The electrified electrode–electrolyte interface plays a central role in electrochemical processes because it is in this region that the redox reactions occur. However, current understanding of the structural and electronic properties of electrified interfaces remains limited. To narrow this knowledge gap, numerical modeling techniques at various scales have recently been developed. In this chapter, the influence of the applied bias potential on interfacial processes is explored. Recent developments in classical force-field-based molecular dynamics and first-principles electrochemistry simulation methodologies for simulating the dynamic nature of these interfaces are summarized with consideration of the requirement for charge neutrality and alignment of the reference potential. Relevant case studies are also presented to highlight the advantages and disadvantages of the various methods.