Both of Riesser's grandfathers were rabbis; his paternal grandfather was Jakob Pinchas Katzenellenbogen, rabbi in Lemberg and later Oettingen, and his maternal grandfather was Raphael Cohen, Chief Rabbi of Altona-Hamburg-Wandsbek from 1775. Yet his father, having changed the family name from Katzenellenbogen to Riesser, chose to work as a secretary at the Jewish law court of Altona before he finally became a merchant in Hamburg. After his education at the renowned grammar school Johanneum, Gabriel Riesser went to Heidelberg and Kiel, where he studied law from 1824 to 1828, writing his doctorate dissertation in Heidelberg. He became a leading advocate of Jewish emancipation. He had himself suffered discrimination because of his religion: in Heidelberg and Jena he was denied the position of a university lecturer, in Hamburg in 1829 he was not allowed to practice as a lawyer. In his application he had recurred to a privilege of equal treatment that had been granted during the French occupation. His application, however, was refused because he formally was no citizen (which he as a Jew could not become) of the city of Hamburg.