Gustav Hölzel (2 September 1813 – 3 December 1883) was an Austro-Hungarian bass-baritone and composer who sang in the opera-houses of Austria, Germany and elsewhere for nearly fifty years. He is principally remembered as the first Beckmesser in Richard Wagner's Die Meistersinger von Nürnberg.
He was born in Pest, Hungary, the son of the actor, singer and theatre director Nikolaus Alois Hölzel (1785–1848) who managed the Landestheater in Linz, 1819–24. His mother Elisabeth Hölzel (née Umlauf) was an operatic contralto, daughter of composer Ignaz Umlauf, and sister of composer Michael Umlauf. At the age of sixteen, Gustav made his operatic debut in Sopron, and his career continued in Graz (1830–1832), the Theater in der Josefstadt in Vienna (1833–1837), and the Königstädtischen Theater in Berlin (1837–1838). He pursued further training in Paris in 1838 before joining the Stadttheater Zurich where he was committed from 1838-1840. In 1840, he joined the Hofoper at the Theater am Kärntnertor in Vienna.
Hölzel sang at the Hofoper for twenty-three years, during which he created the small role of De Fiesque in Gaetano Donizetti's opera Maria di Rohan in 1843. But in 1863, while playing the role of Friar Tuck in Heinrich Marschner's Der Templer und die Jüdin, Hölzel altered the words of the Friar's song and was dismissed from the company.