Oskar Gustav Rudolf Hergt (22 October 1869 in Naumburg – 9 May 1967 in Göttingen) was a German lawyer and nationalist politician, who served simultaneously as the minister of Justice and vice-chancellor from 28 January 1927 to 12 June 1928.

Hergt attended the prestigious Domgymnasium Naumburg before studying law at Würzburg, Munich and Berlin.

Hergt held various senior offices at the Prussian Ministry of Finance from 1904 to 1914.

His support for the Dawes Plan in 1924 was seen as a betrayal of the party's line and led to his replacement with the more hardline conservative Kuno von Westarp.

After the rise of the Nazi Party, Hergt retired from politics.