Henry IX, Count of Schwarzburg-Blankenburg

Henry IX (XII), called the Younger (c. 1325–1372/73), was the elder son of Count Henry VII (X) of Schwarzburg-Blankenburg and Elisabeth of Weimar-Orlamünde. In 1338 he married Agnes of Hohnstein-Sondershausen.

He later held a cluster of Schwarzburg lordships: Schlotheim, Rudolstadt, Frankenhausen, half of Arnstadt, Blankenburg, Saalfeld, Sondershausen and Ehrenstein. He sat as imperial judge in 1363–1365 and served as captain of the Altmark in 1366, and died between 1372 and 1373.