Are there nonstop flights from Tripoli (MJI) to Sfax (SFA)?

Yes. Afriqiyah Airways, Libyan Airlines fly this route. Flight time is about 52m.

Tripoli → Sfax

Mitiga International Airport (MJI) to Sfax Thyna International Airport (SFA)・314 km

Nonstop flights available (2 airlines). Flight time about 52m. Nonstop return flights also operate.

Times are estimated from distance. Check schedules, frequency and availability with the airline or a booking site.