Are there nonstop flights from Kolkata (CCU) to Guangzhou (CAN)?

Yes. IndiGo fly this route. Flight time is about 3h 29m.

What is the fastest connection from Kolkata (CCU) to Guangzhou (CAN)?

via Kunming ≈ 4h 1m, via Dhaka ≈ 4h 2m, via Hanoi ≈ 4h 4m (estimated flying time, excluding layovers).

from 15,000 JAL miles, from 18,000 ANA miles (economy, one way, based on the published award charts).

Netaji Subhash Chandra Bose International Airport (CCU) to Guangzhou Baiyun International Airport (CAN)・2,541 km

Nonstop flights available (1 airline). Flight time about 3h 29m. Nonstop return flights also operate.

With milesJAL 15,000 miles+ (via KMG)ANA 18,000 miles+ (via BKK)Economy, one way, estimate. Tap a connection for miles by cabin.

13 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.