Leonardo Conti (German pronunciation: [ˈleːonaʁdo ˈkɔnti]; 24 August 1900 – 6 October 1945) was the Reich Health Leader and an SS-Obergruppenführer in Nazi Germany.

He was involved in the planning and execution of Action T4 that murdered hundreds of thousands of adults and children with severe mental and physical handicaps.

In the summer of 1918, he volunteered for military service in the First World War with the Imperial German Army's 54th Field Artillery Regiment in Küstrin (today, Kostrzyn nad Odrą).

After this organization was banned by the government in July 1922, Conti enrolled in the Viking League, another right-wing group committed to the overthrow of the Weimar Republic.

However, in September 1930, Conti, who had reached the rank of SA-Oberführer, was expelled from the SA when he came into conflict with Walter Stennes, at that time the commander of SA-Gruppe Ost.

After the Nazi seizure of power, Conti was given a number of official positions in the German government, mostly in the areas of medicine and health.

This was followed on 28 August by Adolf Hitler appointing him State Secretary for Public Health and Nursing in the Reich and Prussian Ministry of the Interior.

[3] Conti attempted to have the use of the methamphetamine Pervitin (see History and culture of substituted amphetamines) restricted by the Wehrmacht, which had been issuing millions of tablets to their soldiers and airmen.

Under his leadership, local health offices were further expanded to allow for genetic control and selection of the population in order to remove "weak" elements for the improvement of the German race, a doctrine known as eugenics.

Conti worked with Dr. Karl Brandt to draft plans for the extermination of all Germany's mental patients along with those suffering from severe physical handicaps.