Samuel Oppenheimer (21 June 1630 – 3 May 1703) was an Ashkenazi Jewish banker, imperial court diplomat, factor, and military supplier for the Holy Roman Emperor.

Although the Jews had been recently expelled from Vienna in 1670, the emperor permitted Oppenheimer to settle there, together with his "Gesinde", his followers, who included a number of Jewish families.

He was appointed "Oberfaktor" and court Jew at the recommendation of Margrave Ludwig of Baden, the imperial general in Hungary, to whom he had advanced 100,000 gulden for war expenses.

Oppenheimer took steps to suppress the anti-Semitic Entdecktes Judenthum (Judaism Unmasked) treatise by spending large sums of money to win the court and the Jesuits to the side of the Jews.

This amount was based on a sum which (with compound interest), according to the state, Oppenheimer had allegedly obtained by fraud at the beginning of his career.

He also paid ransom for the return of Jews captured during the Turkish wars and supported as well R. Judah he-Hasid's voyage to Erez Israel in 1700.