We demonstrate a redox‐active, crystalline donor–acceptor (D‐A) assembly in which the electron transfer (ET) process can be reversibly switched. This ET process, induced by a guest‐responsive structural transformation at room temperature, is realized in a porous, metal–organic framework (MOF), having anthracene (D)–naphthalenediimide (A) as struts. A control MOF structure obtained by a solvent‐assisted linker exchange (SALE) method, replacing an acceptor strut with a neutral one, supported the switchable electronic states in the D‐A MOF. Combined investigations with X‐ray diffraction, spectroscopy, and theoretical analyses revealed the dynamic metal paddle‐wheel node as a critical unit for controlling structural flexibility and the corresponding unprecedented ET process.