Are there nonstop flights from Washington (IAD) to Osaka (KIX)?

No. The fastest connection is via Toronto, about 14h 10m of total flying time.

What is the fastest connection from Washington (IAD) to Osaka (KIX)?

via Toronto ≈ 14h 10m, via Tokyo ≈ 14h 19m, via Vancouver ≈ 14h 46m (estimated flying time, excluding layovers).

from 20,000 ANA miles, from 45,000 JAL miles (economy, one way, based on the published award charts).

Washington Dulles International Airport (IAD) to Kansai International Airport (KIX)・11,190 km

No nonstop flights. The fastest connection is via Toronto (YYZ), about 14h 10m of flying time (layover not included).

With milesANA 20,000 miles+ (via HND)JAL 45,000 miles+ (via ICN)Economy, one way, estimate. Tap a connection for miles by cabin.

None.

16 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.