A microgrid is a collection of distributed energy resources, storage and loads under common coordination and control that provides a single functional interface to enable its management as a single unit. Microgrids provide several advantages such as power quality control, uninterrupted power supply and integration of renewable resources. However, microgrids are increasingly connected to the Internet for remote control and management, which makes them susceptible to cyber attacks. To address this issue, several pilot deployments have implemented bolt-on security mechanisms, typically focused on securing the protocols used in microgrids. Unfortunately, these solutions are inadequate because they fail to address some important cyber security requirements.This chapter describes the μGridSec methodology, which is intended to provide comprehensive cyber security solutions for microgrid deployments. First, cyber security requirements are derived from relevant industry standards and by studying pilot microgrid deployments. Next, the μGridSec methodology is applied to ensure that appropriate mechanisms are applied to microgrid architectures to meet the cyber security requirements. Finally, a high-level threat model for a representative microgrid architecture is used to identify security threats and demonstrate how μGridSec can address the threats.