The Encyclopaedia of the Philosophical Sciences (abbreviated as EPS or simply Encyclopaedia; German: Enzyklopädie der philosophischen Wissenschaften im Grundrisse, EPW, translated as Encyclopedia of the Philosophical Sciences in Basic Outline) by Georg Wilhelm Friedrich Hegel (first published in 1817, second edition 1827, third edition 1830), is a work that presents an abbreviated version of Hegel's systematic philosophy in its entirety, and is the only form in which Hegel ever published his entire mature philosophical system. The fact that the account is exhaustive, that the grounding structures of reality are ideal, and that the system is closed makes the Encyclopedia a statement par excellence of absolute idealism.

Intended as a pedagogical aid for attendees of his lectures, Hegel revised and extended the Encyclopedia over more than a decade, but stressed its role as a "textbook" in need of elucidation through oral commentary. The 1830 text is widely available in various English translations with copious additions (Zusätze) added posthumously by Hegel's students, deriving from their lecture notes. These additions expand on the text with examples and illustrations, and while scholars do not take the Zusätze to be verbatim transcription of Hegel's lectures, their more informal and non-technical style make them good stand-ins for the "necessary oral commentary".

Part I of the work is sometimes referred to as the Lesser Logic (or Shorter Logic) to distinguish it from the Greater Logic, the moniker given to Hegel's Science of Logic.