Erich Sack (1 April 1887 – 24 January 1943) was a German Lutheran Pastor and resistance fighter against the Nazis.Sack was born in Goldap, East Prussia (today Gołdap, Poland) and studied Lutheran theology at the University of Königsberg. He started to work as a Pastor at the Parish of St. Anschar and the „Bethlehem”-hospital in Eppendorf, Hamburg. In 1914 he returned to East Prussia and became a Pastor with the Evangelical State Church of Prussia's older Provinces in Lyck (Ełk).