Klara was born in the Austrian village of Spital, Weitra, Lower Austria. Her father was Johann Baptist Pölzl and her mother was Johanna Hiedler. Either Hiedler's father, Johann Nepomuk Hiedler, or his brother, Johann Georg Hiedler, was the biological father of Alois Hitler, the man she would later marry. It is presumed and accepted by most that the father was Johann Georg Hiedler. Klara and Alois were first cousins once removed.