Are there nonstop flights from Bucharest (OTP) to Santander (SDR)?

Yes. Wizz Air fly this route. Flight time is about 3h 18m.

What is the fastest connection from Bucharest (OTP) to Santander (SDR)?

via Treviso ≈ 3h 48m, via Milan ≈ 3h 48m, via Bologna ≈ 3h 49m (estimated flying time, excluding layovers).

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

Bucharest Henri Coandă International Airport (OTP) to Seve Ballesteros-Santander Airport (SDR)・2,383 km

Nonstop flights available (1 airline). Flight time about 3h 18m. Nonstop return flights also operate.

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

21 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.