Kirnbach is a village in the municipality of Wolfach in the district of Ortenaukreis, Baden-Württemberg.

The name Kirnbach comes from the Middle High German word Kürn (= mill).

The village went by marriage to Duke Reinhold of Urslingen and, after his death, to the line of Geroldseck from Sulz.

From them Kirnbach and its entire superior district (Oberamt) of Hornberg went to the Kingdom of Württemberg.

Kirnbach has its own Evangelical church, because it belonged to Württemberg before the Grand Duchy of Baden was formed.