Are there nonstop flights from Hanoi (HAN) to Busan (PUS)?

Yes. VietJet Air, Vietnam Airlines fly this route. Flight time is about 3h 43m.

What is the fastest connection from Hanoi (HAN) to Busan (PUS)?

via Hangzhou ≈ 4h 13m, via Shanghai ≈ 4h 14m, via Nanjing ≈ 4h 14m (estimated flying time, excluding layovers).

from 15,000 JAL miles, from 18,500 ANA miles (economy, one way, based on the published award charts).

Noi Bai International Airport (HAN) to Gimhae International Airport (PUS)・2,736 km

Nonstop flights available (2 airlines). Flight time about 3h 43m. Nonstop return flights also operate.

With milesJAL 15,000 miles+ (via PVG)ANA 18,500 miles+ (via TPE)Economy, one way, estimate. Tap a connection for miles by cabin.

30 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.