A new and versatile method to prepare Ag nanoparticles on functionalized graphene sheets is described. In a first step, pyridine‐pyridazine units are introduced on graphene sheets by cycloaddition reaction with a tetrazine derivative. Then the material is coated on an electrode and electrodeposition is carried out to generate silver nanoparticles in a one‐step electroreduction process. The applied potential signal is shown to influence the size and dispersity of the particles in the composite. While larger particles are active in improving sensitivity of Surface‐Enhanced Raman Spectroscopy, smaller ones can be efficiently used in electrocatalysis, like for oxygen reduction. Both effects are demonstrated to highlight the versatility of the applications of these easily prepared nanocomposites.