The Schmiddis (also: Schmiddisbach) is one of the headstreams of the river Haslach. It is situated in the region of Upper Swabia in Baden Württemberg, Germany.
The Schmiddis is a small stream which has its source in the hamlet of Schmiddis near Treherz, part of the municipality of Aitrach in the district of Ravensburg. It runs in a northerly direction for 3 kilometres, It joins the Rappenbach at the retention basin Rappenbach, forming the river Haslach.
Two bridges cross the Schmiddis, one for the state road 314, and a second one close to the mouth of the stream near the retention basin Rappenbach.