-
BOS
23h 10m
1 stop
$987Austrian Airlines
Wed, Sep 9 - Wed, Sep 16
Lufthansa Logo
8:05 pm - 7:05 pm
BOS
-
KGS
16h 00m
1 stop
Lufthansa Logo
9:45 am - 11:54 pm
KGS
-
BOS
45h 09m
2 stops
$1,020Lufthansa
Tue, Sep 8 - Mon, Sep 14
Lufthansa Logo
8:05 pm - 7:05 pm
BOS
-
KGS
16h 00m
1 stop
Lufthansa Logo
7:55 pm - 8:10 pm
KGS
-
BOS
31h 15m
2 stops
$1,023Lufthansa
Tue, Sep 8 - Wed, Sep 30
SWISS Logo
9:40 pm - 8:00 pm
BOS
-
KGS
15h 20m
1 stop
SWISS Logo
11:00 am - 3:10 pm
KGS
-
BOS
35h 10m
1 stop
$1,033SWISS
Fri, Sep 11 - Mon, Sep 14
Austrian Airlines Logo
5:10 pm - 8:50 pm
BOS
-
KGS
20h 40m
1 stop
Austrian Airlines Logo
8:50 pm - 1:50 pm
KGS
-
BOS
24h 00m
1 stop
$1,042Austrian Airlines
Thu, Sep 10 - Mon, Sep 14
Austrian Airlines Logo
12:34 pm - 8:20 pm
BOS
-
KGS
24h 46m
2 stops
Austrian Airlines Logo
9:40 pm - 1:50 pm
KGS
-
BOS
23h 10m
1 stop
$1,047Austrian Airlines
Wed, Sep 9 - Fri, Sep 18
Lufthansa Logo
8:05 pm - 7:05 pm
BOS
-
KGS
16h 00m
1 stop
Lufthansa Logo
9:40 am - 3:40 pm
KGS
-
BOS
13h 00m
1 stop
$1,049Lufthansa
Tue, Sep 8 - Sat, Oct 3

SWISS flights from Boston to Kos

Our best SWISS deals on Boston to Kos flight tickets
SWISS
Sep 8
BOS5:20 pmBoston Logan Intl
19h 35m
1 stop
KGS7:55 pmKos
Sep 15
KGS8:30 pmKos
30h 25m
1 stop
BOS7:55 pmBoston Logan Intl
$973
SWISS
Sep 11
BOS9:40 pmBoston Logan Intl
15h 20m
1 stop
KGS8:00 pmKos
Sep 14
KGS11:00 amKos
35h 10m
1 stop
BOS3:10 pmBoston Logan Intl
$1,033
SWISS
Sep 11
BOS9:40 pmBoston Logan Intl
15h 20m
1 stop
KGS8:00 pmKos
Sep 18
KGS3:55 pmKos
30h 15m
1 stop
BOS3:10 pmBoston Logan Intl
$1,093

Austrian Airlines flights from Boston to Kos

Our best Austrian Airlines deals on Boston to Kos flight tickets
Austrian Airlines
Sep 9
BOS5:10 pmBoston Logan Intl
20h 10m
1 stop
KGS8:20 pmKos
Sep 16
KGS9:40 pmKos
23h 10m
1 stop
BOS1:50 pmBoston Logan Intl
$982
Austrian Airlines
Sep 9
BOS12:34 pmBoston Logan Intl
24h 46m
2 stops
KGS8:20 pmKos
Sep 16
KGS9:40 pmKos
23h 10m
1 stop
BOS1:50 pmBoston Logan Intl
$987
Austrian Airlines
Sep 10
BOS5:10 pmBoston Logan Intl
20h 40m
1 stop
KGS8:50 pmKos
Sep 14
KGS8:50 pmKos
24h 00m
1 stop
BOS1:50 pmBoston Logan Intl
$1,042

momondo 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, momondo users made 832,500 searches. Data last updated May 8, 2026.
Use the filters below to find and compare flights from Boston to Kos that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

