Proleb is a municipality in the district of Leoben in the Austrian state of Styria. It lies in the northern part of the Upper Mur valley, between the towns of Leoben and Sankt Dionysen.
The municipal area includes the valleys of three streams — the Prentgrabenbach, the Prolebbach and the Kletschbach — while the river Mur forms its southern border. The village valley sits at about 500 metres above sea level.
Proleb's territory is mostly wooded and rises to over 1,400 metres above sea level at the Klatschbachkogel.