The trial of Neumann and Sass (Lithuanian: Noimano-Zaso teismo procesas; German: Neumann-Sass-Kriegsgerichtsprozess) was the first and largest mass trial of Nazis in the early 1930s. The trial resulted in the convictions of the leaders of regional Nazi parties, Theodor von Sass, and other party members for their activity in the Klaipėda Region.