Friedrich Heinrich Jacobi (January 25, 1743 – March 10, 1819) is an influential German philosopher, literary figure, socialite, and the younger brother of poet Johann Georg Jacobi.

He is notable for popularizing the term nihilism (coined by Obereit in 1787) and promoting it as the prime fault of Enlightenment thought particularly in the philosophical systems of Baruch Spinoza, Immanuel Kant, Johann Fichte and Friedrich Schelling.[

Instead of speculative reason, he advocates Glaube (variously translated as faith or "belief") and revelation.

In this sense, Jacobi anticipates present-day writers who criticize secular philosophy as relativistic and dangerous for religious faith.

In his time, he is also well-known among literary circles for his critique of the Sturm and Drang movement, and implicitly close associate Johann Wolfgang von Goethe, and its visions of atomized individualism.

His literary projects are devoted to the reconciliation of Enlightenment individualism with social obligation.