Heinrich Lammasch (21 May 1853 – 6 January 1920) was an Austrian jurist.
He was a professor of criminal and international law, a member of the Hague Arbitration Tribunal, and served as the last Minister-President of Austria (or Cisleithania) for a few weeks in October and November 1918.
He was the first and only non-noble to serve as Minister-President in the Austrian half of the Habsburg Monarchy.