Horst Paul Silvester Fischer (31 December 1912 – 8 July 1966) was a German medical doctor and member of the SS who participated in selections in Auschwitz-Birkenau concentration camp during World War II.

In a high-profile public case tried directly by the Supreme Court of East Germany, Fischer, the highest-ranking concentration camp doctor to ever stand trial in front of a German court, was found guilty of crimes against humanity and condemned to death.

He was involved in the early stages of the German invasion of the Soviet Union, but was recalled from the front in 1942, after falling ill with tuberculosis.

[2] During his time at Auschwitz-Birkenau concentration camp and its subcamps, Fischer was complicit in the murders of tens of thousands of prisoners by performing selections at the ramp, in the prison hospital, on the roll-call grounds, in the barracks as well as among the work units.

On 21 June 1944, Fischer was promoted to Hauptsturmführer, making him one of the highest ranking SS doctors in Auschwitz.

[4] After the war, Fischer got his SS blood group tattoo removed to avoid detection.

Fischer practiced medicine in the countryside under an alias, giving examinations and vaccinations to kindergarteners.

[citation needed] On 6 April 1960, a West German court in Ludwigsburg issued a warrant for Fischer's arrest, but failed to locate his whereabouts.

Fearing he would try to flee west or elsewhere, or commit suicide, officials did not reveal their investigation until Fischer had been remanded to Hohenschönhausen Prison.

The trial lasted roughly a week, and Fischer was found guilty of crimes against humanity.