Concluding Unscientific Postscript to the Philosophical Fragments (Danish: Afsluttende uvidenskabelig Efterskrift til de philosophiske Smuler) is a major work by Søren Kierkegaard. The work is an attack against Hegelianism, the philosophy of Hegel, and especially Hegel's Science of Logic. The work is also famous for its dictum, Subjectivity is Truth. It was an attack on what Kierkegaard saw as Hegel's deterministic philosophy. Against Hegel's system, Kierkegaard is often interpreted as taking the side of metaphysical libertarianism or free will, though it has been argued that an incompatibilist conception of free will is not essential to Kierkegaard's formulation of existentialism.

As the title suggests, the Postscript is sequel to the earlier Philosophical Fragments. The title of the work is ironic because the Postscript is almost five times larger than the Fragments. The Postscript credits "Johannes Climacus" as the author and Kierkegaard as its editor. Like his other pseudonymous works, the Postscript is not a reflection of Kierkegaard's own beliefs. However, unlike his other pseudonymous works, Kierkegaard attaches his name as editor to this work, showing the importance of the Postscript to Kierkegaard's overall authorship.