Are there nonstop flights from Singapore (SIN) to Seoul (GMP)?

No. The fastest connection is via Kaohsiung, about 6h 33m of total flying time.

What is the fastest connection from Singapore (SIN) to Seoul (GMP)?

via Kaohsiung ≈ 6h 33m, via Jeju City ≈ 6h 34m, via Busan ≈ 6h 45m (estimated flying time, excluding layovers).

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

Singapore Changi Airport (SIN) to Seoul Gimpo International Airport (GMP)・4,653 km

No nonstop flights. The fastest connection is via Kaohsiung (KHH), about 6h 33m of flying time (layover not included).

With milesANA 18,500 miles+ (via PEK)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.