Are there nonstop flights from Bangkok (BKK) to Haiphong (HPH)?

No. The fastest connection is via Da Nang, about 2h 39m of total flying time.

What is the fastest connection from Bangkok (BKK) to Haiphong (HPH)?

via Da Nang ≈ 2h 39m, via Nanning ≈ 2h 47m, via Phu Quoc Island ≈ 3h 3m (estimated flying time, excluding layovers).

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

Suvarnabhumi Airport (BKK) to Cat Bi International Airport (HPH)・1,016 km

No nonstop flights. The fastest connection is via Da Nang (DAD), about 2h 39m of flying time (layover not included).

With milesANA 15,000 miles+ (via CAN)Economy, one way, estimate. Tap a connection for miles by cabin.

None.

8 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.