This chapter describes static defense strategies for securing industrial control systems, highlighting their critical importance. It details seven key strategies, including application whitelisting, configuration management, and attack surface reduction. The chapter provides real-world examples and evaluates the effectiveness of these strategies. It also explores dynamic defense measures, such as network segmentation and device hardening, emphasizing their role in reducing threat exposure. The chapter covers regulatory compliance with frameworks like NERC CIP and HIPAA, underlining their importance. Additionally, readers will gain insights into industrial control system communication technology migration and defense-in-depth strategies for proactive security. Risk management aspects, including risk identification, mitigation, and monitoring, are also discussed. The chapter further explores the technologies employed in static defense and potential implementation challenges. By understanding these concepts, readers will be equipped to implement layered security measures to protect their industrial control system environments.