Alfred Ploetz (22 August 1860 – 20 March 1940) was a German physician, biologist, Social Darwinist, and eugenicist known for coining the term racial hygiene (Rassenhygiene),[1] a form of eugenics, and for promoting the concept in Germany.

In Gerhart Hauptmann's drama Vor Sonnenaufgang ("Before Sunrise"), which was first performed on 20 October 1889 in Berlin, the key figure of the journalist Loth was based on Ploetz.

After he had finished school, Ploetz at first studied political economy in Breslau, where he joined the "Freie Wissenschaftliche Vereinigung" (Free Scientific Union).

In consequence of the prosecution of socialistically-minded persons in application of Otto von Bismarck's antisocialist laws (1878–1890), Ploetz in 1883 fled to Zürich, where he continued to study political economy with Julius Platter (1844–1923).

In his memoirs, Ploetz stated as an important reason for his choice of Zürich that in his studies in Breslau, socialist theories had been only incidentally mentioned.

In 1933, Reich Interior Minister Wilhelm Frick established an "expert advisory committee for population and racial policy", which included Ploetz, Fritz Lenz, Ernst Rüdin and Hans F.K.

[12] In his book The Excellence of Our Race and the Protection of the Weak (1895), Ploetz coined the term "racial hygiene" (German: Rassenhygiene); he described a society in which eugenic ideas would be applied.

[5] The publication endorsed a Social Darwinist interpretation of race and solidified genetic determinist ideas about the "evolutionary superiority of the German Volk".

Ploetz found the idea horrible and suggested a humane alternative of simply encouraging only "fit" people to reproduce, but he called that a weak proposal.

He stressed that the distinctiveness of Jews indicated that their mental characteristics would adversely affect Aryans by introducing individualism and lack of love for the military and the nation.