Peter Aloys Gratz (17 August 1769, Oy-Mittelberg – 1 November 1849) was a German schoolmaster and widely published Biblical scholar, who contributed to debates within Catholicism in the early nineteenth century.
In 1812 he published Neuer Versuch, die Entstehung der drei ersten Evangelien zu erklären (Stuttgart, 1812), in which he adopted the hypothesis of a Hebrew original as the basis of one of the Synoptic Gospels.
This work attracted the attention of scholars, and won for him on 28 September of the same year the chairs of Greek language and Biblical hermeneutics in the University of Ellwangen.
The university, though now devoid of the Rationalism and Febronianism which characterized the first period of its existence, was gradually undergoing the influence of a new movement known as Hermesianism, the originator of which was George Hermes, professor of theology and a close friend of Gratz.
The high reputation of Hermes, the popular character of his lectures, as well as the fact that they were devoted to the examination of the philosophical systems of Kant and Fichte, induced Gratz to sympathize with his distinguished friend and associate himself with the new movement.