Johann Niemann (4 August 1913 – 14 October 1943) was a German SS officer and Holocaust perpetrator who was deputy commandant of Sobibor extermination camp during Operation Reinhard.

He also served as a Leichenverbrenner (corpse cremator) at Grafeneck, Brandenburg, and Bernburg during the Aktion T4, the SS "euthanasia" program.

He ordered the seventy-two Jews to be executed.On 14 October 1943, a prisoner uprising took place at the Sobibor extermination camp.

Niemann was the highest-ranking SS officer who was on duty that day, and so he was the first person targeted to be assassinated by the prisoners.

During an appointment to be fitted for a leather jacket taken from a murdered Jew, Niemann was killed in the tailor's barracks with an axe to his head by Alexander Shubayev, a Jewish Red Army soldier imprisoned at Sobibor.