Freital is located southwest of Dresden in the Döhlen Basin, through which the Weißeritz flows from south-west to north-east. The Windberg hill, is the town's local mountain and well-known landmark, rising about 100 metres (330 ft) above the valley floor. The lowest part of the town is the point where the Weißeritz enters the territory of the city of Dresden (about 195 metres (640 ft) above sea level).

The two rivers, the Red Weißeritz and Wild Weißeritz, merge in Hainsberg, a district of Freital. Other tributaries of the combined Weißeritz in the Freital area are the Wiederitz, Poisenbach and smaller, mainly canalized streams like the Vorholzbach, Burgker Bach, the Birkigter Bach, the Somsdorfer Bach and the Weißiger Bach. There are no natural lakes; the tailing pond near the slag heap and the Zauckerode retention basin were both constructed in the 20th century.

Geologically, the Döhlen Basin is a Rotliegendes depression that was formed at the end of the Carboniferous period. It is located between the Elbe Valley zone and the Ore Mountain gneiss massif.