Are there nonstop flights from Rome (FCO) to Osijek (OSI)?

No. The fastest connection is via Zadar, about 1h 47m of total flying time.

What is the fastest connection from Rome (FCO) to Osijek (OSI)?

via Zadar ≈ 1h 47m, via Split ≈ 1h 48m, via Zagreb ≈ 1h 53m (estimated flying time, excluding layovers).

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

Rome–Fiumicino Leonardo da Vinci International Airport (FCO) to Osijek Airport (OSI)・666 km

No nonstop flights. The fastest connection is via Zadar (ZAD), about 1h 47m of flying time (layover not included).

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

None.

5 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.