Friedrich Karl Hermann Entress (8 December 1914 – 28 May 1947) was a German camp doctor in various concentration and extermination camps during the Second World War. He conducted human medical experimentation at Auschwitz and introduced the procedure there of injecting lethal doses of phenol directly into the hearts of prisoners. He was captured by the Allies in 1945, sentenced to death at the Mauthausen-Gusen camp trials, and executed in 1947.