Bruno Bauer (September 6, 1809 – April 13, 1882) is a German philosopher and historian.

As a student of G. W. F. Hegel, Bauer is a radical Rationalist in philosophy, politics and Biblical criticism.

Bauer investigates the sources of the New Testament and, beginning with Hegel's Hellenophile orientation, concludes that early Christianity owes more to ancient Greek philosophy (Stoicism) than to Judaism.

Bruno Bauer is also known by his association and sharp break with Karl Marx and Friedrich Engels, and by his later association with Max Stirner and Friedrich Nietzsche.

Starting in 1840, he begins a series of works arguing that Jesus was a second-century fusion of Jewish, Greek, and Roman theology.