BostonKos

BOS - KGS

BOSKGS

Boston Logan Intl

Tue 9/8

5:20 pm-7:55 pm

1 stop19h 35m

Kos

Tue 9/15

8:30 pm-7:55 pm

1 stop30h 25m

$973

BostonKos

BOS - KGS

BOSKGS

Boston Logan Intl

Wed 9/9

5:10 pm-8:20 pm

1 stop20h 10m

Kos

Thu 10/1

11:00 am-3:10 pm

1 stop35h 10m

$980

BostonKos

BOS - KGS

BOSKGS

Boston Logan Intl

Wed 9/9

5:10 pm-8:20 pm

1 stop20h 10m

Kos

Wed 9/16

9:40 pm-1:50 pm

1 stop23h 10m

$982

BostonKos

BOS - KGS

BOSKGS

Boston Logan Intl

Wed 9/9

12:34 pm-8:20 pm

2 stops24h 46m

Kos

Wed 9/16

9:40 pm-1:50 pm

1 stop23h 10m

$987

BostonKos

BOS - KGS

BOSKGS

Boston Logan Intl

Tue 9/8

8:05 pm-7:05 pm

1 stop16h 00m

Kos

Mon 9/14

9:45 am-11:54 pm

2 stops45h 09m

$1,020

BostonKos

BOS - KGS

BOSKGS

Boston Logan Intl

Tue 9/8

8:05 pm-7:05 pm

1 stop16h 00m

Kos

Wed 9/30

7:55 pm-8:10 pm

2 stops31h 15m

$1,023

BostonKos

BOS - KGS

BOSKGS

Boston Logan Intl

Fri 9/11

9:40 pm-8:00 pm

1 stop15h 20m

Kos

Mon 9/14

11:00 am-3:10 pm

1 stop35h 10m

$1,033

BostonKos

BOS - KGS

BOSKGS

Boston Logan Intl

Thu 9/10

5:10 pm-8:50 pm

1 stop20h 40m

Kos

Mon 9/14

8:50 pm-1:50 pm

1 stop24h 00m

$1,042

BostonKos

BOS - KGS

BOSKGS

Boston Logan Intl

Wed 9/9

12:34 pm-8:20 pm

2 stops24h 46m

Kos

Fri 9/18

9:40 pm-1:50 pm

1 stop23h 10m

$1,047
Quickest round-trip

BostonKos

BOS - KGS

BOSKGS

Boston Logan Intl

Tue 9/8

8:05 pm-7:05 pm

1 stop16h 00m

Kos

Sat 10/3

9:40 am-3:40 pm

1 stop13h 00m

$1,049

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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2

See travel insights to Kos from

How to get the cheapest flight ticket from Boston to Kos

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest airline that flies from Boston Logan Intl to Kos?

Lufthansa and Brussels Airlines are the most popular carriers operating from Boston Logan Intl to Kos

When to book flights from Boston to Kos

Are you open to changing your travel dates? Check out the ideal times to fly from Boston to Kos according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Boston to Kos (BOS to KGS) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Boston to Kos

Fastest flight time

16h 00m

Direct flights

None
The fastest flight from Boston to Kos takes 16h 00m
There are no direct flights from Boston to Kos. There are no popular flight routes from Boston to Kos.
Search flight deals

Frequently asked questions about flying from Boston to Kos

  • How far is Boston Logan Intl to Kos by plane?

    The distance between Boston Logan Intl and Kos is about 4930.9 mi. By plane, this route typically takes 16h 00m.

  • When did momondo last update prices for flights from Boston Logan Intl Airport to Kos Airport?

    Prices for flights from Boston Logan Intl Airport to Kos Airport are refreshed on a daily basis.

  • How old do you have to be to fly from Boston Logan Intl Airport to Kos Airport?

    The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Boston Logan Intl Airport to Kos Airport.

  • What documentation or ID do you need to fly to Kos Airport?

    The necessary travel and health documents for your Kos Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

Traveling to a place near Kos?

Book flights to Kos if you plan to visit one of these locations
Kardamena
Marmari

Why use momondo?

Why should I use momondo to find a flight deal from Boston to Kos?

To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to Kos from Boston.

Can I find flights from Boston to Kos with flexible booking policies on momondo?

Yes. momondo enables you to select and highlight flights to Kos from Boston with this policy.

How can momondo help me find flights from Boston to Kos?

momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from Boston to Kos.

I’m not ready to book a flight from Boston to Kos right now. Can momondo alert me if prices change?

If you are not ready to book a flight from Boston to Kos now, use our insights above to find helpful tips or alternatively set up a price alert, where momondo will track prices on flights to Kos and let you know when they change.

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