We present a brief theoretical overview of rare kaon decays both in and beyond the Standard Model. The Standard Model contributions to K+ → &pgr;+&ngr;&ngr;, KL → &pgr;0&ngr;&ngr;, and KL → &pgr;0ee are analyzed in detail, followed by a discussion of alternative theoretical frameworks that could modify the Standard Model predictions. Special attention is paid to ‘‘direct’’ supersymmetric flavor‐changing neutral currents induced by renormalization‐group scaling in minimal and in non‐minimal supersymmetry. We emphasize the importance of rare decays as a sensitive probe of physics beyond the Standard Model.