Heinrich Oster (9 May 1878 – 29 October 1954) was a German chemist, executive at BASF and IG Farben and convicted Nazi war criminal.

[1] Oster was wounded early in the war, losing his left eye as a result, and so most of his service was as a member of staff to the Commander of the German Army in Alsace, as well as in matters of arms procurement to BASF.

[1] Oster was admitted to the Vorstand of their parent company IG Farben in 1926 as an alternate member and held a number of other posts of responsibility at the company, including membership of the board's Working Committee, the post of managing director of the Nitrogen Syndicate and membership of the Subcommittee for Fertilizers and Explosives.

[2] Oster held sponsoring membership of the Schutzstaffel from 1935 to 1939, a position which entitled him to officer rank in the black uniformed movement.

[1] Oster was arrested by the occupying American forces in 1946 and the following year was charged with war crimes as part of the IG Farben trial.