Are there nonstop flights from Kos (KGS) to Washington (IAD)?

No. The fastest connection is via Geneva, about 11h 6m of total flying time.

What is the fastest connection from Kos (KGS) to Washington (IAD)?

via Geneva ≈ 11h 6m, via Venice ≈ 11h 6m, via Zurich ≈ 11h 7m (estimated flying time, excluding layovers).

from 27,500 ANA miles (economy, one way, based on the published award charts).

Kos International Airport "Ippokratis" (KGS) to Washington Dulles International Airport (IAD)・8,594 km

No nonstop flights. The fastest connection is via Geneva (GVA), about 11h 6m of flying time (layover not included).

With milesANA 27,500 miles+ (via GVA)Economy, one way, estimate. Tap a connection for miles by cabin.

None.

14 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.