Are there nonstop flights from Pisa (PSA) to Kos (KGS)?

Yes. Ryanair fly this route. Flight time is about 2h 23m.

What is the fastest connection from Pisa (PSA) to Kos (KGS)?

via Bari ≈ 2h 54m, via Athens ≈ 2h 54m, via Rhodes ≈ 3h 7m (estimated flying time, excluding layovers).

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

Pisa International Airport (PSA) to Kos International Airport "Ippokratis" (KGS)・1,607 km

Nonstop flights available (1 airline). Flight time about 2h 23m. Nonstop return flights also operate.

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

15 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.