Theodor Freiherr von Sass (18 August 1881 – 9 August 1958), also spelled Saß, was a German Lutheran pastor and community leader in Memelland, a central figure in a legal process known as the Trial of Neumann and Sass. Sentenced in 1935 to sixteen years’ imprisonment for treason against Lithuania, he was pardoned in 1937 and became a pastor in Wismar in Mecklenburg.