Gradac sits on the main coastal road (Route D8) between Split and Dubrovnik, roughly 90 kilometres from Split and 85 kilometres from Dubrovnik. Buses on the Split–Dubrovnik route stop in Gradac several times daily; the journey from Split takes about two hours.
If you are driving, the coastal road is scenic but slow and winding in places — allow extra time. There is no train service. In summer, ferries from Trpanj on the Pelješac peninsula across the channel connect to Ploče, the nearest town with better transport links, though this is more useful for regional travel than for arriving at Gradac itself.