Bernard Grüner (14 May 1888 – 21 February 1955) was Croatian Jewish composer, hazzan of the Dohány Street Synagogue and chief hazzan of the Jewish Community in Zagreb. Grüner was born in Sieniawa, Poland (then part of Austro-Hungarian Empire) on 14 May 1888. As a child, when he was nine years old, Grüner was known singer in the Budapest Jewish circles. He finished elementary school and three years of economic high school in Budapest, where he also attended Yeshiva. In Szatmár County he gained his orthodox rabbinical college degree. Grüner studied for hazzan with the Hungarian State Opera House scholarship. In 1913, his first hazzan position was in Nitra, Slovakia. From 1918 to 1923, Grüner served as hazzan at the Dohány Street Synagogue in Budapest. In Székesfehérvár, Hungary he served as