Vrontous (Greek: Βροντούς, Bulgarian: Шарлия - Sharliya) is a mountain range in the northeastern Serres and the westernmost Drama regional units in Greece.

Its highest peak is the Ali Babas (Greek: Αλή Μπαμπάς) at 1,849 m elevation.

It stretches between the village Vamvakofyto in the southwest and Perithori in the northeast, over a length of about 35 km.

The Greek National Road 63/E79 (Serres - Sidirokastro - Promachonas - Bulgaria) passes west of the mountains.

The mountains were rich in minerals (silver and iron), which took advantage of the people from ancient to modern times.