On 5 May 1933 Sprenger was appointed Reichsstatthalter of Hesse and leader (Gauleiter) of the new Gau formed from the Prussian province of Hesse-Nassau, which included the federated state of Hesse-Darmstadt. In the process of the Gleichschaltung, in particular due to the 'Reichsstatthaltergesetz' of 30 January 1935, he was able to take over leadership of the provincial government from Philipp Wilhelm Jung. Besides Martin Mutschmann of Saxony, he was the only governor charged with such a double function.