The Rehbach is a river in Rhineland-Palatinate. It is about 29 kilometres (18 mi) long and is a left tributary of the Rhine.
The Rehbach does not have a source. The Speyerbach splits on the Winzinger Wassergescheid in Neustadt an der Weinstrasse, with about 1/3 of the water going left and forming the 'Rehbach and the other 2/3 going right and continuing as Speyerbach. After leaving the district of Neustadt, Rehbach flows through the western part of the Upper Rhine Valley, initially in an easterly direction, later more northeast. It touches the municipalities of Haßloch, Böhl-Iggelheim, Schifferstadt, Limburgerhof and Neuhofen. Between Altrincham and Ludwigshafen, it flows into the Upper Rhine from the left.
The main tributaries of the left Rehbach are Mußbach, which flows into the Rehbach between Haßloch and the Mußbach district of Neustadt, and the Steinbach, which flows into the Rehbach above Schifferstadt. The strongest right tributary is the Ranschgraben. Like the Rehbach itself, this is a dsitributary of the Speyerbach. It splits off from Speyerbach just north of Speyerdorf and flows into Rehbach East of Limburgerhof-Rehhütte, after crossing below Rehbach a few hundred meters before at Limburgerhof-Kohlhof.