Film assemblies of monolayer-protected clusters (MPCs) can serve as a functional component of protein monolayer electrochemistry systems. While the many unique properties of nanoparticles have made them a target for acting as scaffolding for the immobilization and analysis of redox proteins, the electrochemisty of such an interface is not understood. Here, different types of MPC film assemblies are used to study and control the electrochemistry of adsorbed cytochrome c (cyt c), including both non-faradaic and faradaic components of the observed voltammetry. A critical component of a well-defined electrochemical response from adsorbed cyt c is the effective discrimination of charging current, a factor we find to be directly related to the architecture of the MPC film. The electrochemical response of cyt c can be significantly controlled by engineering individual MPCs comprising the outer layer of the film assemblies. Constructed several nanometers thick to negate the heterogeneity of the adsorption sites, the observed electron transfer rate of cyt c is largely unaffected by having to traverse the thick nanoparticle film. The introduction of hydrophilic nanoparticles at the adsorption interface allows for maximum, molecular-level control of the surface interactions promoting cyt c adsorption, resulting in near ideal voltammetry of the protein. MPC film assemblies are shown as useful tools for advancing this powerful electrochemical technique for studying biological ET.