As the head of the Kriminalpolizei (criminal police) in Munich, Frick took part in Hitler's failed Beer Hall Putsch of 1923, for which he was convicted of high treason. He managed to avoid imprisonment and soon afterwards became a leading figure of the National Socialist Party (NSDAP) in the Reichstag. In 1930, Frick became the first National Socialist to hold a ministerial-level post at any level in Germany. He served in Thuringia as the state Minister of the Interior.

After Hitler became Chancellor of Germany in 1933, Frick joined the new government and was named Minister of the Interior. Additionally, on 21 May 1935, Frick was named Generalbevollmächtigter für die Reichsverwaltung (General Plenipotentiary for the Administration of the Reich). He was instrumental in formulating laws that consolidated the Nazi regime (Gleichschaltung), as well as laws that defined the Nazi racial policy, most notoriously the Nuremberg Laws. On 30 August 1939, immediately prior to the outbreak of WW2, Frick was appointed by Hitler to the six-person Council of Ministers for Defense of the Reich which operated as a war cabinet. Following the rise of the SS, Frick gradually lost favour within the party, and in 1943 he was replaced by Heinrich Himmler as interior minister. Frick remained in the cabinet as a minister without portfolio until Hitler's death in 1945.