For the town in Baden-Württemberg, see Murg, Germany.

The Murg is a right tributary of the Rhine, located in Baden-Württemberg, Germany. It rises in the Black Forest, in Obertal, a constituent community (Ortsteil) of Baiersbronn, where the rivers Rechtmurg (right Murg) and Rotmurg (red Murg), both rising on the Schliffkopf in Baiersbronn, join.

Downstream from Obertal, it flows through Baiersbronn, Forbach, Gernsbach, and Gaggenau before reaching the Rhine at Rastatt. Its length is 96 km; its drainage basin has a size of 637 km². Its mouth was shifted 1.5 km to the west by the straightening of the Rhine by engineer Johann Gottfried Tulla. In the past the Murg was of importance for timber rafting. Wood was rafted as far as Steinmauern, where it was dried and combined into bigger rafts. From Steinmauern the rafts where floated down to Mannheim, and from there to the Netherlands.