Are there nonstop flights from Phnom Penh (KTI) to Beijing (PKX)?

Yes. Cambodia Airways fly this route. Flight time is about 4h 25m.

What is the fastest connection from Phnom Penh (KTI) to Beijing (PKX)?

via Nanning ≈ 4h 56m, via Changsha ≈ 4h 56m, via Wuhan ≈ 4h 57m (estimated flying time, excluding layovers).

from 18,000 ANA miles, from 23,000 JAL miles (economy, one way, based on the published award charts).

Techo International Airport (KTI) to Beijing Daxing International Airport (PKX)・3,328 km

Nonstop flights available (1 airline). Flight time about 4h 25m. Nonstop return flights also operate.

With milesANA 18,000 miles+ (via SZX)JAL 23,000 miles+ (via WUH)Economy, one way, estimate. Tap a connection for miles by cabin.

26 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.