Are there nonstop flights from Gorgan (GBT) to Tehran (THR)?

Yes. Iran Air, Iran Aseman Airlines, Qeshm Air, Pars Air, Kish Air, Pouya Air, List of airlines of Iran fly this route. Flight time is about 52m.

Gorgan → Tehran

Gorgan Airport (GBT) to Mehrabad International Airport (THR)・308 km

Nonstop flights available (7 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.