Are there nonstop flights from Kos (KGS) to Barcelona (BCN)?

No. The fastest connection is via Athens, about 3h 36m of total flying time.

What is the fastest connection from Kos (KGS) to Barcelona (BCN)?

via Athens ≈ 3h 36m, via Naples ≈ 3h 36m, via Rome ≈ 3h 38m (estimated flying time, excluding layovers).

from 15,000 ANA miles (economy, one way, based on the published award charts).

Kos International Airport "Ippokratis" (KGS) to Josep Tarradellas Barcelona-El Prat Airport (BCN)・2,209 km

No nonstop flights. The fastest connection is via Athens (ATH), about 3h 36m of flying time (layover not included).

With milesANA 15,000 miles+ (via ATH)Economy, one way, estimate. Tap a connection for miles by cabin.

None.

56 one-stop options, sorted by estimated flying time. Tap one to see the airlines on each leg and booking links.

Times are estimated from distance. Check schedules, frequency and availability with the airline or a booking site.