Are there nonstop flights from Sapporo (CTS) to Haikou (HAK)?

No. The fastest connection is via Busan, about 5h 33m of total flying time.

What is the fastest connection from Sapporo (CTS) to Haikou (HAK)?

via Busan ≈ 5h 33m, via Shanghai ≈ 5h 33m, via Hong Kong ≈ 5h 33m (estimated flying time, excluding layovers).

from 23,000 JAL miles (economy, one way, based on the published award charts).

New Chitose Airport (CTS) to Haikou Meilan International Airport (HAK)・3,865 km

No nonstop flights. The fastest connection is via Busan (PUS), about 5h 33m of flying time (layover not included).

With milesJAL 23,000 miles+ (via PVG)Economy, one way, estimate. Tap a connection for miles by cabin.

None.

10 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.