Franz Camille Overbeck (16 November 1837 – 26 June 1905) was a Russian-born German Protestant theologian. In Anglo-American discourse, he is perhaps best known in regard to his friendship with Friedrich Nietzsche; in German theological circles, Overbeck remains discussed for his own contributions.

Franz Overbeck was born in Saint Petersburg as a German citizen to Franz Heinrich Herrmann Overbeck, a German-British merchant, and his wife, Jeanne Camille Cerclet, who was born in Saint Petersburg to a French family. Consequently, his upbringing was European and humanistic: first taking place in Saint Petersburg, then in Paris from 1846 until the February Revolution of 1848, once again in Saint Petersburg, and after 1850 in Dresden. This international education helped him gain fluency in the most important European languages.

From 1856 until 1864, Overbeck studied theology in Leipzig, Göttingen, Berlin, and Jena. Primarily through the lectures of Karl Schwarz and in conjunction with the historical theology of Ferdinand Christian Baur, his studies situated him at the beginning of academic criticism against the official theology. In 1859, he received his doctorate degree, after which he worked on his Habilitation on Hippolytus until 1864. After 1864, he taught as a Privatdozent in Jena.

During his student time in Leipzig, he became close friends with Heinrich von Treitschke, and in Göttingen, Overbeck had become a member of Burschenschaft Hannovera.

In 1870, Overbeck became professor of New Testament Exegesis and Old Church History at the University of Basel. From that time until 1875, he lived in the same house (one floor under) as his colleague Friedrich Nietzsche, the Professor of Classical Philology at the same university. During this time, the housemates developed a friendship that would remain crucial for each other.

In 1873, Overbeck published his most important work 'How Christian is Our Present-Day Theology?' (Über die Christlichkeit unserer heutigen Theologie), in which he argued that the "historical" Christianity, as developed by the fathers of the church, neither did nor could have to do with the original ideas of Christ. He observed that early Christianity had opposed itself to every type of history, culture, and science, which made a "Christian theology" impossible. In this work, Overbeck criticized the conservative ("apologetic") theology, which stuck dogmatically to doctrines, as much as the "liberal" theology, which asserted that belief and knowledge could be reconciled. According to Overbeck, both failed to capture an essence of Christianity, which excludes every type of scientific knowledge.

This work was primarily incited by David Strauss's The Old and New Faith (Vom alten und neuen Glauben, 1872) and Paul de Lagarde's 'On the Relationship of the German State to Theology, Church, and Religion' ('Über das Verhältnis des deutschen Staates zu Theologie, Kirche und Religion', 1873). Both authors attempted to shape a modern Christian religion with the help of theological scholarship. Overbeck regarded this project as impossible and fundamentally in error. In his afterword for the second edition in 1903, he renewed this critique against theologian Adolf von Harnack and his work 'The Essence of Christianity' ('Das Wesen des Christentums', 1900).

The publication of this book practically destroyed all his chances to become professor at a German university. He remained in Basel, and for more than ten years, he held the same introductory lecture without addressing his provocative theses.