Monad

Monad may refer to:

Philosophy
 Monad (philosophy), a term meaning "unit" used by philosophers to signify various entities 
Monadology by Gottfried Leibniz
 Monism, the concept of "one essence" in  the metaphysical and theological theory
 Monad (Gnosticism), the most primal aspect of God in Gnosticism
 Monadologia Physica, by Immanuel Kant

Science and technology
 Monad (category theory), a construction in category theory
 Monad (functional programming), functional programming constructs that capture various notions of computation
 Monad (linear algebra), a 3-term complex
 Monad (non-standard analysis), the set of points infinitesimally close to a given point
 Monad shell, code name for the PowerShell command line interface for Microsoft Windows
 Monad (biology), a historical term for a simple unicellular organism